United Airlines Flight 736
Encyclopedia
United Airlines Flight 736 was a daily U.S. transcontinental passenger flight
operated by United Airlines
that crashed on April21, 1958. The aircraft assigned to Flight 736, a Douglas DC-7
airliner carrying 47 persons, was flying at cruise altitude
above Clark County, Nevada
, en route to a stopover at Denver, Colorado when it became involved in a mid-air collision
with a United States Air Force
fighter jet crewed by two pilots. The collision occurred at 8:30 a.m. in clear weather within a major commercial airway
; both aircraft fell out of control from 21000 feet (6,400.8 m) and crashed into unpopulated desert southwest of Las Vegas, Nevada
..
There were no survivors from either aircraft, and with 49 fatalities it remains the deadliest crash in the history of the Las Vegas metropolitan area
. Among the victims were a group of military personnel and civilian contractors involved with sensitive Department of Defense weapons systems. The loss of the group triggered new rules prohibiting similar groups engaged in critical projects from flying aboard the same aircraft.
The official investigation stated that cockpit
visibility limitations played a role in the accident, but also faulted military and civilian aviation authorities for not taking measures to reduce well-known collision risks that had existed for over a year within the confines of airways, despite numerous complaints from airline crews. The loss of United Airlines Flight 736—part of a series of 1950s mid-air collisions in American skies, including the well-publicized 1956 Grand Canyon mid-air collision
—helped usher in widespread improvements in air traffic control
within the United States.
with aircraft registration
N6328C, departed Los Angeles International Airport
at 7:37 a.m. on a flight to New York City with stops in Denver, Kansas City and Washington, D.C. On board were 42 passengers and five crew members; Captain Duane M. Ward, 44, First Officer Arlin Edward Sommers, 36, Flight Engineer Charles E. Woods, 43, and Stewardesses Pauline Mary Murray, 22, and Yvonne Marie Peterson, 27. Of the passengers on the flight, seven were military personnel and 35 were civilians.
Soon after takeoff the airliner was directed into airway "Victor 8," on a route that took it east over Ontario, California, and then northeast toward Las Vegas. The crew flew the DC-7 under instrument flight rules
, controlled by Civil Aeronautics Authority (CAA) ground stations, at an authorized altitude of 21000 feet (6,400.8 m) toward the first stopover at Denver.
At 8:14 a.m. the United Airlines crew radioed a routine position report over the Mojave Desert to notify controllers that they expected to arrive over McCarran Field near Las Vegas at 8:31 a.m.
At 7:45 a.m. a U.S. Air Force F-100F-5-NA Super Sabre
jet fighter, serial number
56-3755, departed Nellis Air Force Base
near Las Vegas on a training flight with two pilots on board. In the front seat of the tandem cockpit was flight instructor
and safety pilot
Capt. Thomas N. Coryell, 29, and behind him sat his student, 1st Lt.
Gerald D. Moran, 24, who as part of his training would spend the flight under a hood that blocked his view outside the aircraft, but allowed him to see his instrument panel.
The instructor had two-way microphone communication with the student, and his duties were to instruct the student in the rear seat, monitor his performance and maintain a lookout for other aircraft. The F-100F had dual pilot control and the instructor could take over flying the jet at any time. The training flight involved a descent and approach
to Nellis Air Force Base under simulated instrument meteorological conditions
from an altitude of 28000 feet (8,534.4 m). The descent was to be a 'teardrop pattern,' with the Las Vegas commercial radio station KRAM as the navigational fix
, a process that was referred to as the 'KRAM procedure.' The prescribed descent angle for the KRAM procedure was about five degrees.
Pilot Moran radioed the control tower at Nellis Air Force Base at 8:28 a.m. to report that he would now begin a procedural "jet penetration" descent to 14000 feet (4,267.2 m). As the fighter descended, the airliner was approaching Las Vegas air space at about 312 knots on a heading
of 23degrees, flying straight-and-level within the confines of its designated airway. The CAA stations controlling the airliner were unaware of the fighter jet; the Air Force controllers at Nellis Air Force Base directing the jet were unaware of the airliner.
The descending Air Force jet, flying at 444 knots, had clipped the airliner's right wing with its own right wing, immediately sending both aircraft out of control. At the moment of collision the F-100F was in a 90degree bank to the left at a down angle of about 17 degrees. One eyewitness to the collision stated that about two seconds before the collision the wings of the F-100F "dipped"; another eyewitness said the fighter "swooped down" just before the impact. The witness descriptions and the extreme 90 degree bank of the fighter jet—far more than the 30 degrees outlined in the KRAM procedure—suggest an unsuccessful "last second" evasive action on the part of the Air Force crew.
Moments after the two planes collided, the only mayday distress call
radioed by the United Airlines crew was heard at 8:30 a.m. plus 20 seconds. The crippled airliner—now missing about eight feet (2.5 m) of its right wing—trailed black smoke and flames as it spiraled earthward, and crashed into a then-empty patch of desert outside the town of Arden
. The nearly vertical impact and subsequent explosion instantly killed everyone on board.
The fighter jet—its right wing and right tailplane
torn away by the collision—left a trail of fragments as it arced downward, and crashed west of the small community of Sloan
into a hilly area of uninhabited desert, several miles south of the DC-7 crash site. At least one of the Air Force pilots was still in the jet when it hit the ground, but contemporary news reports differ on whether the other pilot managed an unsuccessful ejection at too low an altitude to survive, or stayed with the jet all the way to the ground.
Witnesses reported seeing a parachute drifting away from the falling F-100F, leading to the hope that a pilot had ejected, but when the parachute was located it was determined to be a drag parachute
that is meant to be deployed on landing to help slow the fighter down.
At the request of the local sheriff and United Airlines, the Federal Bureau of Investigation
sent fingerprint experts to help identify the human remains. The Los Angeles Times
reported that among the dead were 13 civilian and military managers, engineers and technicians assigned to the American ballistic missile
program. Articles in the Las Vegas Review-Journal
commemorating the 40th and 50th anniversaries of the crash reported that the FBI search went beyond fingerprint matching for identification; the agents were also looking for any surviving sensitive papers relating to national security
that the group of military contractors had carried on board in handcuffed briefcases. The same reports also said the crash prompted the military and defense industry to adopt rules to keep groups of technical people involved in the same critical project from traveling together on the same plane.
The Civil Aeronautics Board (CAB) conducted an investigation and published a report on the accident. The CAB ruled out the weather conditions and the airworthiness
of the two planes as factors in the collision. The report stated the probable cause was the high rate of near head-on closure, and that at high altitude, there were human and cockpit limitations involved. Analysis of the approach angles concluded that a metal frame support on the F-100's canopy "interfered seriously" with detection of the DC-7, and a supporting pillar on the DC-7's windshield
may have hindered sighting the fighter.U.S. Air Force F-100F
|image = United Airlines Flight 736 DC-7 collected debris.jpg|alt=Vertical tail that has torn from the DC-7 lays flat in the foreground. The letters U N I are clearly visible on an intact section. The rudder is mostly missing. A few fragments are placed near where the missing rudder would be. Unidentifiable pieces of wreckage are arrayed in another grouping in the background.
|caption = Some of the Douglas DC-7 aircraft wreckage collected for the crash investigation.
|date = April 21, 1958
|type = Mid-air collision
|occurrence_type = Accident
|site = Arden, Nevada
, USA
|total_fatalities = 49
|total_survivors = 0
|plane1_type = Douglas DC-7
|plane1_operator = United Airlines
|plane1_tailnum =
|plane1_name =
|plane1_origin = Los Angeles, California
|plane1_stopover0 = Denver, Colorado
|plane1_stopover1 = Kansas City, Missouri
|plane1_laststopover = Washington, D.C.
|plane1_destination = New York City
|plane1_passengers = 42
|plane1_crew = 5
|plane1_survivors = 0
|plane2_type = North American F-100F-5-NA Super Sabre
|plane2_operator = United States Air Force
|plane2_tailnum = 56-3755
|plane2_image = F-100-356tfs-1960.jpg|alt=Side view of a jet fighter being refueled in flight. The jet has a natural metal finish with large air force lettering and insignia on the fuselage. Two pilots are inside the transparent cockpit canopy. Large streamlined drop tanks hang beneath each wing. A refueling hose is docked with a probe extending from one wing.
|plane2_squadron =
|plane2_name =
|plane2_origin = Nellis Air Force Base, Nevada
|plane2_destination = Nellis Air Force Base
|plane2_passengers =
|plane2_crew = 2
|plane2_survivors = 0
}}
United Airlines Flight 736 was a daily U.S. transcontinental passenger flight
operated by United Airlines
that crashed on April21, 1958. The aircraft assigned to Flight 736, a Douglas DC-7
airliner carrying 47 persons, was flying at cruise altitude
above Clark County, Nevada
, en route to a stopover at Denver, Colorado when it became involved in a mid-air collision
with a United States Air Force
fighter jet crewed by two pilots. The collision occurred at 8:30 a.m. in clear weather within a major commercial airway
; both aircraft fell out of control from 21000 feet (6,400.8 m) and crashed into unpopulated desert southwest of Las Vegas, Nevada
..
There were no survivors from either aircraft, and with 49 fatalities it remains the deadliest crash in the history of the Las Vegas metropolitan area
. Among the victims were a group of military personnel and civilian contractors involved with sensitive Department of Defense weapons systems. The loss of the group triggered new rules prohibiting similar groups engaged in critical projects from flying aboard the same aircraft.
The official investigation stated that cockpit
visibility limitations played a role in the accident, but also faulted military and civilian aviation authorities for not taking measures to reduce well-known collision risks that had existed for over a year within the confines of airways, despite numerous complaints from airline crews. The loss of United Airlines Flight 736—part of a series of 1950s mid-air collisions in American skies, including the well-publicized 1956 Grand Canyon mid-air collision
—helped usher in widespread improvements in air traffic control
within the United States.
with aircraft registration
N6328C, departed Los Angeles International Airport
at 7:37 a.m. on a flight to New York City with stops in Denver, Kansas City and Washington, D.C. On board were 42 passengers and five crew members; Captain Duane M. Ward, 44, First Officer Arlin Edward Sommers, 36, Flight Engineer Charles E. Woods, 43, and Stewardesses Pauline Mary Murray, 22, and Yvonne Marie Peterson, 27. Of the passengers on the flight, seven were military personnel and 35 were civilians.
Soon after takeoff the airliner was directed into airway "Victor 8," on a route that took it east over Ontario, California, and then northeast toward Las Vegas. The crew flew the DC-7 under instrument flight rules
, controlled by Civil Aeronautics Authority (CAA) ground stations, at an authorized altitude of 21000 feet (6,400.8 m) toward the first stopover at Denver.
At 8:14 a.m. the United Airlines crew radioed a routine position report over the Mojave Desert to notify controllers that they expected to arrive over McCarran Field near Las Vegas at 8:31 a.m.
At 7:45 a.m. a U.S. Air Force F-100F-5-NA Super Sabre
jet fighter, serial number
56-3755, departed Nellis Air Force Base
near Las Vegas on a training flight with two pilots on board. In the front seat of the tandem cockpit was flight instructor
and safety pilot
Capt. Thomas N. Coryell, 29, and behind him sat his student, 1st Lt.
Gerald D. Moran, 24, who as part of his training would spend the flight under a hood that blocked his view outside the aircraft, but allowed him to see his instrument panel.
The instructor had two-way microphone communication with the student, and his duties were to instruct the student in the rear seat, monitor his performance and maintain a lookout for other aircraft. The F-100F had dual pilot control and the instructor could take over flying the jet at any time. The training flight involved a descent and approach
to Nellis Air Force Base under simulated instrument meteorological conditions
from an altitude of 28000 feet (8,534.4 m). The descent was to be a 'teardrop pattern,' with the Las Vegas commercial radio station KRAM as the navigational fix
, a process that was referred to as the 'KRAM procedure.' The prescribed descent angle for the KRAM procedure was about five degrees.
Pilot Moran radioed the control tower at Nellis Air Force Base at 8:28 a.m. to report that he would now begin a procedural "jet penetration" descent to 14000 feet (4,267.2 m). As the fighter descended, the airliner was approaching Las Vegas air space at about 312 knots on a heading
of 23degrees, flying straight-and-level within the confines of its designated airway. The CAA stations controlling the airliner were unaware of the fighter jet; the Air Force controllers at Nellis Air Force Base directing the jet were unaware of the airliner.
The descending Air Force jet, flying at 444 knots, had clipped the airliner's right wing with its own right wing, immediately sending both aircraft out of control. At the moment of collision the F-100F was in a 90degree bank to the left at a down angle of about 17 degrees. One eyewitness to the collision stated that about two seconds before the collision the wings of the F-100F "dipped"; another eyewitness said the fighter "swooped down" just before the impact. The witness descriptions and the extreme 90 degree bank of the fighter jet—far more than the 30 degrees outlined in the KRAM procedure—suggest an unsuccessful "last second" evasive action on the part of the Air Force crew.
Moments after the two planes collided, the only mayday distress call
radioed by the United Airlines crew was heard at 8:30 a.m. plus 20 seconds. The crippled airliner—now missing about eight feet (2.5 m) of its right wing—trailed black smoke and flames as it spiraled earthward, and crashed into a then-empty patch of desert outside the town of Arden
. The nearly vertical impact and subsequent explosion instantly killed everyone on board.
The fighter jet—its right wing and right tailplane
torn away by the collision—left a trail of fragments as it arced downward, and crashed west of the small community of Sloan
into a hilly area of uninhabited desert, several miles south of the DC-7 crash site. At least one of the Air Force pilots was still in the jet when it hit the ground, but contemporary news reports differ on whether the other pilot managed an unsuccessful ejection at too low an altitude to survive, or stayed with the jet all the way to the ground.
Witnesses reported seeing a parachute drifting away from the falling F-100F, leading to the hope that a pilot had ejected, but when the parachute was located it was determined to be a drag parachute
that is meant to be deployed on landing to help slow the fighter down.
At the request of the local sheriff and United Airlines, the Federal Bureau of Investigation
sent fingerprint experts to help identify the human remains. The Los Angeles Times
reported that among the dead were 13 civilian and military managers, engineers and technicians assigned to the American ballistic missile
program. Articles in the Las Vegas Review-Journal
commemorating the 40th and 50th anniversaries of the crash reported that the FBI search went beyond fingerprint matching for identification; the agents were also looking for any surviving sensitive papers relating to national security
that the group of military contractors had carried on board in handcuffed briefcases. The same reports also said the crash prompted the military and defense industry to adopt rules to keep groups of technical people involved in the same critical project from traveling together on the same plane.
The Civil Aeronautics Board (CAB) conducted an investigation and published a report on the accident. The CAB ruled out the weather conditions and the airworthiness
of the two planes as factors in the collision. The report stated the probable cause was the high rate of near head-on closure, and that at high altitude, there were human and cockpit limitations involved. Analysis of the approach angles concluded that a metal frame support on the F-100's canopy "interfered seriously" with detection of the DC-7, and a supporting pillar on the DC-7's windshield
may have hindered sighting the fighter.U.S. Air Force F-100F
|image = United Airlines Flight 736 DC-7 collected debris.jpg|alt=Vertical tail that has torn from the DC-7 lays flat in the foreground. The letters U N I are clearly visible on an intact section. The rudder is mostly missing. A few fragments are placed near where the missing rudder would be. Unidentifiable pieces of wreckage are arrayed in another grouping in the background.
|caption = Some of the Douglas DC-7 aircraft wreckage collected for the crash investigation.
|date = April 21, 1958
|type = Mid-air collision
|occurrence_type = Accident
|site = Arden, Nevada
, USA
|total_fatalities = 49
|total_survivors = 0
|plane1_type = Douglas DC-7
|plane1_operator = United Airlines
|plane1_tailnum =
|plane1_name =
|plane1_origin = Los Angeles, California
|plane1_stopover0 = Denver, Colorado
|plane1_stopover1 = Kansas City, Missouri
|plane1_laststopover = Washington, D.C.
|plane1_destination = New York City
|plane1_passengers = 42
|plane1_crew = 5
|plane1_survivors = 0
|plane2_type = North American F-100F-5-NA Super Sabre
|plane2_operator = United States Air Force
|plane2_tailnum = 56-3755
|plane2_image = F-100-356tfs-1960.jpg|alt=Side view of a jet fighter being refueled in flight. The jet has a natural metal finish with large air force lettering and insignia on the fuselage. Two pilots are inside the transparent cockpit canopy. Large streamlined drop tanks hang beneath each wing. A refueling hose is docked with a probe extending from one wing.
|plane2_squadron =
|plane2_name =
|plane2_origin = Nellis Air Force Base, Nevada
|plane2_destination = Nellis Air Force Base
|plane2_passengers =
|plane2_crew = 2
|plane2_survivors = 0
}}
United Airlines Flight 736 was a daily U.S. transcontinental passenger flight
operated by United Airlines
that crashed on April21, 1958. The aircraft assigned to Flight 736, a Douglas DC-7
airliner carrying 47 persons, was flying at cruise altitude
above Clark County, Nevada
, en route to a stopover at Denver, Colorado when it became involved in a mid-air collision
with a United States Air Force
fighter jet crewed by two pilots. The collision occurred at 8:30 a.m. in clear weather within a major commercial airway
; both aircraft fell out of control from 21000 feet (6,400.8 m) and crashed into unpopulated desert southwest of Las Vegas, Nevada
..
There were no survivors from either aircraft, and with 49 fatalities it remains the deadliest crash in the history of the Las Vegas metropolitan area
. Among the victims were a group of military personnel and civilian contractors involved with sensitive Department of Defense weapons systems. The loss of the group triggered new rules prohibiting similar groups engaged in critical projects from flying aboard the same aircraft.
The official investigation stated that cockpit
visibility limitations played a role in the accident, but also faulted military and civilian aviation authorities for not taking measures to reduce well-known collision risks that had existed for over a year within the confines of airways, despite numerous complaints from airline crews. The loss of United Airlines Flight 736—part of a series of 1950s mid-air collisions in American skies, including the well-publicized 1956 Grand Canyon mid-air collision
—helped usher in widespread improvements in air traffic control
within the United States.
with aircraft registration
N6328C, departed Los Angeles International Airport
at 7:37 a.m. on a flight to New York City with stops in Denver, Kansas City and Washington, D.C. On board were 42 passengers and five crew members; Captain Duane M. Ward, 44, First Officer Arlin Edward Sommers, 36, Flight Engineer Charles E. Woods, 43, and Stewardesses Pauline Mary Murray, 22, and Yvonne Marie Peterson, 27. Of the passengers on the flight, seven were military personnel and 35 were civilians.
Soon after takeoff the airliner was directed into airway "Victor 8," on a route that took it east over Ontario, California, and then northeast toward Las Vegas. The crew flew the DC-7 under instrument flight rules
, controlled by Civil Aeronautics Authority (CAA) ground stations, at an authorized altitude of 21000 feet (6,400.8 m) toward the first stopover at Denver.
At 8:14 a.m. the United Airlines crew radioed a routine position report over the Mojave Desert to notify controllers that they expected to arrive over McCarran Field near Las Vegas at 8:31 a.m.
At 7:45 a.m. a U.S. Air Force F-100F-5-NA Super Sabre
jet fighter, serial number
56-3755, departed Nellis Air Force Base
near Las Vegas on a training flight with two pilots on board. In the front seat of the tandem cockpit was flight instructor
and safety pilot
Capt. Thomas N. Coryell, 29, and behind him sat his student, 1st Lt.
Gerald D. Moran, 24, who as part of his training would spend the flight under a hood that blocked his view outside the aircraft, but allowed him to see his instrument panel.
The instructor had two-way microphone communication with the student, and his duties were to instruct the student in the rear seat, monitor his performance and maintain a lookout for other aircraft. The F-100F had dual pilot control and the instructor could take over flying the jet at any time. The training flight involved a descent and approach
to Nellis Air Force Base under simulated instrument meteorological conditions
from an altitude of 28000 feet (8,534.4 m). The descent was to be a 'teardrop pattern,' with the Las Vegas commercial radio station KRAM as the navigational fix
, a process that was referred to as the 'KRAM procedure.' The prescribed descent angle for the KRAM procedure was about five degrees.
Pilot Moran radioed the control tower at Nellis Air Force Base at 8:28 a.m. to report that he would now begin a procedural "jet penetration" descent to 14000 feet (4,267.2 m). As the fighter descended, the airliner was approaching Las Vegas air space at about 312 knots on a heading
of 23degrees, flying straight-and-level within the confines of its designated airway. The CAA stations controlling the airliner were unaware of the fighter jet; the Air Force controllers at Nellis Air Force Base directing the jet were unaware of the airliner.
The descending Air Force jet, flying at 444 knots, had clipped the airliner's right wing with its own right wing, immediately sending both aircraft out of control. At the moment of collision the F-100F was in a 90degree bank to the left at a down angle of about 17 degrees. One eyewitness to the collision stated that about two seconds before the collision the wings of the F-100F "dipped"; another eyewitness said the fighter "swooped down" just before the impact. The witness descriptions and the extreme 90 degree bank of the fighter jet—far more than the 30 degrees outlined in the KRAM procedure—suggest an unsuccessful "last second" evasive action on the part of the Air Force crew.
Moments after the two planes collided, the only mayday distress call
radioed by the United Airlines crew was heard at 8:30 a.m. plus 20 seconds. The crippled airliner—now missing about eight feet (2.5 m) of its right wing—trailed black smoke and flames as it spiraled earthward, and crashed into a then-empty patch of desert outside the town of Arden
. The nearly vertical impact and subsequent explosion instantly killed everyone on board.
The fighter jet—its right wing and right tailplane
torn away by the collision—left a trail of fragments as it arced downward, and crashed west of the small community of Sloan
into a hilly area of uninhabited desert, several miles south of the DC-7 crash site. At least one of the Air Force pilots was still in the jet when it hit the ground, but contemporary news reports differ on whether the other pilot managed an unsuccessful ejection at too low an altitude to survive, or stayed with the jet all the way to the ground.
Witnesses reported seeing a parachute drifting away from the falling F-100F, leading to the hope that a pilot had ejected, but when the parachute was located it was determined to be a drag parachute
that is meant to be deployed on landing to help slow the fighter down.
At the request of the local sheriff and United Airlines, the Federal Bureau of Investigation
sent fingerprint experts to help identify the human remains. The Los Angeles Times
reported that among the dead were 13 civilian and military managers, engineers and technicians assigned to the American ballistic missile
program. Articles in the Las Vegas Review-Journal
commemorating the 40th and 50th anniversaries of the crash reported that the FBI search went beyond fingerprint matching for identification; the agents were also looking for any surviving sensitive papers relating to national security
that the group of military contractors had carried on board in handcuffed briefcases. The same reports also said the crash prompted the military and defense industry to adopt rules to keep groups of technical people involved in the same critical project from traveling together on the same plane.
The Civil Aeronautics Board (CAB) conducted an investigation and published a report on the accident. The CAB ruled out the weather conditions and the airworthiness
of the two planes as factors in the collision. The report stated the probable cause was the high rate of near head-on closure, and that at high altitude, there were human and cockpit limitations involved. Analysis of the approach angles concluded that a metal frame support on the F-100's canopy "interfered seriously" with detection of the DC-7, and a supporting pillar on the DC-7's windshield
may have hindered sighting the fighter. The CAB accident report also cited a failure of Nellis Air Force Base and the CAA to take measures to reduce a known collision exposure; training exercises were allowed to be conducted for more than a year prior to the collision within the confines of several airways, even after numerous near-misses
with military jets had been reported by airline crews.
The mid-air collision involving United Airlines Flight 736, and a second one month later over Maryland between a Capital Airlines
airliner and another military jet, accelerated efforts in the United States to change the way air space was allocated to commercial and military flights.
On April 22, 1958, the day after United Airlines Flight 736 crashed, the CAB proposed an experiment in which it would set aside part of the air space from which would be barred all aircraft lacking specific clearance to enter it. All aircraft operating in the designated space would have to be equipped for instrument flight operations. According to the CAB there had been 159 mid-air collisions in the years 1947-1957, and that in 1957 alone there were 971 near-misses. The increased speed of aircraft and higher air traffic density made it harder to give pilots enough time to spot each other during flights. Therefore, the CAB said, "it is essential that positive control
be extended to altitudes at 35,000feet and on additional routes as rapidly as practical." At the time such control only existed between 17,000 and 22,000feet on certain transcontinental airways.
In the wake of the two airliners lost in the April and May 1958 collisions, investigators from a House of Representatives committee—concerned about the lack of coordination between civil and military air traffic controllers—imposed a 60-day deadline on the CAB and the Air Force to establish new control procedures. The committee also said that eventually a single civil agency should be given the power to regulate all air space for all types of aircraft. Furthermore, the committee stated that military flying should be controlled in the vicinity of airways not only in instrument weather, but also in visual conditions
.
Four months after 49 lives were lost in the worst aviation accident in the history of the Las Vegas region, the Federal Aviation Act of 1958
was signed into law. The act dissolved the CAA and created the Federal Aviation Agency (FAA, later renamed Federal Aviation Administration
). The FAA was given unprecedented and total authority over the control of American air space, including military activity, and as procedures and ATC facilities were modernized, airborne collisions gradually decreased in frequency. The Las Vegas Review-Journal in a 50th anniversary article stated that the act "specifically referenced the crash of United 736 in ordering the creation of the FAA."
The supersonic F-100 left a legacy of many crashes over its years of service; nearly 25 percent were lost to accidents. In particular, 1958 was the most costly, with 47 F-100 pilots killed and 116 of the fighters destroyed, a loss rate averaging almost one every three days.
s seeking damages
were brought against United Airlines, the U.S. Government, or both. On September 24, 1958, United Airlines filed for damages—based on the Federal Tort Claims Act
—against the United States in the U.S. District Court for the District of Delaware. The airline alleged that the United States through its agents in the United States Air Force negligently
operated the F-100F, and sought damages of US$3,576,698. The court found neither crew was negligent for a failure to see and avoid each other, but held the United States was liable because of other negligence. The case was settled on December17, 1962, with the United States agreeing to pay the airline $1.45million.
In another case, on January 8, 1964 surviving relatives of two of the United Airlines crew were awarded a total of $343,200 from the government, with U.S. District Court Judge Hatfield Chilson finding the Air Force pilots did not use "ordinary care" in operation of the fighter jet, and should have yielded the right of way to the DC-7 airliner. Chilson also criticized the Air Force for not coordinating instrument training flights with civilian instrument flight rules traffic, and for failing to schedule flights to minimize traffic congestion. The government appeal
ed, and the relatives cross-appealed to have their damage awards increased, but the earlier 1964 judgment was affirmed on September 30, 1965.
and 21 others died in the mountainside crash of TWA Flight 3
, about 16 miles (25.7 km) WSW of where United Airlines Flight 736 crashed.
In 1964, 29 people lost their lives when Bonanza Air Lines Flight 114
flew into a hilltop 5 miles (8 km) SW of the United Airlines impact site; the F-100F crashed in the same area of desert hills as the Bonanza Air Lines flight.
At both of those rugged, mountainous sites, salvage efforts removed the more accessible and valuable wreckage, but scattered and sometimes substantial portions of the TWA DC-3 and Bonanza Air Lines Fairchild F-27 were left behind, including the DC-3's radial engine
s. The United Airlines DC-7 crash site, however, has been cleared of all but the smallest artifacts, and is threatened by development. In 1958 the site was at least a mile from the nearest paved road; today the spot where the DC-7 hit is adjacent to a developed neighborhood near the intersection of Decatur Boulevard and Cactus Avenue. Five decades after the events of April 21, 1958, a small makeshift marker placed in the sandy soil was the only sign of the loss of United Airlines Flight 736, but preliminary efforts were in motion to encourage public officials to build a permanent memorial to those who died.
}
}
}
}
}
}
- extensive photo gallery (collision angles are inaccurate)
Flight number
A flight number, when combined with the name of the airline and the date, identifies a particular flight. This callsign should not be confused with the tail number of the aircraft, although both can be used as a call-sign as used in general aviation...
operated by United Airlines
United Airlines
United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...
that crashed on April21, 1958. The aircraft assigned to Flight 736, a Douglas DC-7
Douglas DC-7
The Douglas DC-7 is an American transport aircraft built by the Douglas Aircraft Company from 1953 to 1958. It was the last major piston engine powered transport made by Douglas, coming just a few years before the advent of jet aircraft such as the Boeing 707 and Douglas DC-8.-Design and...
airliner carrying 47 persons, was flying at cruise altitude
Cruise (flight)
Cruise is the level portion of aircraft travel where flight is most fuel efficient. It occurs between ascent and descent phases and is usually the majority of a journey. Technically, cruising consists of heading changes only at a constant airspeed and altitude...
above Clark County, Nevada
Clark County, Nevada
-Demographics:As of the census of 2000, there were 1,375,765 people, 512,253 households, and 339,693 families residing within the MSA. The racial makeup of the MSA was 71.6% White , 9.1% Black, 5.7% Asian, 0.8% American Indian and 12.8% of other or mixed race. 22.0% were Hispanic of any race...
, en route to a stopover at Denver, Colorado when it became involved in a mid-air collision
Mid-air collision
A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
with a United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
fighter jet crewed by two pilots. The collision occurred at 8:30 a.m. in clear weather within a major commercial airway
Airway (aviation)
In aviation, an airway is a designated route in the air. Airways are laid out between navigational aids such as VORs, NDBs and Intersections ....
; both aircraft fell out of control from 21000 feet (6,400.8 m) and crashed into unpopulated desert southwest of Las Vegas, Nevada
Las Vegas, Nevada
Las Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...
..
There were no survivors from either aircraft, and with 49 fatalities it remains the deadliest crash in the history of the Las Vegas metropolitan area
Las Vegas metropolitan area
The Las Vegas Valley is the heart of the Las Vegas-Paradise, NV MSA also known as the Las Vegas–Paradise–Henderson MSA which includes all of Clark County, Nevada, and is a metropolitan area in the southern part of the U.S. state of Nevada. The Valley is defined by the Las Vegas Valley landform, a ...
. Among the victims were a group of military personnel and civilian contractors involved with sensitive Department of Defense weapons systems. The loss of the group triggered new rules prohibiting similar groups engaged in critical projects from flying aboard the same aircraft.
The official investigation stated that cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
visibility limitations played a role in the accident, but also faulted military and civilian aviation authorities for not taking measures to reduce well-known collision risks that had existed for over a year within the confines of airways, despite numerous complaints from airline crews. The loss of United Airlines Flight 736—part of a series of 1950s mid-air collisions in American skies, including the well-publicized 1956 Grand Canyon mid-air collision
1956 Grand Canyon mid-air collision
The 1956 Grand Canyon mid-air collision occurred on Saturday, June 30, 1956 at 10:30 AM Pacific Standard Time when a United Airlines passenger airliner struck a Trans World Airlines airliner over the Grand Canyon in Arizona, resulting in the crash of both planes and 128 fatalities...
—helped usher in widespread improvements in air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
within the United States.
Events leading to the accident
Flight 736, a four-engined DC-7 proplinerPropliner
A propliner is a large, propeller-driven airliner. Typically, the term is used for piston-powered airliners that flew before the beginning of the jet age, not for modern turbine-powered propeller airliners...
with aircraft registration
Aircraft registration
An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...
N6328C, departed Los Angeles International Airport
Los Angeles International Airport
Los Angeles International Airport is the primary airport serving the Greater Los Angeles Area, the second-most populated metropolitan area in the United States. It is most often referred to by its IATA airport code LAX, with the letters pronounced individually...
at 7:37 a.m. on a flight to New York City with stops in Denver, Kansas City and Washington, D.C. On board were 42 passengers and five crew members; Captain Duane M. Ward, 44, First Officer Arlin Edward Sommers, 36, Flight Engineer Charles E. Woods, 43, and Stewardesses Pauline Mary Murray, 22, and Yvonne Marie Peterson, 27. Of the passengers on the flight, seven were military personnel and 35 were civilians.
Soon after takeoff the airliner was directed into airway "Victor 8," on a route that took it east over Ontario, California, and then northeast toward Las Vegas. The crew flew the DC-7 under instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
, controlled by Civil Aeronautics Authority (CAA) ground stations, at an authorized altitude of 21000 feet (6,400.8 m) toward the first stopover at Denver.
At 8:14 a.m. the United Airlines crew radioed a routine position report over the Mojave Desert to notify controllers that they expected to arrive over McCarran Field near Las Vegas at 8:31 a.m.
At 7:45 a.m. a U.S. Air Force F-100F-5-NA Super Sabre
F-100 Super Sabre
The North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
jet fighter, serial number
United States military aircraft serials
In the United States, all military aircraft display a serial number to identify individual aircraft. Because these numbers are located on the aircraft tail, they are sometimes referred to unofficially as "tail numbers"...
56-3755, departed Nellis Air Force Base
Nellis Air Force Base
Nellis Air Force Base is a United States Air Force Base, located approximately northeast of Las Vegas, Nevada. It is under the jurisdiction of Air Combat Command .-Overview:...
near Las Vegas on a training flight with two pilots on board. In the front seat of the tandem cockpit was flight instructor
Flight instructor
A flight instructor is a person who teaches others to fly aircraft. Specific privileges granted to holders of a flight instructor qualification vary from country to country, but very generally, a flight instructor serves to enhance or evaluate the knowledge and skill level of an aviator in pursuit...
and safety pilot
Safety pilot
A safety pilot is a certified pilot who scans for other aircraft while another pilot practices instrument approaches or other maneuvers under simulated low visibility conditions while the practicing pilot wears a view limiting device that prevents the pilot from seeing outside the cockpit window...
Capt. Thomas N. Coryell, 29, and behind him sat his student, 1st Lt.
First Lieutenant
First lieutenant is a military rank and, in some forces, an appointment.The rank of lieutenant has different meanings in different military formations , but the majority of cases it is common for it to be sub-divided into a senior and junior rank...
Gerald D. Moran, 24, who as part of his training would spend the flight under a hood that blocked his view outside the aircraft, but allowed him to see his instrument panel.
The instructor had two-way microphone communication with the student, and his duties were to instruct the student in the rear seat, monitor his performance and maintain a lookout for other aircraft. The F-100F had dual pilot control and the instructor could take over flying the jet at any time. The training flight involved a descent and approach
Instrument approach
For aircraft operating under instrument flight rules , an instrument approach or instrument approach procedure is a series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing, or to a point...
to Nellis Air Force Base under simulated instrument meteorological conditions
Instrument meteorological conditions
Instrument meteorological conditions is an aviation flight category that describes weather conditions that require pilots to fly primarily by reference to instruments, and therefore under Instrument Flight Rules , rather than by outside visual references under Visual Flight Rules . Typically, this...
from an altitude of 28000 feet (8,534.4 m). The descent was to be a 'teardrop pattern,' with the Las Vegas commercial radio station KRAM as the navigational fix
Fix (position)
In position fixing navigation, a position fix or simply a fix is a position derived from measuring external reference points.The term is generally used with manual or visual techniques such as the use of intersecting visual or radio position lines rather than the use of more automated and accurate...
, a process that was referred to as the 'KRAM procedure.' The prescribed descent angle for the KRAM procedure was about five degrees.
Pilot Moran radioed the control tower at Nellis Air Force Base at 8:28 a.m. to report that he would now begin a procedural "jet penetration" descent to 14000 feet (4,267.2 m). As the fighter descended, the airliner was approaching Las Vegas air space at about 312 knots on a heading
Heading indicator
The heading indicator is a flight instrument used in an aircraft to inform the pilot of the aircraft's heading. It is sometimes referred to by its older names, the directional gyro or DG, and also direction indicator or DI.- Use :The primary means of establishing the heading in most small...
of 23degrees, flying straight-and-level within the confines of its designated airway. The CAA stations controlling the airliner were unaware of the fighter jet; the Air Force controllers at Nellis Air Force Base directing the jet were unaware of the airliner.
Collision
At 8:30 a.m., despite clear skies with excellent visibility of about 35 miles (56.3 km), the flight paths of the two aircraft intersected about 9 miles (14.5 km) southwest of Las Vegas. The converging aircraft collided nearly head-on at an altitude of 21000 feet (6,400.8 m) at an estimated closure speed of 665 knots.The descending Air Force jet, flying at 444 knots, had clipped the airliner's right wing with its own right wing, immediately sending both aircraft out of control. At the moment of collision the F-100F was in a 90degree bank to the left at a down angle of about 17 degrees. One eyewitness to the collision stated that about two seconds before the collision the wings of the F-100F "dipped"; another eyewitness said the fighter "swooped down" just before the impact. The witness descriptions and the extreme 90 degree bank of the fighter jet—far more than the 30 degrees outlined in the KRAM procedure—suggest an unsuccessful "last second" evasive action on the part of the Air Force crew.
Moments after the two planes collided, the only mayday distress call
Mayday (distress signal)
Mayday is an emergency procedure word used internationally as a distress signal in voice procedure radio communications. It derives from the French venez m'aider, meaning "come help me"....
radioed by the United Airlines crew was heard at 8:30 a.m. plus 20 seconds. The crippled airliner—now missing about eight feet (2.5 m) of its right wing—trailed black smoke and flames as it spiraled earthward, and crashed into a then-empty patch of desert outside the town of Arden
Arden, Nevada
Arden, Nevada is an unincorporated community in Clark County, Nevada. Its ZIP code is 89118. Located about southwest of Las Vegas, the area is experiencing rapid growth in housing development on land formerly owned by the Bureau of Land Management....
. The nearly vertical impact and subsequent explosion instantly killed everyone on board.
The fighter jet—its right wing and right tailplane
Tailplane
A tailplane, also known as horizontal stabilizer , is a small lifting surface located on the tail behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed wing aircraft such as helicopters and gyroplanes...
torn away by the collision—left a trail of fragments as it arced downward, and crashed west of the small community of Sloan
Sloan, Nevada
Sloan is an unincorporated community in Clark County, Nevada.It contains well-preserved petroglyphs and several hiking trails that allow visitors to photograph the petroglyphs...
into a hilly area of uninhabited desert, several miles south of the DC-7 crash site. At least one of the Air Force pilots was still in the jet when it hit the ground, but contemporary news reports differ on whether the other pilot managed an unsuccessful ejection at too low an altitude to survive, or stayed with the jet all the way to the ground.
Witnesses reported seeing a parachute drifting away from the falling F-100F, leading to the hope that a pilot had ejected, but when the parachute was located it was determined to be a drag parachute
Drogue parachute
A drogue parachute is a parachute designed to be deployed from a rapidly moving object in order to slow the object, or to provide control and stability, or as a pilot parachute to deploy a larger parachute...
that is meant to be deployed on landing to help slow the fighter down.
Investigations
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...
sent fingerprint experts to help identify the human remains. The Los Angeles Times
Los Angeles Times
The Los Angeles Times is a daily newspaper published in Los Angeles, California, since 1881. It was the second-largest metropolitan newspaper in circulation in the United States in 2008 and the fourth most widely distributed newspaper in the country....
reported that among the dead were 13 civilian and military managers, engineers and technicians assigned to the American ballistic missile
Ballistic missile
A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...
program. Articles in the Las Vegas Review-Journal
Las Vegas Review-Journal
The Las Vegas Review-Journal is published in Las Vegas, Nevada, United States. It is the largest circulating daily newspaper in Nevada, and one of two daily newspapers in Las Vegas . It is the flagship publication of Stephens Media LLC...
commemorating the 40th and 50th anniversaries of the crash reported that the FBI search went beyond fingerprint matching for identification; the agents were also looking for any surviving sensitive papers relating to national security
National security
National security is the requirement to maintain the survival of the state through the use of economic, diplomacy, power projection and political power. The concept developed mostly in the United States of America after World War II...
that the group of military contractors had carried on board in handcuffed briefcases. The same reports also said the crash prompted the military and defense industry to adopt rules to keep groups of technical people involved in the same critical project from traveling together on the same plane.
The Civil Aeronautics Board (CAB) conducted an investigation and published a report on the accident. The CAB ruled out the weather conditions and the airworthiness
Airworthiness
Airworthiness is a term used to describe whether an aircraft has been certified as suitable for safe flight. Certification is initially conferred by a Certificate of Airworthiness from a National Airworthiness Authority, and is maintained by performing required maintenance actions by a licensed...
of the two planes as factors in the collision. The report stated the probable cause was the high rate of near head-on closure, and that at high altitude, there were human and cockpit limitations involved. Analysis of the approach angles concluded that a metal frame support on the F-100's canopy "interfered seriously" with detection of the DC-7, and a supporting pillar on the DC-7's windshield
Windshield
The windshield or windscreen of an aircraft, car, bus, motorbike or tram is the front window. Modern windshields are generally made of laminated safety glass, a type of treated glass, which consists of two curved sheets of glass with a plastic layer laminated between them for safety, and are glued...
may have hindered sighting the fighter.U.S. Air Force F-100F
|image = United Airlines Flight 736 DC-7 collected debris.jpg|alt=Vertical tail that has torn from the DC-7 lays flat in the foreground. The letters U N I are clearly visible on an intact section. The rudder is mostly missing. A few fragments are placed near where the missing rudder would be. Unidentifiable pieces of wreckage are arrayed in another grouping in the background.
|caption = Some of the Douglas DC-7 aircraft wreckage collected for the crash investigation.
|date = April 21, 1958
|type = Mid-air collision
Mid-air collision
A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
|occurrence_type = Accident
|site = Arden, Nevada
Arden, Nevada
Arden, Nevada is an unincorporated community in Clark County, Nevada. Its ZIP code is 89118. Located about southwest of Las Vegas, the area is experiencing rapid growth in housing development on land formerly owned by the Bureau of Land Management....
, USA
|total_fatalities = 49
|total_survivors = 0
|plane1_type = Douglas DC-7
Douglas DC-7
The Douglas DC-7 is an American transport aircraft built by the Douglas Aircraft Company from 1953 to 1958. It was the last major piston engine powered transport made by Douglas, coming just a few years before the advent of jet aircraft such as the Boeing 707 and Douglas DC-8.-Design and...
|plane1_operator = United Airlines
United Airlines
United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...
|plane1_tailnum =
|plane1_name =
|plane1_origin = Los Angeles, California
|plane1_stopover0 = Denver, Colorado
|plane1_stopover1 = Kansas City, Missouri
|plane1_laststopover = Washington, D.C.
|plane1_destination = New York City
|plane1_passengers = 42
|plane1_crew = 5
|plane1_survivors = 0
|plane2_type = North American F-100F-5-NA Super Sabre
F-100 Super Sabre
The North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
|plane2_operator = United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
|plane2_tailnum = 56-3755
|plane2_image = F-100-356tfs-1960.jpg|alt=Side view of a jet fighter being refueled in flight. The jet has a natural metal finish with large air force lettering and insignia on the fuselage. Two pilots are inside the transparent cockpit canopy. Large streamlined drop tanks hang beneath each wing. A refueling hose is docked with a probe extending from one wing.
|plane2_squadron =
|plane2_name =
|plane2_origin = Nellis Air Force Base, Nevada
Nellis Air Force Base
Nellis Air Force Base is a United States Air Force Base, located approximately northeast of Las Vegas, Nevada. It is under the jurisdiction of Air Combat Command .-Overview:...
|plane2_destination = Nellis Air Force Base
|plane2_passengers =
|plane2_crew = 2
|plane2_survivors = 0
}}
United Airlines Flight 736 was a daily U.S. transcontinental passenger flight
Flight number
A flight number, when combined with the name of the airline and the date, identifies a particular flight. This callsign should not be confused with the tail number of the aircraft, although both can be used as a call-sign as used in general aviation...
operated by United Airlines
United Airlines
United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...
that crashed on April21, 1958. The aircraft assigned to Flight 736, a Douglas DC-7
Douglas DC-7
The Douglas DC-7 is an American transport aircraft built by the Douglas Aircraft Company from 1953 to 1958. It was the last major piston engine powered transport made by Douglas, coming just a few years before the advent of jet aircraft such as the Boeing 707 and Douglas DC-8.-Design and...
airliner carrying 47 persons, was flying at cruise altitude
Cruise (flight)
Cruise is the level portion of aircraft travel where flight is most fuel efficient. It occurs between ascent and descent phases and is usually the majority of a journey. Technically, cruising consists of heading changes only at a constant airspeed and altitude...
above Clark County, Nevada
Clark County, Nevada
-Demographics:As of the census of 2000, there were 1,375,765 people, 512,253 households, and 339,693 families residing within the MSA. The racial makeup of the MSA was 71.6% White , 9.1% Black, 5.7% Asian, 0.8% American Indian and 12.8% of other or mixed race. 22.0% were Hispanic of any race...
, en route to a stopover at Denver, Colorado when it became involved in a mid-air collision
Mid-air collision
A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
with a United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
fighter jet crewed by two pilots. The collision occurred at 8:30 a.m. in clear weather within a major commercial airway
Airway (aviation)
In aviation, an airway is a designated route in the air. Airways are laid out between navigational aids such as VORs, NDBs and Intersections ....
; both aircraft fell out of control from 21000 feet (6,400.8 m) and crashed into unpopulated desert southwest of Las Vegas, Nevada
Las Vegas, Nevada
Las Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...
..
There were no survivors from either aircraft, and with 49 fatalities it remains the deadliest crash in the history of the Las Vegas metropolitan area
Las Vegas metropolitan area
The Las Vegas Valley is the heart of the Las Vegas-Paradise, NV MSA also known as the Las Vegas–Paradise–Henderson MSA which includes all of Clark County, Nevada, and is a metropolitan area in the southern part of the U.S. state of Nevada. The Valley is defined by the Las Vegas Valley landform, a ...
. Among the victims were a group of military personnel and civilian contractors involved with sensitive Department of Defense weapons systems. The loss of the group triggered new rules prohibiting similar groups engaged in critical projects from flying aboard the same aircraft.
The official investigation stated that cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
visibility limitations played a role in the accident, but also faulted military and civilian aviation authorities for not taking measures to reduce well-known collision risks that had existed for over a year within the confines of airways, despite numerous complaints from airline crews. The loss of United Airlines Flight 736—part of a series of 1950s mid-air collisions in American skies, including the well-publicized 1956 Grand Canyon mid-air collision
1956 Grand Canyon mid-air collision
The 1956 Grand Canyon mid-air collision occurred on Saturday, June 30, 1956 at 10:30 AM Pacific Standard Time when a United Airlines passenger airliner struck a Trans World Airlines airliner over the Grand Canyon in Arizona, resulting in the crash of both planes and 128 fatalities...
—helped usher in widespread improvements in air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
within the United States.
Events leading to the accident
Flight 736, a four-engined DC-7 proplinerPropliner
A propliner is a large, propeller-driven airliner. Typically, the term is used for piston-powered airliners that flew before the beginning of the jet age, not for modern turbine-powered propeller airliners...
with aircraft registration
Aircraft registration
An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...
N6328C, departed Los Angeles International Airport
Los Angeles International Airport
Los Angeles International Airport is the primary airport serving the Greater Los Angeles Area, the second-most populated metropolitan area in the United States. It is most often referred to by its IATA airport code LAX, with the letters pronounced individually...
at 7:37 a.m. on a flight to New York City with stops in Denver, Kansas City and Washington, D.C. On board were 42 passengers and five crew members; Captain Duane M. Ward, 44, First Officer Arlin Edward Sommers, 36, Flight Engineer Charles E. Woods, 43, and Stewardesses Pauline Mary Murray, 22, and Yvonne Marie Peterson, 27. Of the passengers on the flight, seven were military personnel and 35 were civilians.
Soon after takeoff the airliner was directed into airway "Victor 8," on a route that took it east over Ontario, California, and then northeast toward Las Vegas. The crew flew the DC-7 under instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
, controlled by Civil Aeronautics Authority (CAA) ground stations, at an authorized altitude of 21000 feet (6,400.8 m) toward the first stopover at Denver.
At 8:14 a.m. the United Airlines crew radioed a routine position report over the Mojave Desert to notify controllers that they expected to arrive over McCarran Field near Las Vegas at 8:31 a.m.
At 7:45 a.m. a U.S. Air Force F-100F-5-NA Super Sabre
F-100 Super Sabre
The North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
jet fighter, serial number
United States military aircraft serials
In the United States, all military aircraft display a serial number to identify individual aircraft. Because these numbers are located on the aircraft tail, they are sometimes referred to unofficially as "tail numbers"...
56-3755, departed Nellis Air Force Base
Nellis Air Force Base
Nellis Air Force Base is a United States Air Force Base, located approximately northeast of Las Vegas, Nevada. It is under the jurisdiction of Air Combat Command .-Overview:...
near Las Vegas on a training flight with two pilots on board. In the front seat of the tandem cockpit was flight instructor
Flight instructor
A flight instructor is a person who teaches others to fly aircraft. Specific privileges granted to holders of a flight instructor qualification vary from country to country, but very generally, a flight instructor serves to enhance or evaluate the knowledge and skill level of an aviator in pursuit...
and safety pilot
Safety pilot
A safety pilot is a certified pilot who scans for other aircraft while another pilot practices instrument approaches or other maneuvers under simulated low visibility conditions while the practicing pilot wears a view limiting device that prevents the pilot from seeing outside the cockpit window...
Capt. Thomas N. Coryell, 29, and behind him sat his student, 1st Lt.
First Lieutenant
First lieutenant is a military rank and, in some forces, an appointment.The rank of lieutenant has different meanings in different military formations , but the majority of cases it is common for it to be sub-divided into a senior and junior rank...
Gerald D. Moran, 24, who as part of his training would spend the flight under a hood that blocked his view outside the aircraft, but allowed him to see his instrument panel.
The instructor had two-way microphone communication with the student, and his duties were to instruct the student in the rear seat, monitor his performance and maintain a lookout for other aircraft. The F-100F had dual pilot control and the instructor could take over flying the jet at any time. The training flight involved a descent and approach
Instrument approach
For aircraft operating under instrument flight rules , an instrument approach or instrument approach procedure is a series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing, or to a point...
to Nellis Air Force Base under simulated instrument meteorological conditions
Instrument meteorological conditions
Instrument meteorological conditions is an aviation flight category that describes weather conditions that require pilots to fly primarily by reference to instruments, and therefore under Instrument Flight Rules , rather than by outside visual references under Visual Flight Rules . Typically, this...
from an altitude of 28000 feet (8,534.4 m). The descent was to be a 'teardrop pattern,' with the Las Vegas commercial radio station KRAM as the navigational fix
Fix (position)
In position fixing navigation, a position fix or simply a fix is a position derived from measuring external reference points.The term is generally used with manual or visual techniques such as the use of intersecting visual or radio position lines rather than the use of more automated and accurate...
, a process that was referred to as the 'KRAM procedure.' The prescribed descent angle for the KRAM procedure was about five degrees.
Pilot Moran radioed the control tower at Nellis Air Force Base at 8:28 a.m. to report that he would now begin a procedural "jet penetration" descent to 14000 feet (4,267.2 m). As the fighter descended, the airliner was approaching Las Vegas air space at about 312 knots on a heading
Heading indicator
The heading indicator is a flight instrument used in an aircraft to inform the pilot of the aircraft's heading. It is sometimes referred to by its older names, the directional gyro or DG, and also direction indicator or DI.- Use :The primary means of establishing the heading in most small...
of 23degrees, flying straight-and-level within the confines of its designated airway. The CAA stations controlling the airliner were unaware of the fighter jet; the Air Force controllers at Nellis Air Force Base directing the jet were unaware of the airliner.
Collision
At 8:30 a.m., despite clear skies with excellent visibility of about 35 miles (56.3 km), the flight paths of the two aircraft intersected about 9 miles (14.5 km) southwest of Las Vegas. The converging aircraft collided nearly head-on at an altitude of 21000 feet (6,400.8 m) at an estimated closure speed of 665 knots.The descending Air Force jet, flying at 444 knots, had clipped the airliner's right wing with its own right wing, immediately sending both aircraft out of control. At the moment of collision the F-100F was in a 90degree bank to the left at a down angle of about 17 degrees. One eyewitness to the collision stated that about two seconds before the collision the wings of the F-100F "dipped"; another eyewitness said the fighter "swooped down" just before the impact. The witness descriptions and the extreme 90 degree bank of the fighter jet—far more than the 30 degrees outlined in the KRAM procedure—suggest an unsuccessful "last second" evasive action on the part of the Air Force crew.
Moments after the two planes collided, the only mayday distress call
Mayday (distress signal)
Mayday is an emergency procedure word used internationally as a distress signal in voice procedure radio communications. It derives from the French venez m'aider, meaning "come help me"....
radioed by the United Airlines crew was heard at 8:30 a.m. plus 20 seconds. The crippled airliner—now missing about eight feet (2.5 m) of its right wing—trailed black smoke and flames as it spiraled earthward, and crashed into a then-empty patch of desert outside the town of Arden
Arden, Nevada
Arden, Nevada is an unincorporated community in Clark County, Nevada. Its ZIP code is 89118. Located about southwest of Las Vegas, the area is experiencing rapid growth in housing development on land formerly owned by the Bureau of Land Management....
. The nearly vertical impact and subsequent explosion instantly killed everyone on board.
The fighter jet—its right wing and right tailplane
Tailplane
A tailplane, also known as horizontal stabilizer , is a small lifting surface located on the tail behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed wing aircraft such as helicopters and gyroplanes...
torn away by the collision—left a trail of fragments as it arced downward, and crashed west of the small community of Sloan
Sloan, Nevada
Sloan is an unincorporated community in Clark County, Nevada.It contains well-preserved petroglyphs and several hiking trails that allow visitors to photograph the petroglyphs...
into a hilly area of uninhabited desert, several miles south of the DC-7 crash site. At least one of the Air Force pilots was still in the jet when it hit the ground, but contemporary news reports differ on whether the other pilot managed an unsuccessful ejection at too low an altitude to survive, or stayed with the jet all the way to the ground.
Witnesses reported seeing a parachute drifting away from the falling F-100F, leading to the hope that a pilot had ejected, but when the parachute was located it was determined to be a drag parachute
Drogue parachute
A drogue parachute is a parachute designed to be deployed from a rapidly moving object in order to slow the object, or to provide control and stability, or as a pilot parachute to deploy a larger parachute...
that is meant to be deployed on landing to help slow the fighter down.
Investigations
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...
sent fingerprint experts to help identify the human remains. The Los Angeles Times
Los Angeles Times
The Los Angeles Times is a daily newspaper published in Los Angeles, California, since 1881. It was the second-largest metropolitan newspaper in circulation in the United States in 2008 and the fourth most widely distributed newspaper in the country....
reported that among the dead were 13 civilian and military managers, engineers and technicians assigned to the American ballistic missile
Ballistic missile
A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...
program. Articles in the Las Vegas Review-Journal
Las Vegas Review-Journal
The Las Vegas Review-Journal is published in Las Vegas, Nevada, United States. It is the largest circulating daily newspaper in Nevada, and one of two daily newspapers in Las Vegas . It is the flagship publication of Stephens Media LLC...
commemorating the 40th and 50th anniversaries of the crash reported that the FBI search went beyond fingerprint matching for identification; the agents were also looking for any surviving sensitive papers relating to national security
National security
National security is the requirement to maintain the survival of the state through the use of economic, diplomacy, power projection and political power. The concept developed mostly in the United States of America after World War II...
that the group of military contractors had carried on board in handcuffed briefcases. The same reports also said the crash prompted the military and defense industry to adopt rules to keep groups of technical people involved in the same critical project from traveling together on the same plane.
The Civil Aeronautics Board (CAB) conducted an investigation and published a report on the accident. The CAB ruled out the weather conditions and the airworthiness
Airworthiness
Airworthiness is a term used to describe whether an aircraft has been certified as suitable for safe flight. Certification is initially conferred by a Certificate of Airworthiness from a National Airworthiness Authority, and is maintained by performing required maintenance actions by a licensed...
of the two planes as factors in the collision. The report stated the probable cause was the high rate of near head-on closure, and that at high altitude, there were human and cockpit limitations involved. Analysis of the approach angles concluded that a metal frame support on the F-100's canopy "interfered seriously" with detection of the DC-7, and a supporting pillar on the DC-7's windshield
Windshield
The windshield or windscreen of an aircraft, car, bus, motorbike or tram is the front window. Modern windshields are generally made of laminated safety glass, a type of treated glass, which consists of two curved sheets of glass with a plastic layer laminated between them for safety, and are glued...
may have hindered sighting the fighter.U.S. Air Force F-100F
|image = United Airlines Flight 736 DC-7 collected debris.jpg|alt=Vertical tail that has torn from the DC-7 lays flat in the foreground. The letters U N I are clearly visible on an intact section. The rudder is mostly missing. A few fragments are placed near where the missing rudder would be. Unidentifiable pieces of wreckage are arrayed in another grouping in the background.
|caption = Some of the Douglas DC-7 aircraft wreckage collected for the crash investigation.
|date = April 21, 1958
|type = Mid-air collision
Mid-air collision
A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
|occurrence_type = Accident
|site = Arden, Nevada
Arden, Nevada
Arden, Nevada is an unincorporated community in Clark County, Nevada. Its ZIP code is 89118. Located about southwest of Las Vegas, the area is experiencing rapid growth in housing development on land formerly owned by the Bureau of Land Management....
, USA
|total_fatalities = 49
|total_survivors = 0
|plane1_type = Douglas DC-7
Douglas DC-7
The Douglas DC-7 is an American transport aircraft built by the Douglas Aircraft Company from 1953 to 1958. It was the last major piston engine powered transport made by Douglas, coming just a few years before the advent of jet aircraft such as the Boeing 707 and Douglas DC-8.-Design and...
|plane1_operator = United Airlines
United Airlines
United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...
|plane1_tailnum =
|plane1_name =
|plane1_origin = Los Angeles, California
|plane1_stopover0 = Denver, Colorado
|plane1_stopover1 = Kansas City, Missouri
|plane1_laststopover = Washington, D.C.
|plane1_destination = New York City
|plane1_passengers = 42
|plane1_crew = 5
|plane1_survivors = 0
|plane2_type = North American F-100F-5-NA Super Sabre
F-100 Super Sabre
The North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
|plane2_operator = United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
|plane2_tailnum = 56-3755
|plane2_image = F-100-356tfs-1960.jpg|alt=Side view of a jet fighter being refueled in flight. The jet has a natural metal finish with large air force lettering and insignia on the fuselage. Two pilots are inside the transparent cockpit canopy. Large streamlined drop tanks hang beneath each wing. A refueling hose is docked with a probe extending from one wing.
|plane2_squadron =
|plane2_name =
|plane2_origin = Nellis Air Force Base, Nevada
Nellis Air Force Base
Nellis Air Force Base is a United States Air Force Base, located approximately northeast of Las Vegas, Nevada. It is under the jurisdiction of Air Combat Command .-Overview:...
|plane2_destination = Nellis Air Force Base
|plane2_passengers =
|plane2_crew = 2
|plane2_survivors = 0
}}
United Airlines Flight 736 was a daily U.S. transcontinental passenger flight
Flight number
A flight number, when combined with the name of the airline and the date, identifies a particular flight. This callsign should not be confused with the tail number of the aircraft, although both can be used as a call-sign as used in general aviation...
operated by United Airlines
United Airlines
United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...
that crashed on April21, 1958. The aircraft assigned to Flight 736, a Douglas DC-7
Douglas DC-7
The Douglas DC-7 is an American transport aircraft built by the Douglas Aircraft Company from 1953 to 1958. It was the last major piston engine powered transport made by Douglas, coming just a few years before the advent of jet aircraft such as the Boeing 707 and Douglas DC-8.-Design and...
airliner carrying 47 persons, was flying at cruise altitude
Cruise (flight)
Cruise is the level portion of aircraft travel where flight is most fuel efficient. It occurs between ascent and descent phases and is usually the majority of a journey. Technically, cruising consists of heading changes only at a constant airspeed and altitude...
above Clark County, Nevada
Clark County, Nevada
-Demographics:As of the census of 2000, there were 1,375,765 people, 512,253 households, and 339,693 families residing within the MSA. The racial makeup of the MSA was 71.6% White , 9.1% Black, 5.7% Asian, 0.8% American Indian and 12.8% of other or mixed race. 22.0% were Hispanic of any race...
, en route to a stopover at Denver, Colorado when it became involved in a mid-air collision
Mid-air collision
A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
with a United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
fighter jet crewed by two pilots. The collision occurred at 8:30 a.m. in clear weather within a major commercial airway
Airway (aviation)
In aviation, an airway is a designated route in the air. Airways are laid out between navigational aids such as VORs, NDBs and Intersections ....
; both aircraft fell out of control from 21000 feet (6,400.8 m) and crashed into unpopulated desert southwest of Las Vegas, Nevada
Las Vegas, Nevada
Las Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...
..
There were no survivors from either aircraft, and with 49 fatalities it remains the deadliest crash in the history of the Las Vegas metropolitan area
Las Vegas metropolitan area
The Las Vegas Valley is the heart of the Las Vegas-Paradise, NV MSA also known as the Las Vegas–Paradise–Henderson MSA which includes all of Clark County, Nevada, and is a metropolitan area in the southern part of the U.S. state of Nevada. The Valley is defined by the Las Vegas Valley landform, a ...
. Among the victims were a group of military personnel and civilian contractors involved with sensitive Department of Defense weapons systems. The loss of the group triggered new rules prohibiting similar groups engaged in critical projects from flying aboard the same aircraft.
The official investigation stated that cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
visibility limitations played a role in the accident, but also faulted military and civilian aviation authorities for not taking measures to reduce well-known collision risks that had existed for over a year within the confines of airways, despite numerous complaints from airline crews. The loss of United Airlines Flight 736—part of a series of 1950s mid-air collisions in American skies, including the well-publicized 1956 Grand Canyon mid-air collision
1956 Grand Canyon mid-air collision
The 1956 Grand Canyon mid-air collision occurred on Saturday, June 30, 1956 at 10:30 AM Pacific Standard Time when a United Airlines passenger airliner struck a Trans World Airlines airliner over the Grand Canyon in Arizona, resulting in the crash of both planes and 128 fatalities...
—helped usher in widespread improvements in air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
within the United States.
Events leading to the accident
Flight 736, a four-engined DC-7 proplinerPropliner
A propliner is a large, propeller-driven airliner. Typically, the term is used for piston-powered airliners that flew before the beginning of the jet age, not for modern turbine-powered propeller airliners...
with aircraft registration
Aircraft registration
An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...
N6328C, departed Los Angeles International Airport
Los Angeles International Airport
Los Angeles International Airport is the primary airport serving the Greater Los Angeles Area, the second-most populated metropolitan area in the United States. It is most often referred to by its IATA airport code LAX, with the letters pronounced individually...
at 7:37 a.m. on a flight to New York City with stops in Denver, Kansas City and Washington, D.C. On board were 42 passengers and five crew members; Captain Duane M. Ward, 44, First Officer Arlin Edward Sommers, 36, Flight Engineer Charles E. Woods, 43, and Stewardesses Pauline Mary Murray, 22, and Yvonne Marie Peterson, 27. Of the passengers on the flight, seven were military personnel and 35 were civilians.
Soon after takeoff the airliner was directed into airway "Victor 8," on a route that took it east over Ontario, California, and then northeast toward Las Vegas. The crew flew the DC-7 under instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
, controlled by Civil Aeronautics Authority (CAA) ground stations, at an authorized altitude of 21000 feet (6,400.8 m) toward the first stopover at Denver.
At 8:14 a.m. the United Airlines crew radioed a routine position report over the Mojave Desert to notify controllers that they expected to arrive over McCarran Field near Las Vegas at 8:31 a.m.
At 7:45 a.m. a U.S. Air Force F-100F-5-NA Super Sabre
F-100 Super Sabre
The North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
jet fighter, serial number
United States military aircraft serials
In the United States, all military aircraft display a serial number to identify individual aircraft. Because these numbers are located on the aircraft tail, they are sometimes referred to unofficially as "tail numbers"...
56-3755, departed Nellis Air Force Base
Nellis Air Force Base
Nellis Air Force Base is a United States Air Force Base, located approximately northeast of Las Vegas, Nevada. It is under the jurisdiction of Air Combat Command .-Overview:...
near Las Vegas on a training flight with two pilots on board. In the front seat of the tandem cockpit was flight instructor
Flight instructor
A flight instructor is a person who teaches others to fly aircraft. Specific privileges granted to holders of a flight instructor qualification vary from country to country, but very generally, a flight instructor serves to enhance or evaluate the knowledge and skill level of an aviator in pursuit...
and safety pilot
Safety pilot
A safety pilot is a certified pilot who scans for other aircraft while another pilot practices instrument approaches or other maneuvers under simulated low visibility conditions while the practicing pilot wears a view limiting device that prevents the pilot from seeing outside the cockpit window...
Capt. Thomas N. Coryell, 29, and behind him sat his student, 1st Lt.
First Lieutenant
First lieutenant is a military rank and, in some forces, an appointment.The rank of lieutenant has different meanings in different military formations , but the majority of cases it is common for it to be sub-divided into a senior and junior rank...
Gerald D. Moran, 24, who as part of his training would spend the flight under a hood that blocked his view outside the aircraft, but allowed him to see his instrument panel.
The instructor had two-way microphone communication with the student, and his duties were to instruct the student in the rear seat, monitor his performance and maintain a lookout for other aircraft. The F-100F had dual pilot control and the instructor could take over flying the jet at any time. The training flight involved a descent and approach
Instrument approach
For aircraft operating under instrument flight rules , an instrument approach or instrument approach procedure is a series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing, or to a point...
to Nellis Air Force Base under simulated instrument meteorological conditions
Instrument meteorological conditions
Instrument meteorological conditions is an aviation flight category that describes weather conditions that require pilots to fly primarily by reference to instruments, and therefore under Instrument Flight Rules , rather than by outside visual references under Visual Flight Rules . Typically, this...
from an altitude of 28000 feet (8,534.4 m). The descent was to be a 'teardrop pattern,' with the Las Vegas commercial radio station KRAM as the navigational fix
Fix (position)
In position fixing navigation, a position fix or simply a fix is a position derived from measuring external reference points.The term is generally used with manual or visual techniques such as the use of intersecting visual or radio position lines rather than the use of more automated and accurate...
, a process that was referred to as the 'KRAM procedure.' The prescribed descent angle for the KRAM procedure was about five degrees.
Pilot Moran radioed the control tower at Nellis Air Force Base at 8:28 a.m. to report that he would now begin a procedural "jet penetration" descent to 14000 feet (4,267.2 m). As the fighter descended, the airliner was approaching Las Vegas air space at about 312 knots on a heading
Heading indicator
The heading indicator is a flight instrument used in an aircraft to inform the pilot of the aircraft's heading. It is sometimes referred to by its older names, the directional gyro or DG, and also direction indicator or DI.- Use :The primary means of establishing the heading in most small...
of 23degrees, flying straight-and-level within the confines of its designated airway. The CAA stations controlling the airliner were unaware of the fighter jet; the Air Force controllers at Nellis Air Force Base directing the jet were unaware of the airliner.
Collision
At 8:30 a.m., despite clear skies with excellent visibility of about 35 miles (56.3 km), the flight paths of the two aircraft intersected about 9 miles (14.5 km) southwest of Las Vegas. The converging aircraft collided nearly head-on at an altitude of 21000 feet (6,400.8 m) at an estimated closure speed of 665 knots.The descending Air Force jet, flying at 444 knots, had clipped the airliner's right wing with its own right wing, immediately sending both aircraft out of control. At the moment of collision the F-100F was in a 90degree bank to the left at a down angle of about 17 degrees. One eyewitness to the collision stated that about two seconds before the collision the wings of the F-100F "dipped"; another eyewitness said the fighter "swooped down" just before the impact. The witness descriptions and the extreme 90 degree bank of the fighter jet—far more than the 30 degrees outlined in the KRAM procedure—suggest an unsuccessful "last second" evasive action on the part of the Air Force crew.
Moments after the two planes collided, the only mayday distress call
Mayday (distress signal)
Mayday is an emergency procedure word used internationally as a distress signal in voice procedure radio communications. It derives from the French venez m'aider, meaning "come help me"....
radioed by the United Airlines crew was heard at 8:30 a.m. plus 20 seconds. The crippled airliner—now missing about eight feet (2.5 m) of its right wing—trailed black smoke and flames as it spiraled earthward, and crashed into a then-empty patch of desert outside the town of Arden
Arden, Nevada
Arden, Nevada is an unincorporated community in Clark County, Nevada. Its ZIP code is 89118. Located about southwest of Las Vegas, the area is experiencing rapid growth in housing development on land formerly owned by the Bureau of Land Management....
. The nearly vertical impact and subsequent explosion instantly killed everyone on board.
The fighter jet—its right wing and right tailplane
Tailplane
A tailplane, also known as horizontal stabilizer , is a small lifting surface located on the tail behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed wing aircraft such as helicopters and gyroplanes...
torn away by the collision—left a trail of fragments as it arced downward, and crashed west of the small community of Sloan
Sloan, Nevada
Sloan is an unincorporated community in Clark County, Nevada.It contains well-preserved petroglyphs and several hiking trails that allow visitors to photograph the petroglyphs...
into a hilly area of uninhabited desert, several miles south of the DC-7 crash site. At least one of the Air Force pilots was still in the jet when it hit the ground, but contemporary news reports differ on whether the other pilot managed an unsuccessful ejection at too low an altitude to survive, or stayed with the jet all the way to the ground.
Witnesses reported seeing a parachute drifting away from the falling F-100F, leading to the hope that a pilot had ejected, but when the parachute was located it was determined to be a drag parachute
Drogue parachute
A drogue parachute is a parachute designed to be deployed from a rapidly moving object in order to slow the object, or to provide control and stability, or as a pilot parachute to deploy a larger parachute...
that is meant to be deployed on landing to help slow the fighter down.
Investigations
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...
sent fingerprint experts to help identify the human remains. The Los Angeles Times
Los Angeles Times
The Los Angeles Times is a daily newspaper published in Los Angeles, California, since 1881. It was the second-largest metropolitan newspaper in circulation in the United States in 2008 and the fourth most widely distributed newspaper in the country....
reported that among the dead were 13 civilian and military managers, engineers and technicians assigned to the American ballistic missile
Ballistic missile
A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...
program. Articles in the Las Vegas Review-Journal
Las Vegas Review-Journal
The Las Vegas Review-Journal is published in Las Vegas, Nevada, United States. It is the largest circulating daily newspaper in Nevada, and one of two daily newspapers in Las Vegas . It is the flagship publication of Stephens Media LLC...
commemorating the 40th and 50th anniversaries of the crash reported that the FBI search went beyond fingerprint matching for identification; the agents were also looking for any surviving sensitive papers relating to national security
National security
National security is the requirement to maintain the survival of the state through the use of economic, diplomacy, power projection and political power. The concept developed mostly in the United States of America after World War II...
that the group of military contractors had carried on board in handcuffed briefcases. The same reports also said the crash prompted the military and defense industry to adopt rules to keep groups of technical people involved in the same critical project from traveling together on the same plane.
The Civil Aeronautics Board (CAB) conducted an investigation and published a report on the accident. The CAB ruled out the weather conditions and the airworthiness
Airworthiness
Airworthiness is a term used to describe whether an aircraft has been certified as suitable for safe flight. Certification is initially conferred by a Certificate of Airworthiness from a National Airworthiness Authority, and is maintained by performing required maintenance actions by a licensed...
of the two planes as factors in the collision. The report stated the probable cause was the high rate of near head-on closure, and that at high altitude, there were human and cockpit limitations involved. Analysis of the approach angles concluded that a metal frame support on the F-100's canopy "interfered seriously" with detection of the DC-7, and a supporting pillar on the DC-7's windshield
Windshield
The windshield or windscreen of an aircraft, car, bus, motorbike or tram is the front window. Modern windshields are generally made of laminated safety glass, a type of treated glass, which consists of two curved sheets of glass with a plastic layer laminated between them for safety, and are glued...
may have hindered sighting the fighter. The CAB accident report also cited a failure of Nellis Air Force Base and the CAA to take measures to reduce a known collision exposure; training exercises were allowed to be conducted for more than a year prior to the collision within the confines of several airways, even after numerous near-misses
Near miss (safety)
See Close Call, for the 2002 film.A near miss is an unplanned event that did not result in injury, illness, or damage – but had the potential to do so. Only a fortunate break in the chain of events prevented an injury, fatality or damage; in other words, a miss that was nonetheless very near...
with military jets had been reported by airline crews.
Legacy
The mid-air collision involving United Airlines Flight 736, and a second one month later over Maryland between a Capital Airlines
Capital Airlines
Capital Airlines was an airline serving the eastern United States that merged into United Airlines in 1961. Its primary hubs were National Airport near Washington, DC, and Allegheny County Airport near Pittsburgh. In the 1950s it was the largest US domestic carrier after the Big Four . Its...
airliner and another military jet, accelerated efforts in the United States to change the way air space was allocated to commercial and military flights.
On April 22, 1958, the day after United Airlines Flight 736 crashed, the CAB proposed an experiment in which it would set aside part of the air space from which would be barred all aircraft lacking specific clearance to enter it. All aircraft operating in the designated space would have to be equipped for instrument flight operations. According to the CAB there had been 159 mid-air collisions in the years 1947-1957, and that in 1957 alone there were 971 near-misses. The increased speed of aircraft and higher air traffic density made it harder to give pilots enough time to spot each other during flights. Therefore, the CAB said, "it is essential that positive control
Positive control
Positive control may refer to:* Positive control group in scientific control* Positive control, the Air traffic control practice of controlling aircraft whose positions are determined by direct radar observation...
be extended to altitudes at 35,000feet and on additional routes as rapidly as practical." At the time such control only existed between 17,000 and 22,000feet on certain transcontinental airways.
In the wake of the two airliners lost in the April and May 1958 collisions, investigators from a House of Representatives committee—concerned about the lack of coordination between civil and military air traffic controllers—imposed a 60-day deadline on the CAB and the Air Force to establish new control procedures. The committee also said that eventually a single civil agency should be given the power to regulate all air space for all types of aircraft. Furthermore, the committee stated that military flying should be controlled in the vicinity of airways not only in instrument weather, but also in visual conditions
Visual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
.
Four months after 49 lives were lost in the worst aviation accident in the history of the Las Vegas region, the Federal Aviation Act of 1958
Federal Aviation Act of 1958
The Federal Aviation Act of 1958 was an act of the United States Congress, , that created the Federal Aviation Agency and abolished its predecessor, the Civil Aeronautics Administration...
was signed into law. The act dissolved the CAA and created the Federal Aviation Agency (FAA, later renamed Federal Aviation Administration
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
). The FAA was given unprecedented and total authority over the control of American air space, including military activity, and as procedures and ATC facilities were modernized, airborne collisions gradually decreased in frequency. The Las Vegas Review-Journal in a 50th anniversary article stated that the act "specifically referenced the crash of United 736 in ordering the creation of the FAA."
The supersonic F-100 left a legacy of many crashes over its years of service; nearly 25 percent were lost to accidents. In particular, 1958 was the most costly, with 47 F-100 pilots killed and 116 of the fighters destroyed, a loss rate averaging almost one every three days.
Legal aftermath
Following the collision at least 31 lawsuitLawsuit
A lawsuit or "suit in law" is a civil action brought in a court of law in which a plaintiff, a party who claims to have incurred loss as a result of a defendant's actions, demands a legal or equitable remedy. The defendant is required to respond to the plaintiff's complaint...
s seeking damages
Damages
In law, damages is an award, typically of money, to be paid to a person as compensation for loss or injury; grammatically, it is a singular noun, not plural.- Compensatory damages :...
were brought against United Airlines, the U.S. Government, or both. On September 24, 1958, United Airlines filed for damages—based on the Federal Tort Claims Act
Federal Tort Claims Act
The Federal Tort Claims Act or "FTCA", , is a statute enacted by the United States Congress in 1948. "Federal Tort Claims Act" was also previously the official short title passed by the Seventy-ninth Congress on August 2, 1946 as Title IV of the Legislative Reorganization Act, 60 Stat...
—against the United States in the U.S. District Court for the District of Delaware. The airline alleged that the United States through its agents in the United States Air Force negligently
Negligence
Negligence is a failure to exercise the care that a reasonably prudent person would exercise in like circumstances. The area of tort law known as negligence involves harm caused by carelessness, not intentional harm.According to Jay M...
operated the F-100F, and sought damages of US$3,576,698. The court found neither crew was negligent for a failure to see and avoid each other, but held the United States was liable because of other negligence. The case was settled on December17, 1962, with the United States agreeing to pay the airline $1.45million.
In another case, on January 8, 1964 surviving relatives of two of the United Airlines crew were awarded a total of $343,200 from the government, with U.S. District Court Judge Hatfield Chilson finding the Air Force pilots did not use "ordinary care" in operation of the fighter jet, and should have yielded the right of way to the DC-7 airliner. Chilson also criticized the Air Force for not coordinating instrument training flights with civilian instrument flight rules traffic, and for failing to schedule flights to minimize traffic congestion. The government appeal
Appeal
An appeal is a petition for review of a case that has been decided by a court of law. The petition is made to a higher court for the purpose of overturning the lower court's decision....
ed, and the relatives cross-appealed to have their damage awards increased, but the earlier 1964 judgment was affirmed on September 30, 1965.
Nearby crash sites
The region where the United Airlines and Air Force aircraft went down has experienced other major airliner crashes. In 1942 movie star Carole LombardCarole Lombard
Carole Lombard was an American actress. She was particularly noted for her comedic roles in the screwball comedies of the 1930s...
and 21 others died in the mountainside crash of TWA Flight 3
TWA Flight 3
TWA Flight 3 was a twin-engine Douglas DC-3-382 propliner, registration NC1946, operated by Transcontinental and Western Air as a scheduled domestic passenger flight from New York, New York, to Burbank, California, via Indianapolis, Indiana; St. Louis, Missouri; Albuquerque, New Mexico and Las...
, about 16 miles (25.7 km) WSW of where United Airlines Flight 736 crashed.
In 1964, 29 people lost their lives when Bonanza Air Lines Flight 114
Bonanza Air Lines Flight 114
Bonanza Air Lines Flight 114 was a Fairchild F-27 turboprop airliner flying out of Phoenix, Arizona to McCarran International Airport in Las Vegas, Nevada, on the evening of November 15, 1964....
flew into a hilltop 5 miles (8 km) SW of the United Airlines impact site; the F-100F crashed in the same area of desert hills as the Bonanza Air Lines flight.
At both of those rugged, mountainous sites, salvage efforts removed the more accessible and valuable wreckage, but scattered and sometimes substantial portions of the TWA DC-3 and Bonanza Air Lines Fairchild F-27 were left behind, including the DC-3's radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
s. The United Airlines DC-7 crash site, however, has been cleared of all but the smallest artifacts, and is threatened by development. In 1958 the site was at least a mile from the nearest paved road; today the spot where the DC-7 hit is adjacent to a developed neighborhood near the intersection of Decatur Boulevard and Cactus Avenue. Five decades after the events of April 21, 1958, a small makeshift marker placed in the sandy soil was the only sign of the loss of United Airlines Flight 736, but preliminary efforts were in motion to encourage public officials to build a permanent memorial to those who died.
See also
- 1958 in aviation1958 in aviationThis is a list of aviation-related events from 1958:- Events :* Gulfstream Aerospace is founded in Savannah, Georgia, in the United States.* The Argentine Navy acquires its first aircraft carrier by purchasing HMS Warrior from the United Kingdom....
- 1958 in the United States1958 in the United States-January–March:* January 8 – 14-year-old Bobby Fischer wins the United States Chess Championship.* January 18 – Armed Lumbee Indians confront a handful of Klansmen in Maxton, North Carolina....
- Aviation accidents and incidentsAviation accidents and incidentsAn aviation accident is defined in the Convention on International Civil Aviation Annex 13 as an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, in which a...
- List of accidents and incidents involving military aircraft (1950–1974) - lists eight U.S. military mid-air collisions in 1958.
- List of accidents and incidents on commercial aircraft
- Mid-air collisionMid-air collisionA mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
- includes a list of other notable mid-air collisions.
External links
- Contemporary newspaper articles selected from the Google News archives:
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- extensive photo gallery (collision angles are inaccurate)