Pan Am Flight 526A
Encyclopedia
Pan American World Airways
Flight 526A, a Douglas DC-4
, took off from San Juan-Isla Grande Airport, Puerto Rico
, at 12:11 PM AST
on April 11, 1952 on a flight to Idlewild International Airport, New York City
with 64 passengers and five crew members on board. Due to inadequate maintenance, engine no. 3 failed after takeoff
, followed shortly by engine no. 4.
Nine minutes after takeoff, the aircraft ditched in rough seas 11.3 miles NW
of San Juan Airport, broke apart and sank after three minutes. Panicking passengers refused to leave the sinking wreck. 52 passengers were killed, 17 passengers and crew members were rescued by the USCG.
After this accident it was recommended to implement pre-flight safety demonstrations for over-water flights.
piston aircraft
with four propellers
had made its first flight in 1945 and had 20,835 airframe hours..
1952 on a flight to Idlewild Airport, NY (now known as JFK
). 64 passengers and 5 crew members were on board with Captain John C. Burn, a well-qualified seasoned pilot, in charge.
Just after takeoff engine No. 3
failed at 350 feet and the propeller was feathered (blades were turned parallel to the line of flight to avoid excessive drag
) by the flight crew. The crew decided to return to San Juan Airport, reversed their heading
and managed to continue climbing to 550 feet when engine no. 4 failed, too.
With both engines on the right wing inoperable, the Clipper Endevor was not able to maintain altitude any longer. Captain Burn declared an in-flight emergency and informed the control tower that he planned to attempt a water landing
approximately seven miles NNW
off Isla Grande..
15 knot winds whipped up the sea when the Clipper Endeavor ditched into the Atlantic Ocean north of San Juan at 12:20 PM. The rear fuselage
broke off behind the bulkhead
aft
of the main cabin and the wreck sank in less than three minutes.. Survivors reported later that many passengers had survived the initial ditching but had panicked. They feared the rough seas and the possibility of sharks and had refused to leave the sinking aircraft to board life rafts.
under the command of Lieutenant Ted Rapalus was airborne within 6 minutes.
The USCG's second PBY was undergoing routine maintenance
and had the auxiliary power unit
including bilge pump
removed. Due to the gravity of the emergency the PBY was removed from maintenance status and under the command of Lieutenant Commander Ken Bilderback airborne within 10 minutes.
To assist the rescue on the surface, the USCG buoy tender Bramble
with medical personnel on board was launched as well.
Two SA-16
amphibious aircraft
from the Ramey AFB
located at the far NW corner of Puerto Rico were also dispatched.
Together they were able to rescue twelve passengers and all five crew members from the rough seas.
LCDR Bilderback's PBY had 15 survivors on board when it found itself in a dire situation: because of the missing APU
and bilge pump the flying boat had taken on a lot of sea water and almost no power left to takeoff. The decision was made to transfer the survivors to the Bramble. Sea conditions worsened and after the successful transfer of all but two teenage survivors LCDR Bilderbeck's only options were to either abandon the flying boat or to attempt to taxi
it back on the sea to San Juan Harbor. As they passed Fort El Morro
and taxied into San Juan Harbor, the people lined the shore cheering the rescuers.
In subsequent legal proceedings Captain Burn was exonerated and the fault turned out to be inadequate maintenance and faulty parts.
Pan American World Airways
Pan American World Airways, commonly known as Pan Am, was the principal and largest international air carrier in the United States from 1927 until its collapse on December 4, 1991...
Flight 526A, a Douglas DC-4
Douglas DC-4
The Douglas DC-4 is a four-engined propeller-driven airliner developed by the Douglas Aircraft Company. It served during World War II, in the Berlin Airlift and into the 1960s in a military role...
, took off from San Juan-Isla Grande Airport, Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
, at 12:11 PM AST
UTC-4
UTC−04-00 is an identifier for a time offset from UTC of −04.This offset is used in the Atlantic Standard Time Zone in Canada and the North American Eastern Time Zone during daylight saving time , in the Caribbean region this is considered as the Eastern Caribbean timezone...
on April 11, 1952 on a flight to Idlewild International Airport, New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
with 64 passengers and five crew members on board. Due to inadequate maintenance, engine no. 3 failed after takeoff
Takeoff
Takeoff is the phase of flight in which an aerospace vehicle goes from the ground to flying in the air.For horizontal takeoff aircraft this usually involves starting with a transition from moving along the ground on a runway. For balloons, helicopters and some specialized fixed-wing aircraft , no...
, followed shortly by engine no. 4.
Nine minutes after takeoff, the aircraft ditched in rough seas 11.3 miles NW
Boxing the compass
Boxing the compass is the action of naming all thirty-two points of the compass in clockwise order. Such names are formed by the initials of the cardinal directions and their intermediate ordinal directions, and are very handy to refer to a heading in a general or colloquial fashion, without...
of San Juan Airport, broke apart and sank after three minutes. Panicking passengers refused to leave the sinking wreck. 52 passengers were killed, 17 passengers and crew members were rescued by the USCG.
After this accident it was recommended to implement pre-flight safety demonstrations for over-water flights.
Aircraft
The Douglas DC-4Douglas DC-4
The Douglas DC-4 is a four-engined propeller-driven airliner developed by the Douglas Aircraft Company. It served during World War II, in the Berlin Airlift and into the 1960s in a military role...
piston aircraft
Reciprocating engine
A reciprocating engine, also often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types...
with four propellers
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
had made its first flight in 1945 and had 20,835 airframe hours..
Accident
On a sunny day with a gentle breeze Pan Am Flight 526A, a Douglas DC-4 named Clipper Endeavor took off from San Juan Airport at 12:11 PM on Good FridayGood Friday
Good Friday , is a religious holiday observed primarily by Christians commemorating the crucifixion of Jesus Christ and his death at Calvary. The holiday is observed during Holy Week as part of the Paschal Triduum on the Friday preceding Easter Sunday, and may coincide with the Jewish observance of...
1952 on a flight to Idlewild Airport, NY (now known as JFK
John F. Kennedy International Airport
John F. Kennedy International Airport is an international airport located in the borough of Queens in New York City, about southeast of Lower Manhattan. It is the busiest international air passenger gateway to the United States, handling more international traffic than any other airport in North...
). 64 passengers and 5 crew members were on board with Captain John C. Burn, a well-qualified seasoned pilot, in charge.
Just after takeoff engine No. 3
Aircraft engine position number
Aircraft engine position number is a method to identify the location of engines on multi-engined aircraft. Aircraft engines are numbered from left to right from the view of the pilot looking forward.-Twin-engined aircraft:* #1 - port - on the left...
failed at 350 feet and the propeller was feathered (blades were turned parallel to the line of flight to avoid excessive drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
) by the flight crew. The crew decided to return to San Juan Airport, reversed their heading
Course (navigation)
In navigation, a vehicle's course is the angle that the intended path of the vehicle makes with a fixed reference object . Typically course is measured in degrees from 0° clockwise to 360° in compass convention . Course is customarily expressed in three digits, using preliminary zeros if needed,...
and managed to continue climbing to 550 feet when engine no. 4 failed, too.
With both engines on the right wing inoperable, the Clipper Endevor was not able to maintain altitude any longer. Captain Burn declared an in-flight emergency and informed the control tower that he planned to attempt a water landing
Water landing
A water landing is, in the broadest sense, any landing on a body of water. All waterfowl, those seabirds capable of flight, and some human-built vehicles are capable of landing in water as a matter of course....
approximately seven miles NNW
Boxing the compass
Boxing the compass is the action of naming all thirty-two points of the compass in clockwise order. Such names are formed by the initials of the cardinal directions and their intermediate ordinal directions, and are very handy to refer to a heading in a general or colloquial fashion, without...
off Isla Grande..
15 knot winds whipped up the sea when the Clipper Endeavor ditched into the Atlantic Ocean north of San Juan at 12:20 PM. The rear fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
broke off behind the bulkhead
Rear pressure bulkhead
The aft pressure bulkhead is a component of all large commercial aircraft. It is an airtight bulkhead located between the cabin and the tail of the aircraft. Its purpose is to seal the rear of the plane and thus maintain cabin pressure, and as such it is a vital part of the aircraft.Japan...
aft
Aft
Aft, in naval terminology, is an adjective or adverb meaning, towards the stern of the ship, when the frame of reference is within the ship. Example: "Able Seaman Smith; lay aft!". Or; "What's happening aft?"...
of the main cabin and the wreck sank in less than three minutes.. Survivors reported later that many passengers had survived the initial ditching but had panicked. They feared the rough seas and the possibility of sharks and had refused to leave the sinking aircraft to board life rafts.
Rescue
After having received Captain Burn's emergency transmission, the tower notified the USCG rescue center and a PBY-5A Catalina flying boatFlying boat
A flying boat is a fixed-winged seaplane with a hull, allowing it to land on water. It differs from a float plane as it uses a purpose-designed fuselage which can float, granting the aircraft buoyancy. Flying boats may be stabilized by under-wing floats or by wing-like projections from the fuselage...
under the command of Lieutenant Ted Rapalus was airborne within 6 minutes.
The USCG's second PBY was undergoing routine maintenance
Aircraft maintenance checks
Aircraft maintenance checks are periodic checks that have to be done on all aircraft after a certain amount of time or usage. Airlines and other commercial operators of large or turbine-powered aircraft follow a continuous inspection program approved by the Federal Aviation Administration in the...
and had the auxiliary power unit
Auxiliary power unit
An auxiliary power unit is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft, as well as some large land vehicles.-Function:...
including bilge pump
Bilge pump
A bilge pump is a water pump used to remove bilge water. Since fuel can be present in the bilge, electric bilge pumps are designed to not cause sparks. Electric bilge pumps are often fitted with float switches which turn on the pump when the bilge fills to a set level. Since bilge pumps can fail,...
removed. Due to the gravity of the emergency the PBY was removed from maintenance status and under the command of Lieutenant Commander Ken Bilderback airborne within 10 minutes.
To assist the rescue on the surface, the USCG buoy tender Bramble
USCGC Bramble (WLB-392)
USCGC Bramble is one of the 39 original seagoing buoy tenders built between 1942-1944 for the United States Coast Guard. Bramble is currently a museum ship, part of Port Huron Museum, located in Port Huron, Michigan. She will be closed to the public effective August 14, 2011, owing to a lack of...
with medical personnel on board was launched as well.
Two SA-16
HU-16 Albatross
The Grumman HU-16 Albatross is a large twin-radial engine amphibious flying boat that was utilized by the U.S. Air Force, the U.S. Navy and the U.S. Coast Guard, primarily as a search and rescue and combat search and rescue aircraft...
amphibious aircraft
Amphibious aircraft
An amphibious aircraft or amphibian is an aircraft that can take off and land on either land or water. Fixed-wing amphibious aircraft are seaplanes that are equipped with retractable wheels, at the expense of extra weight and complexity, plus diminished range and fuel economy compared to planes...
from the Ramey AFB
Ramey Air Force Base
Ramey Air Force Base is a former United States Air Force base in Aguadilla, Puerto Rico. In addition to a small on-site Air Force detachment, and occasional operations by the Puerto Rico Air National Guard, a portion of the former Air Force Base is operated by the United States Coast Guard as Coast...
located at the far NW corner of Puerto Rico were also dispatched.
Together they were able to rescue twelve passengers and all five crew members from the rough seas.
LCDR Bilderback's PBY had 15 survivors on board when it found itself in a dire situation: because of the missing APU
Auxiliary power unit
An auxiliary power unit is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft, as well as some large land vehicles.-Function:...
and bilge pump the flying boat had taken on a lot of sea water and almost no power left to takeoff. The decision was made to transfer the survivors to the Bramble. Sea conditions worsened and after the successful transfer of all but two teenage survivors LCDR Bilderbeck's only options were to either abandon the flying boat or to attempt to taxi
Taxiing
Taxiing refers to the movement of an aircraft on the ground, under its own power, in contrast to towing or push-back where the aircraft is moved by a tug...
it back on the sea to San Juan Harbor. As they passed Fort El Morro
Fort San Felipe del Morro
Also known as Fort San Felipe del Morro or Morro Castle, is a 16th-century citadel located in San Juan, Puerto Rico.- Rundown :Lies on the northwestern-most point of the islet of San Juan, Puerto Rico...
and taxied into San Juan Harbor, the people lined the shore cheering the rescuers.
Probable cause
The following causes were found by the investigation:- inadequate maintenance: engine no. 3 was not changed, leading to its failure immediately subsequent to take-off.
- faulty engine parts
- the pilots attempt to re-establish a climb without using all available power after the loss of the second engine (engine no. 4). This led to a nose high pitchFlight dynamicsFlight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
attitude and rapid decrease of airspeedAirspeedAirspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: indicated airspeed , calibrated airspeed , true airspeed , equivalent airspeed and density airspeed....
which settled the aircraft at an altitude too low for an effectual recovery.
In subsequent legal proceedings Captain Burn was exonerated and the fault turned out to be inadequate maintenance and faulty parts.
Aftermath
- After this accident it was recommended to brief the passengers about the location and usage of emergency exits and personal flotation devicePersonal flotation deviceA personal flotation device is a device designed to assist a wearer, either conscious or unconscious, to keep afloat.Devices designed and approved by authorities for use by...
s before flights over open water.
- In memory of the lives lost and honoring the rescuers a San Juan resident wrote a ballad.
- LCDR Bilderback was awarded his second Air MedalAir MedalThe Air Medal is a military decoration of the United States. The award was created in 1942, and is awarded for meritorious achievement while participating in aerial flight.-Criteria:...
. His co-pilot LCDR Jack Natwig received the Silver Lifesaving MedalLifesaving MedalThe Gold Lifesaving Medal and Silver Lifesaving Medal are civil and military decorations of the United States Coast Guard which was first established by Act of Congress, 20 June 1874; later authorized by Title 14 of the United States Code Section 500-501...
for jumping into the sea to successfully rescue a young boy. Air Crew members Bill Pinkston, Jim Tierney, Peter Eustes and Raymond Evans were all commended by the Commandant of the USCG for a job well done..
- Pan Am reused the name Clipper Endeavor for both, a Boeing 707-321B in 1962 and a Boeing 727-235Boeing 727The Boeing 727 is a mid-size, narrow-body, three-engine, T-tailed commercial jet airliner, manufactured by Boeing. The Boeing 727 first flew in 1963, and for over a decade more were built per year than any other jet airliner. When production ended in 1984 a total of 1,832 aircraft had been produced...
in 1980. A Douglas DC-7BDouglas DC-7The 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...
was named Clipper Endeavour.
See also
- Air safetyAir safetyAir safety is a term encompassing the theory, investigation and categorization of flight failures, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.-United...
- Air-sea rescueAir-sea rescueAir-sea rescue is the coordinated search and rescue of the survivors of emergency water landings as well as people who have survived the loss of their sea-going vessel. ASR can involve a wide variety of resources including seaplanes, helicopters, submarines, rescue boats and ships...
- Water landingWater landingA water landing is, in the broadest sense, any landing on a body of water. All waterfowl, those seabirds capable of flight, and some human-built vehicles are capable of landing in water as a matter of course....
- Ethiopian Airlines Flight 961Ethiopian Airlines Flight 961Ethiopian Airlines Flight 961, a Boeing 767-260ER, was hijacked on , en route from Addis Ababa to Nairobi on a Bombay–Addis Ababa–Nairobi–Brazzaville–Lagos–Abidjan service, by three Ethiopians seeking political asylum in Australia. The plane crash-landed in the Indian Ocean near Comoros due to fuel...
- US Airways Flight 1549US Airways Flight 1549US Airways Flight 1549 was US Airways' scheduled domestic commercial passenger flight from LaGuardia Airport in New York City to Charlotte/Douglas International Airport, Charlotte, North Carolina...
- List of accidents and incidents involving commercial aircraft
Sources
- Accident Description Pan Am Flight 526A, Aviation Safety Net
- Accident Description Pan Am Flight 526A, PanAmAir.org
- A Tragic Good Friday 1952, by J. R. Lee, AOC, USCG, Retired and Ted A. Morris, Lt. Col., USAF, Retired