Hewitt-Sperry Automatic Airplane
Encyclopedia
The Hewitt-Sperry Automatic Airplane was a project undertaken during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 to develop an aerial torpedo, also called a flying bomb
Flying bomb
A flying bomb is a manned or unmanned aerial vehicle or aircraft carrying a large explosive warhead, a precursor to contemporary cruise missiles...

 or pilotless aircraft, capable of carrying explosives to its target. It is considered by some to be a precursor of the cruise missile
Cruise missile
A cruise missile is a guided missile that carries an explosive payload and is propelled, usually by a jet engine, towards a land-based or sea-based target. Cruise missiles are designed to deliver a large warhead over long distances with high accuracy...

.

Conceptual development

Before World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, the possibility of using radio to control aircraft intrigued many inventors. One of these, Elmer Sperry, succeeded in arousing the US Navy's interest. Sperry had been perfecting gyroscopes for naval use since 1896 and established the Sperry Gyroscope Company in 1910. In 1911, airplanes had only been flying for eight years, and yet Sperry became intrigued with the concept of applying radio control to them. He realized that for radio control to be effective, automatic stabilization would be essential, so he decided to adapt his naval gyro-stabilizers (which he had developed for destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s).

In 1913, the Navy provided a flying boat
Flying 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...

 to test and evaluate the gyro-based autopilot
Autopilot
An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. An autopilot can refer specifically to aircraft, self-steering gear for boats, or auto guidance of space craft and missiles...

. Sperry's son Lawrence served as an engineer during the test phase. In 1914, Lawrence Sperry was in Europe and observed the developing techniques of aerial warfare, including the use of aircraft. In 1916, the two Sperrys joined Peter Hewitt
Peter Cooper Hewitt
Peter Cooper Hewitt was an American electrical engineer and inventor, who invented the first mercury-vapor lamp in 1901. Hewitt was issued U.S. patent #682692 on September 17, 1901. In 1903, Hewitt created an improved version that possessed higher colour qualities which eventually found widespread...

, an early inventor of radio-related devices, to develop an explosive-laden pilotless airplane.

Elmer Sperry and Hewitt served together on the Naval Consulting Board
Naval Consulting Board
The Naval Consulting Board, also known as the Naval Advisory Board , was a US Navy organization established in 1915 by Secretary of the Navy Josephus Daniels. Daniels created the Board during World War I, but two years before the U.S...

, where they both were members of the Committee on Aeronautics and Aeronautical Motors. Because of these connections, they were able to arrange for a representative of the Navy's Bureau of Ordnance
Bureau of Ordnance
The Bureau of Ordnance was the U.S. Navy's organization responsible for the procurement, storage, and deployment of all naval ordnance, between the years 1862 and 1959.-History:...

, Lt. T. S. Wilkinson, to examine the control equipment they assembled. The system consisted of a gyroscopic stabilizer, a directive gyroscope, an aneroid barometer to regulate height, servo-motors for control of rudders and ailerons, and a device for distance gearing. These all could be installed in an airplane which could be catapulted or flown from the water, and would climb to a predetermined altitude, fly a pre-set course, and after traveling a pre-set distance, drop its bombs or dive to the ground. Wilkinson reported that the weapon did not possess a degree of accuracy sufficient to hit a ship, but, because of its range of 50 to 100 miles (160.9 km), it might be of interest to the Army.

Construction begins

However, after the US declaration of war
Declaration of war
A declaration of war is a formal act by which one nation goes to war against another. The declaration is a performative speech act by an authorized party of a national government in order to create a state of war between two or more states.The legality of who is competent to declare war varies...

 on Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, Sperry began urging the navy to revisit the idea. The Naval Consulting Board supported him, and formally requested the Secretary of Navy to apportion $50,000 for the work. The government thus included the development of the flying bomb or aerial torpedo in its war preparations. The Senate went so far as to establish two classes for the type weapon, one for wireless control, the other for completely automatic operation. Final approval came on May 17, 1917, and the Navy agreed to provide five (later upped to seven) Curtiss
Curtiss Aeroplane and Motor Company
Curtiss Aeroplane and Motor Company was an American aircraft manufacturer that went public in 1916 with Glenn Hammond Curtiss as president. Throughout the 1920s and 1930s, the company was the largest aircraft manufacturer in the United States...

 N-9 seaplanes and to purchase six sets of the Sperry automatic control gear. Navy Secretary Josephus Daniels
Josephus Daniels
Josephus Daniels was a newspaper editor and publisher from North Carolina who was appointed by United States President Woodrow Wilson to serve as Secretary of the Navy during World War I...

 agreed to spend $200,000 on the project, with the money to be administered by the Bureau of Ordnance
Bureau of Ordnance
The Bureau of Ordnance was the U.S. Navy's organization responsible for the procurement, storage, and deployment of all naval ordnance, between the years 1862 and 1959.-History:...

, the Bureau of Construction and Repair
Bureau of Construction and Repair
The Bureau of Construction and Repair was the part of the United States Navy which from 1862 to 1940 was responsible for supervising the design, construction, conversion, procurement, maintenance, and repair of ships and other craft for the Navy...

 and the Bureau of Engineering. The operation was established at Copiague, Long Island
Long Island
Long Island is an island located in the southeast part of the U.S. state of New York, just east of Manhattan. Stretching northeast into the Atlantic Ocean, Long Island contains four counties, two of which are boroughs of New York City , and two of which are mainly suburban...

.

The autopilot equipment was already designed, but the radio control system hadn't been fully developed, so while the hangars were being built at Copiague, Sperry turned his attention to this aspect, purchasing rights to a number of patented radio-related inventions. Ultimately, though, the radio control systems were not used on the Hewitt-Sperry Automatic Airplane. Later, in 1922, the system was installed on several Verville
Alfred V. Verville
Alfred Victor Verville was an aviation pioneer and designer who contributed to civilian and military aviation. During his 47 years in the aviation industry, he led the design and development of nearly a dozen commercial and military airplanes...

-designed planes along with gear for the Army Air Services engineering division. These aircraft successfully hit their targets from ranges of 30, 60 and 90 miles (144.8 km).

Flight test

The first test flights of an autopilot-equipped aircraft was in September, 1917, and took place with a human pilot onboard to fly the takeoff. By November, the system successfully flew the aircraft to its intended target at a 30 miles (48.3 km) range, where the distance-measuring gear would drop a bag of sand. Accuracy was within two miles (3 km) of target.

Having observed the test flights, Rear Admiral
Rear Admiral
Rear admiral is a naval commissioned officer rank above that of a commodore and captain, and below that of a vice admiral. It is generally regarded as the lowest of the "admiral" ranks, which are also sometimes referred to as "flag officers" or "flag ranks"...

 Ralph Earle
Ralph Earle (American naval officer)
Ralph Earle served the United States Navy during the Spanish-American War and World War I. He was the Chief, Bureau of Ordnance and retired as a rear admiral in 1927.-Early years:...

 proposed a program to eliminate the German U-boat
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

 threat, one element of which was to use flying bombs, launched from Navy ships, to attack the submarine bases at Wilhelmshaven
Wilhelmshaven
Wilhelmshaven is a coastal town in Lower Saxony, Germany. It is situated on the western side of the Jade Bight, a bay of the North Sea.-History:...

, Cuxhaven and Heligoland
Heligoland
Heligoland is a small German archipelago in the North Sea.Formerly Danish and British possessions, the islands are located in the Heligoland Bight in the south-eastern corner of the North Sea...

. Ultimately this plan was rejected, but had an element of prophecy, for in September 1944, during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, a modified B-24 flying as a drone attacked the submarine installations at Helgoland. Not only was Earle's recommendation rejected, but the Navy declared that though development of the system was to continue, no production resources were to be diverted to it, and it was not to go into production.

Curtiss-Sperry Flying Bomb

When the N-9 flight test program got started, it became apparent that a more efficient airframe
Airframe
The airframe of an aircraft is its mechanical structure. It is typically considered to include fuselage, wings and undercarriage and exclude the propulsion system...

 was needed. Because war production deliveries could not be diverted, a special, rush order was placed with Curtiss in October, 1917, for six planes of unique design, with an empty weight of 500 lb (226.8 kg), top speed of 90 mi/h, range of 50 miles (80.5 km) and the capability of carrying up to 1000 lb (453.6 kg) of explosives. They became known as the Curtis-Sperry Flying Bomb. Because this was to be a design dedicated to the remote control concept, the planes were not equipped with seats or standard pilot controls. No flight or wind-tunnel testing of the design was performed before production began. The first was delivered on November 10.

One of the most daunting challenges to the designers was the launch mechanism. The original concept envisioned by Hewitt and Sperry was a catapult mechanism or from the water (the N-9s were seaplanes, the Flying Bomb was not). For the Flying Bomb, it was decided to try to launch it by sliding it down a long wire. In November and December 1917, three attempts were made to launch the Flying Bomb. On the first launch, one wing was damaged as the plane went down the wire, and on the second, the plane lifted from the wire but immediately plunged to the ground. The wire method was then abandoned in favor of a traditional catapult with a 150 feet (45.7 m) track, with power obtained from a 3-ton weight being dropped from a height of 30 feet (9.1 m). On the third try, the plane lagged behind the cart, damaging the propeller, and the plane flipped over its nose. Two more attempts in January, 1918, saw the plane get airborne, but it was too tail-heavy, so it stalled and crashed almost immediately.

It was realized that some flight test evaluation of the aircraft's capabilities was necessary. One of the planes was then fitted out with sled runners for landing gear, a seat and standard control stick, and Lawrence Sperry decided that he would be the test pilot
Test pilot
A test pilot is an aviator who flies new and modified aircraft in specific maneuvers, known as flight test techniques or FTTs, allowing the results to be measured and the design to be evaluated....

. While taxiing it on ice, he hit some slushy snow, and wrecked the plane, though Sperry was unhurt. A second airplane was fitted out, and Sperry managed to get it in the air, but lost control when the automatic pilot was engaged. After two complete rolls, Sperry managed to regain control and land safely.

Clearly, though, more attention to flight testing the basic design was needed, particularly in the area of handling qualities
Handling qualities
Handling qualities is one of the two principal regimes in the science of flight test . Handling qualities involves the study and evaluation of the stability and control characteristics of an aircraft...

. Sperry and his assistant, N. W. Dalton, obtained a Marmon automobile, and mounted the Curtiss-Sperry Flying Bomb to the top of it. In this configuration, Sperry and his crew drove the Long Island Motor Parkway
Long Island Motor Parkway
The Long Island Motor Parkway , also known as the Vanderbilt Parkway and Motor Parkway, was the first roadway designed for automobile use only. It was privately built by William Kissam Vanderbilt with overpasses and bridges to remove intersections...

 at 80 mi/h, one of the first examples of an open-air wind tunnel, and adjusted the flight controls to what they thought was the optimum settings. The design of the fuselage was changed slightly, lengthening it by two feet.

The Marmon was not only an excellent way to adjust the flight controls, it was realized that it would also be a good launching platform, and this was tried on March 6, 1918. The aircraft left the car cleanly, and flew in stable flight for the 1000 yards (914.4 m) that the distance-measuring gear had been set for. For the first time in history, an unmanned, heavier-than-air vehicle had flown in controlled flight.

The feat, however, could not be duplicated, and it was thought that the roadway was too rough. The Marmon was fitted with railroad wheels, and an unused spur of the Long Island Rail Road
Long Island Rail Road
The Long Island Rail Road or LIRR is a commuter rail system serving the length of Long Island, New York. It is the busiest commuter railroad in North America, serving about 81.5 million passengers each year. Established in 1834 and having operated continuously since then, it is the oldest US...

, four miles (6 km) east of Farmingdale, New York
Farmingdale, New York
The Village of Farmingdale is an incorporated village on Long Island within the Town of Oyster Bay in Nassau County, New York in the United States...

 was put back into service. On the first try, before full flying speed had been reached, the aircraft developed enough lift to raise the front wheels off the track, and another crash resulted. It was time to re-think the catapult system, and to help design it, Sperry and Hewitt hired a young and promising engineer named Carl Norden
Carl Norden
Carl Lucas Norden , born Carel Lucas van Norden, was an American engineer widely known for having invented the Norden bombsight....

. The first try with the new system was in August, 1918, and it too resulted in a crash. Two more tests were tried, with the stabilization package that had been design for the Flying Bomb replaced with the four-gyro system used earlier on the N-9 tests, but the result was again a disappointment, with very short flights ending in crashes. On the last one, on September 26, the Flying Bomb climbed straight for about a hundred yards, then entered a spiral dive and crashed. This was the final flight for the Curtiss-Sperry Flying Bomb, as all the usable airframes had been consumed in crashes, and there remained no confidence in the design. Sperry and Hewitt returned to the N-9.

Return of the N-9

The Sperrys built a wind tunnel at the Washington Navy Yard
Washington Navy Yard
The Washington Navy Yard is the former shipyard and ordnance plant of the United States Navy in Southeast Washington, D.C. It is the oldest shore establishment of the U.S. Navy...

 and carried out a series of tests on the N-9, fine tuning the design. On October 17, an unmanned N-9 was launched using the new Norden catapult system. It came cleanly off the track, climbed steadily and flew within 2° of the line of intended flight. The distance gear had been set for a flight of eight miles (13 km), but somehow malfunctioned. When last seen, the N-9 was cruising over Bayshore Air Station at about 4000 feet (1,219.2 m), heading east. It was never seen again.

Despite the success of the stabilization gear, there was doubt in the Navy about the program, and they asked Carl Norden
Carl Norden
Carl Lucas Norden , born Carel Lucas van Norden, was an American engineer widely known for having invented the Norden bombsight....

 to review the Sperry components and recommend improvement. The navy was, by now, satisfied with the concept, and was contemplating purchasing such equipment on its own, apart from the Sperrys. Elmer Sperry tried to stir up enthusiasm again, calling the concept of the flying bomb the "gun of the future". This was to no avail, however. World War I came to a close when the Armistice
Armistice
An armistice is a situation in a war where the warring parties agree to stop fighting. It is not necessarily the end of a war, but may be just a cessation of hostilities while an attempt is made to negotiate a lasting peace...

 was signed on November 11, 1918. Almost a hundred flights had been flown in the N-9, but almost all of these were in the N-9s and had a 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...

 onboard. The Navy took complete control of the program from Sperry, spelling the end of the Hewitt-Sperry Automatic Airplane.

Follow on programs

During the early post-war years, the Navy sponsored similar projects. For the first program, Witteman-Lewis aircraft and Norden-designed gyrostabilizers were used, but the results were no better than those achieved by the Sperrys. In 1921, the program was reoriented to focus on the radio control aspect. The control equipment was developed at the radio laboratory at NAS Anacostia (later the Naval Research Laboratory
United States Naval Research Laboratory
The United States Naval Research Laboratory is the corporate research laboratory for the United States Navy and the United States Marine Corps and conducts a program of scientific research and development. NRL opened in 1923 at the instigation of Thomas Edison...

). In 1923, tests began, and were relatively successful, but interest waned and the project lapsed in 1925. Over a decade was to pass before the Navy seriously undertook the development of target drones and pilotless aircraft.
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