Hewitt-Sperry Automatic Airplane - sperryatorpedo1918.jpg ...

https://en.wikipedia.org/wiki/Hewitt...matic_Airplane

The Hewitt-Sperry Automatic Airplane was a project undertaken during World War I
to develop an aerial torpedo, also called a flying bomb or pilotless aircraft,
capable of carrying explosives to its target. It is considered by some to be a
precursor of the cruise missile.

Before World War I, 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 destroyers).

In 1913, the Navy provided a flying boat to test and evaluate the gyro-based
autopilot. 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, 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, 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, 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 km),
it might be of interest to the Army.

However, after the US declaration of war on Germany, 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 N-9 seaplanes and to purchase six sets of
the Sperry automatic control gear. Navy Secretary Josephus Daniels agreed to
spend $200,000 on the project, with the money to be administered by the Bureau
of Ordnance, the Bureau of Construction and Repair and the Bureau of
Engineering. The operation was established at Copiague, Long Island.

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-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 (140 km).


Role
Missile

National origin
United States

Designer
Elmer Sperry
Peter Cooper Hewitt

First flight
September 1917

Status
Development discontinued

Primary user
United States Navy

Number built
7 Curtiss Model N-based prototypes
6 Curtiss-Sperry Flying Bomb prototypes

Developed from
Curtiss Model N

The first test flights of an autopilot-equipped aircraft was in September, 1917,
and took place with a human pilot on board to fly the takeoff. By November, the
system successfully flew the aircraft to its intended target at a 30-mile (48
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 Ralph Earle proposed a program to
eliminate the German U-boat threat, one element of which was to use flying
bombs, launched from Navy ships, to attack the submarine bases at Wilhelmshaven,
Cuxhaven and Heligoland. Ultimately this plan was rejected, but had an element
of prophecy, for in September 1944, during World War II, a modified B-24 flying
as a drone attacked the submarine installations at Heligoland. 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.

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-foot (46 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. 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. 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 at 80 mph (130 km/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 fitted with railroad wheels, and an unused spur of the Long
Island Rail Road, four miles (6 km) east of Farmingdale, New York 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. 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.





*