Today a double feature in our history blog!
1913
US Navy pilot Lt. Patrick Ballenger pilots a US Navy flying boat on this day in aviation history and becomes the first pilot to successfully hand over control of the aircraft in flight to the gyroscopic automatic stabilizing device on his flying boat. You could say the very first Sperry autopilot. Invented by Lawrence B. Sperry. L.W. Sperry in 1928
Besides inventing the autopilot Lawrence Sperry is also credited with inventing the artificial horizon.
1985
72 years after the first flight of an aircraft controlled by a form of autopilot the Bell D-292 ACAP (Advanced Composite Airframe Program) helicopter took flight for the first time.
The Bell D-292 ACAP on its maiden flight
The Bell D-292 was an all-composite
helicopter built by Bell Helicopters Textron under a contract from the US Army as part of the Light Helicopter Experimental program. The aircraft was powered by 2 Avco Lycoming LTS 101-750C-1turboshaft engines, producing 684 hp each. A lot of parts were common to the Bell 222, a short overview:
Engines
Transmission LTS 101-750C Engine
Main rotor
Tail rotor
Tail boom
Vertical fin
Rotor pylon
Three airframes were built for different test purposes;
Tool proofing
Static testing
Flight testing
The use of a composite airframe gave a 22% saving in aircraft weight (with a comparable helicopter) and a 17% saving in cost. The initial test program consisted of 15 hours of ground testing and 50 hours of flight testing, After this initial testing, a military test phase started which was completed in 1988. This military testing consisted of a large number of tests, among others:
Landing Gear crash absorption tests (including dropping the aircraft from 42 feet (~13 meters) and a 50 m/s {97 knots} impact with 10 degrees pitch and 10 degrees roll. All without serious "Injury" to the occupants (crash test dummies)
Lightning protection tests
Repairability test
Interior acoustics testing
Another experiment that the Bell D-292 was used for was the 1986 research by Boeing and US Air Force into the protection of the electric equipment against lightning strikes. With the aid of a 200.000 Ampere / 1.600.000 volt lightning generator, several tests were carried out.
A Bell D-292 airframe during the Boeing & US Air Force static lightning strike tests
Specifications for the Bel D-292 General characteristics
Crew: four
Length: 40 ft 5 in (12.32 m)
Height: 11 ft 2 in (3.40 m)
Empty weight: 5,765 lb (2,615 kg)
Max takeoff weight: 7,485 lb (3,395 kg)
Powerplant: 2 × Avco Lycoming LTS 101-750C-1 turboshaft, 684 hp (510 kW) each
Main rotor diameter: 42 ft 0 in (12.80 m)
Comments