Hiller X-18 Tilt Roater

The 1950′s was a memorable decade for aviation technology, with the cold war driving the US and Soviet arsenals like never before, experimental aircraft like the Hiller X-18 were granted funds for development.

Design work was started by by Stanley Hiller Jr in 1995 when the Hiller Aircraft Corporation received a contract from the U.S. Air Force.

The X-18 was designed as a cargo transport aircraft and was the first testbed for tiltwing and STOVL (short take off and vertical landing) technology.

Hiller’s X-18 was able to cruise at speeds of up to 253 mph (407 km/h) and measured 63ft in length, 24ft in height and the tri-bladed contra-rotating propellers were a giant 16 ft (4.8 m) across.

In an effort to speed up construction and cut costs, the plane was constructed from scavenged parts including a fuselage from the Chase C-122 Avitruc and turboprops from the Lockheed XFV-1 and Convair XFY-1 Pogo.

The first test flight was recorded on November 24, 1959 however a number of problems plagued the aircraft during its next 19 flights.

The X-18 was susceptible to wind gusts when the wings rotated, the turboprop engines were not linked, so if one engine failed the airplane would crash.

On the 20th July 1961, the X-18 developed problems with the propellers pitch control whilst attempting to hover at 10,000 ft. The aircraft then went into a spin. The crew managed to regained control and fortunately landed with no loss of life, but the X-18 was never to fly again.

Ground testing the X-18′s tiltwing technology still continued, but eventually a test stand the plane had been mounted on failed and the plane was severely damaged in the fall.

The program was then finally canceled on January 18, 1964 and the X-18 was cut up for scrap.

Aircraft Spec’s

• Crew: 2-3
• Length: 63 ft 0 in (19.2 m)
• Wingspan: 48 ft 0 in (14.6 m)
• Height: 24 ft 7 in (7.5 m)
• Empty weight: 26,786 lb (12,150 kg)
• Max takeoff weight: 33,000 lb (14,850 kg)
• Maximum speed: 253 mph (407 km/h)
• Service ceiling 35,300 ft (10,800 m)

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