Boulton Paul P. 111
| Boulton Paul P. 111 | |
|---|---|
 Boulton Paul P. 111 |
|
| Type: | Experimental airplane |
| Design country: | |
| Manufacturer: | |
| First flight: |
October 10, 1950 |
| Number of pieces: |
1 |
The Boulton Paul P.111 was a British test aircraft that was built in the 1950s for research into the aerodynamics of tailless delta wing aircraft.
construction and development
In the late 1940s and early 1950s, the Allied aviation industry pursued various projects to research the design ideas from Nazi Germany at the end of World War II . As part of this activity, Boulton Paul Aircraft Ltd built the P.111 for specification E.27 / 46 of the Ministry of Aviation . The project was intended to examine the concept of delta wing shape. The P.111 was designed as a compact airframe with a Rolls-Royce Nene engine, a Martin-Baker ejection seat and delta wings. The wings had a 45 ° sweep. Without wingtip extensions, the wing was trimmed at about 75% of the full delta. The aircraft could be flown with these wings or one of two pairs of different extensions. With the larger extensions, the wings were given an almost perfect pointed delta shape. These extensions allowed an investigation of the aerodynamic effects of the wing tip shapes of delta wings. In contrast to the Avro 707 , rolling and elevation changes were controlled by a pair of ailerons. The vertical tail had an unearthed trailing edge and the tail could be removed and changed. Apparently this was not done, however, the P.111 always flew with the sharp tip. The P.111 was one of the first aircraft to have a fully hydraulically operated control system equipped with electric trim tabs. Because the Nene engine had a radial compressor , the P.111 had a convex fuselage with an oval air inlet at the bow. The inwardly retracting landing gear had a noticeably wide track and a long nose wheel leg which, when standing on the ground, resulted in an angle of attack of 17 °. The construction was made of all metal with the exception of the wing extensions and the rib tip, which were made of fiberglass-reinforced plastic .
history
The P.111 made its first flight on October 10, 1950 at the Royal Aircraft Establishment at Boscombe Down. The pilot was Squadron Leader Bob Smyth. On later test flights, test pilot Alexander E. "Ben" Gunn sat at the controls, who described the aircraft as "sensitive" and "like flying a razor blade". One problem was that the servo control was without any feedback at speeds above 450 mph, so the pilot could not feel the forces on his controls. There was also a shift in the center of gravity when the landing gear was extended or retracted. Landing speed was fast because of the lack of air brakes and also because of the need to maintain the engine speed to keep the generators running, which generated electricity for the electrically operated control surfaces. During the first few months the controls were spring loaded to give the appearance of back pressure and the rudder was changed to manual control. The P.111 initially had a windshield that was blown from one piece and continuously curved, which was later replaced by a conventional cockpit hood with a flat windshield. After a landing accident in which the landing gear was not extended, the P.111 was modified during the repair work to improve flight characteristics and was re-designated as P.111A. Four airbrakes were built into the fuselage to provide lower landing speeds and the landing gear flaps were modified to reduce the change in center of gravity. A long pitot tube was installed. The most noticeable change was the new bright yellow overall paint, because before the P.111 was unpainted or silver. The P.111A soon bore the nickname “ Yellow Peril ”.
The P.111A first flew at Boscombe Down on July 2, 1953 . Shortly afterwards, the anti-spin parachute, which had been mounted on the back of the rear fuselage, was reinforced so that it could be used as a braking parachute. After a modification, the pilot was also able to regulate the power of the spreader reinforcement systems himself. The P.111 was used for a series of studies of the properties of delta wings in Bedford at the Royal Aircraft Establishment . During this time it flew with each of the three wingtips. After a last flight in 1958, the P.111 came to the Cranfield College of Aeronautics as an instruction booth . In 1975 it was acquired by the Midland Aircraft Preservation Society on long-term loan to its Midland Air Museum at Coventry Airport. The P.111 has been on display in the static exhibition since Sunday, July 13, 1975 since it was transported there by road.
The P.111 was followed by another experimental aircraft with delta wings, the P.120 , which, apart from an additional horizontal stabilizer, was largely identical to the P.111.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 1 |
| length | (without nasogastric tube) 7.95 m |
| span | (with removable wing tips) 7.82 m, 9.07 m and 10.21 m |
| height | 3.81 m |
| Wing area | (with removable wing tips) 25.01 m², 26.40 m² and 26.94 m² |
| Profile thickness | 10% |
| Empty mass | 3,410 kg |
| Takeoff mass | 4,595 kg |
| Engine | 1 × Rolls-Royce Nene R3N2 Turbojet, 22.69 kN |
| Top speed | at sea level 1,045 km / h |
| Service ceiling | 10,670 m |
| Rate of climb | 48 m / s |
See also
Aircraft of comparable role, configuration and time
literature
- Alec Brew: Boulton Paul Aircraft since 1915. Putnam, London 1993, ISBN 0-85177-860-7 .
- Barry Jones: Boulton Paul's Dicey Deltas. In: Airplane Monthly. Volume 21, No. 2, 1993, pp. 34-41.
- Barry Jones: British Experimental Turbojet Aircraft. Crowood, London 2007, ISBN 978-1-86126-860-0 .
Web links
Individual evidence
- ↑ Barry Jones: Boulton Paul's Dicey Deltas. In: Airplane Monthly. Volume 21, No. 2, 1993, pp. 34-41, here: 34.
- ↑ a b c d Alec Brew: Boulton Paul Aircraft since 1915. Putnam, London 1993, ISBN 0-85177-860-7 , pp. 293-301.
- ↑ Barry Jones: Boulton Paul's Dicey Deltas. In: Airplane Monthly. Volume 21, No. 2, 1993, pp. 34-41, here: 38.
- ↑ Barry Jones: Boulton Paul's Dicey Deltas. In: Airplane Monthly. Volume 21, No. 2, 1993, pp. 34-41, here: 39.
- ^ Midland Air Museum . Retrieved March 16, 2007.