AP 118 · No. 10 Section II · Aircraft Plate 82 / 119

Plate 82 of 119 · Early jet age · Tailless delta research aircraft

Boulton Paul P.111

P.111A, painted as VT935, the Boulton Paul P.111A, the only one built: a single-seat tailless delta research aircraft with a wing swept 45 degrees, powered by a Rolls-Royce Nene turbojet fed from a nose intake, built to Specification E.27/46 to explore the delta wing at transonic speeds, rebuilt after a landing accident as the P.111A with four petal air brakes round the rear fuselage and a long nose probe, and kept by Midland Air Museum at Coventry since 1975; painted as it is shown there: bright yellow overall, a weathered matt-black anti-glare panel over the nose, a black line running from the intake lip through the fuselage roundel and along each upper wing behind the leading edge, a black fin tip, Type D roundels on the fuselage sides and upper wings, a square fin flash and the black serial ‘VT935’ on the tail cone, with a red blank in the intake and another in the jet pipe; it is shown with the intermediate 29 ft 8 in wing tips, which photographs of the airframe suggest but no source confirms, and the underwing markings are left off because no photograph of the underside as displayed was found.

3D model

Turn it over

A procedural model built in Blender from published dimensions, drawings and photographs, painted as VT935, the Boulton Paul P.111A, the only one built: a single-seat tailless delta research aircraft with a wing swept 45 degrees, powered by a Rolls-Royce Nene turbojet fed from a nose intake, built to Specification E.27/46 to explore the delta wing at transonic speeds, rebuilt after a landing accident as the P.111A with four petal air brakes round the rear fuselage and a long nose probe, and kept by Midland Air Museum at Coventry since 1975; painted as it is shown there: bright yellow overall, a weathered matt-black anti-glare panel over the nose, a black line running from the intake lip through the fuselage roundel and along each upper wing behind the leading edge, a black fin tip, Type D roundels on the fuselage sides and upper wings, a square fin flash and the black serial ‘VT935’ on the tail cone, with a red blank in the intake and another in the jet pipe; it is shown with the intermediate 29 ft 8 in wing tips, which photographs of the airframe suggest but no source confirms, and the underwing markings are left off because no photograph of the underside as displayed was found. Drag to orbit, scroll or pinch to zoom · download .glb (697 KB)

Data plate

Specification

First flight, number built and top speed are for the whole family (); engine, crew and dimensions are for the P.111A modelled here.

History

The P.111A

After the war British designers were keen to learn about the delta wing, which German research had suggested might suit flight close to the speed of sound, but almost nothing was known about how a delta handled in practice. The Ministry of Supply ordered a small jet to find out, to Specification E.27/46, and Boulton Paul of Wolverhampton, better known for gun turrets and the Defiant, won the contract. Its P.111 was a stubby tailless delta swept back 45 degrees, with a Rolls-Royce Nene fed through a round nose intake and the pilot sitting high in a small canopy on top. With no tailplane, elevons on the wing trailing edges handled both pitch and roll.

The P.111 first flew on 10 October 1950 at Boscombe Down and then went to the Royal Aircraft Establishment for trials. It could be fitted with three sets of wing tips, giving spans from 25 ft 8 in to 33 ft 6 in, so that the effect of the tip shape could be measured. Its pilots found it extremely sensitive in pitch and roll, and it landed fast. After a wheels-up landing it was rebuilt as the P.111A, which first flew on 2 July 1953 with four petal air brakes round the rear fuselage, a long probe on the nose, revised undercarriage doors and a new bright yellow finish that earned it the nickname “Yellow Peril”. Boulton Paul’s second delta, the P.120, added a tailplane on top of the fin but was lost to flutter in 1952 after only a few weeks of flying.

The P.111A flew from RAE Bedford until 1958, adding to the store of delta-wing knowledge being gathered at the same time by the Avro 707s and Fairey’s research jets for the Vulcan and the delta fighters that followed. It never carried guns and never served with a squadron; its RAF serial and roundels marked it as a government research aircraft. The other half of this gazetteer pairing, the Short SB.5, was a test bed for the wing and low tail of the Lightning, whose wing sweep could be changed on the ground between flights; it survives at the RAF Museum at Cosford.

This airframe

P.111A VT935

VT935The airframe modelled

VT935 was the only P.111 built. It flew first as the P.111 from 1950 and, after its rebuild, as the P.111A from 1953 until it was retired in 1958. It then went to the College of Aeronautics at Cranfield as an instructional airframe, and in July 1975 it came to Midland Air Museum at Coventry, where it is displayed. The model shows it as photographed there: bright yellow overall, a weathered matt-black anti-glare panel over the nose, a black line running from the intake lip through the fuselage roundel and along each upper wing just behind the leading edge, a black fin tip, Type D roundels on the fuselage sides and upper wings, a square fin flash and the serial “VT935” on the tail cone, with red blanks in the intake and jet pipe and the long nose probe passing through the intake blank. It is shown with the intermediate 29 ft 8 in wing tips, which photographs of the airframe suggest but no source confirms. No photograph of the underside as displayed was found, so the underwing markings are left off.

See it at Midland Air Museum

Where to see one

In the gazetteer

The gazetteer records the P.111A in 2 UK collections. The airframe modelled here is marked.

Every airframe and serial All 119 plates

Profiles and models are procedural interpretations built in Blender from published dimensions, three-view drawings and photographs of each airframe. Treat the museum aircraft as the reference.