In 1920, the British Aviation Ministry published specification 4/20 for a medium bomber. This specification was based on a proposal by John North, designer at Boulton and Paul Ltd., for the construction of an all-metal bomber. Consequently, on July 7, 1920, Boulton and Paul signed a contract with the Aviation Ministry for the construction of a prototype bomber, designated Boulton-Paul P.15 Bolton.
Design and Specifications
During the development of the new bomber, John North utilized insights from his earlier P.7 Bourges bomber. The Boulton was a three-seater, all-metal, three-bay biplane, equipped with two Napier Lion II engines, each producing 450 hp. The aircraft’s defensive armament consisted of two 7.7-mm Lewis machine guns on movable Scarff-type turrets, located in the nose and mid-upper fuselage. Its bomb load comprised four 104-kg bombs.
Testing and Development
The Bolton prototype (J6584) first flew in November 1922, and a month later, it was sent to the Martlesham Heath center for final trials. During these trials, a number of complaints were raised regarding the aircraft’s design, leading to the P.15’s return to the factory in June 1923. After modifications lasting almost a year, the aircraft returned to the A & AEE in May 1924, where it was used for various experiments for another year.
Technical Specifications
| Modification | P. 15 |
| Wingspan, m | 19.06 |
| Length, m | 15.85 |
| Height, m | 4.40 |
| Wing area, m2 | 84.00 |
| Normal takeoff weight, kg | 4313 |
| Engine type | 2 Piston engine Napier Lion II |
| Power, hp | 2 x 450 |
| Maximum speed, km/h | 190 |
| Cruising speed, km/h | 165 |
| Crew | 3 |
| Armament | two 7.7-mm Lewis machine guns, 4 x 104-kg bombs |
Image and diagram gallery of the Boulton-Paul P.15 Bolton
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