Initial Design and Development
The Cobham medium bomber was the only twin-engine aircraft built by the Sopwith company. Developed during the summer of 1918 under Air Ministry Specification IV (also considering the requirements of subsequent Specifications VI and VIII), the bomber was a three-seater triplane. It was equipped with two 320 hp ABC Dragonfly I engines and capable of carrying up to three 113-kg bombs, placed vertically in the middle of the fuselage.
First Flight and Variants
The first of the ordered machines (H671) was ready in December 1918, but due to problems with engine supply, its first flight was postponed several times. Finally, the aircraft’s designer, Herbert Smith, decided to take a drastic step: replace the engines with less powerful Siddeley Puma units (240 hp). In this variant, designated Cobham Mk.II, the aircraft first took to the air in April 1919.
In March of the following year, the Cobham Mk.II was sent for trials to the Martlesham Heath center, and then in November, it was transferred to the RAE in Farnborough, where it continued to fly until January 27, 1921. The two other Cobhams (H672 and H673) were only completed by 1920. They received 360 hp ABC Dragonfly IA engines and were designated Cobham Mk.I. Their first flights took place in January and February 1920, respectively.
The End of an Ambitious Project
By this time, the Sopwith company was experiencing serious financial difficulties, and both aircraft were handed over to the Air Ministry for further work. During the following year, the aircraft underwent a series of tests and modifications. However, a decision was made to completely cease work on the project, marking the end of the Cobham.
Technical Specifications
| Modification | Cobham Mk.I |
| Wingspan, m | 16.46 |
| Length, m | 11.58 |
| Height, m | 3.96 |
| Engine type | 1 Piston engine ABC Dragonfly IA |
| Power, hp | 1 x 360 |
| Crew | 3 crew members |
| Armament | two 7.7-mm Lewis machine guns (one in the nose and one in the mid-fuselage section); 3 x 113-kg bombs |
Image and diagram gallery of the Sopwith Cobham
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