Hand-drawn diagram of the 'Goshawk II' front leaf spring with dimensions.
| Identifier | ExFiles\Box 49\3\ Scan080 | |
| Date | 1st February 1922 | |
| X4261 MASTER LEAF IN MAX. BUMP 3.950 RUBBER BUFFER. MAX. BUMP = 2.600 ANGLE OF SPRING 2°-30' SPRING UNDER NORMAL LOAD CAMBER = .150 FRONT SPRING Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II HHS 1/2/22 | ||
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).