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).
Aircraft engine performance, comparing with German planes and detailing improvements to the D.H.4 aircraft.
| Identifier | Morton\M21\ img015 | |
| Date | 1st July 1917 | |
| [Typed Text] To EH. from R.{Sir Henry Royce} 2. 250 - 270 HP this engine will give. As I have written to Lord Herbert Scott, I believe that the Germans are using a larger plane for the weight of their equipment and the horse.power of their engines. Consequently, they will probably be able to climb higher than we can, with a smaller proportionate wing area. At moderate heights, however, our machines will probably be faster, but I doubt if this is a real advantage compared with the rate and height of climb, and ease of getting off the ground and landing. [Handwritten Annotations] (In left margin, next to 'landing.'): obtained by relatively larger wing area (In right margin): See Mr Plattford re a more efficient propeller they are using on the DH{D. Henderson - Showroom}4 at the front ask him to let them know of. There is anything special about the type & size of R.{Sir Henry Royce} If you think this left memo would interest Mr Walker send him a copy. (Circled): V First seen 22/8/17 [Handwritten Text] I have heard from two separate sources of improvements effected in the climb (at higher altitudes) of D.H.4 with our 2-275 Eagles, when fitted with "Tibbenham" propellers. I am also informed that they are made to the same drawings as the standard props for this engine. (4 bladed) Reliable information re props is not very easily obtained, but I hope to report more information shortly. D.H.4 have the reputation of being very good at the front for high altitude work. (2-275 Eagles); can maintain a cruise about at 22,000 ft. Successful scouting & photographic work is now being done at this altitude (for instance). EP{G. Eric Platford - Chief Quality Engineer} | ||