What airliner type, please?

[Chris Scott]

Albatross - DH Gipsy 12 power figures

Quote:
"Courtesy of Flight, June 23rd, 1938:
Maximum power rating: 410/425 bhp at 2400 rpm at 7500 ft, zero boost
Maximum take-off power: 505/525 bhp at 2600 rpm at sea level, 3½ psi boost"

Thanks, Dave, the confusion resulted from my narrow research, limited to the separate Wiki entries for the Albatross and the Gypsy 12. The former gives 525 hp, but the latter states:
"425 hp at 2,450 rpm at 0 psi boost (five minutes maximum)"

Assuming the latter is authentic, perhaps it was a limitation used for T/O at an early stage in development. One can understand the reduced boost, but interesting that the rpm is also limited. I wonder if the crew controlled rpm with a separate "pitch" lever, as is the norm on piston engines with constant-speed props (including the contemporary Twin Wasp). The Gipsy Queen on the post-war, 4-engined Heron had a combined throttle/rpm lever (whereas on the Dove, with its supercharged engines, they were separate, IIRC). If the Gipsy 12 was the same, it might explain the 2450 rpm limit quoted above. If, on the other hand, the pitch (rpm) lever was separate, setting up all four engines at 2450 rpm for T/O would have required careful handling, particularly on bumpy grass airfields.

Quote from Allan Lupton:
"Yes, and for the benefit of those that don't know I'll point out that the cooling air for those air-cooled motors entered through those round intakes on the wing LE, thence flowing forward past the cylinders."

And presumably also to the carburetors? I wonder if the cylinder-head temp control was automatic in the cruise.