An engineer working on one of Air Atlantique’s DC-6 Double Wasp engines.

Самолёты на фотографии: Aircrafts on the photo: Douglas DC-6 / C-118 Liftmaster - СШАUSA - 1946

When it was first introduced in 1933, the revolutionary Boeing 247, seen here, came without variable-pitch propellers. Shortly afterwards, as the single Douglas DC-1 was taking shape, it became clear that it would be substantially heavier than originally estimated. It would thus not be able to meet single-engine take-off requirements unless variable-pitch propellers were installed.

Самолёты на фотографии: Aircrafts on the photo: Boeing Model 247 - СШАUSA - 1933

Douglas chose the Wright F3 model of the R-1820 Cyclone for use in its new airliner, the DC-2. The Cyclone was Wright's first really successful air-cooled high power engine and its reliability gave passengers confidence in the twin-engine (rather than tri-motor) configuration.

Самолёты на фотографии: Aircrafts on the photo: Douglas DC-1 / DC-2 / C-32 / C-39 - СШАUSA - 1933

No less than three General Electric turbochargers were used to boost the power of the Wright TurboCompound to 3,700hp; thus making possible the Lockheed Super Constellation.

Самолёты на фотографии: Aircrafts on the photo: Lockheed Super Constellation L-1049 / C-121C - СШАUSA - 1951

No successful radial ever had more than nine cylinders in a single row, and no successful one ever had cylinders of greater individual displacement than the Pratt & Whitney Hornet - seen here powering a Boeing Model 40B-4.

Самолёты на фотографии: Aircrafts on the photo: Boeing Model 40 / Model 95 - СШАUSA - 1925

Replacing the earlier Jupiters’ cast aluminium crankcase with a forged one reduced the weight of the Jupiter VI by 7%. It was used on the DH.66 Hercules, with which Imperial Airways started its UK-India service, later extended to Australia.

Самолёты на фотографии: Aircrafts on the photo: De Havilland Hercules / D.H.66 - ВеликобританияUnited Kingdom - 1926