THE subject of aircraft engine installation has not received as much attention during the past as it should have done, particularly from an engineering and service standpoint. Many of the failures of power plants in the air have not been caused by engine failure, but by engine installation. It is believed that the major reason for this unfortunate condition is the lack of engineering when combining the aeroplane and engine. At the present time, engine installations are being made by aircraft designers and, while the engine designer is often consulted regarding the installation, he is not responsible for it.