[rotorwrench]

Aviation is where the ester based synthetics started out for high temperature operations in turbine shaft and turbojet engines. Using mineral oil in them would be a disaster. In reciprocating aircraft engines, they tried straight synthetic oils but had problems so it was discontinued. Aircraft engines run hotter than the automotive engines due to them being air cooled.


Some of the misconceptions likely came from those problems but they have what are called semi-synthetics now. The engines would fail with those oils in the helicopters down here in Texas. They can only use straight grade 100 SAE 50 oils if they want them to last to TBO. Airplanes can and do get up to altitudes where the temperature is down right cold so it works OK for the most part. Helicopters general stay down low where there is better density for lift.