Apparently HiTech needs to visit this thread. New patch says that the new rules for engine sounds only applies to GVs apparently.
Fixed a bug with the change to external engine sounds that kept it from working correctly. The change with external engine sounds only playing when your own engine is off only applies to vehicles.
No need, it's in the patch notes
Apparently you misunderstood me. I think that the engine sound change should apply to aircraft also.