Tripl7 From , joined Dec 1969, posts, RR: Posted (13 years 2 weeks 6 hours ago) and read 1083 times:
Anyone ever noticed that the 737NG have two exhaust holes on top of each other instead of just one?
Can anyone explain why please?
It certainly sounds a lot quiter at close range. Could this be the reason?
Thanks guys !
Yaki1 From , joined Dec 1969, posts, RR: Reply 1, posted (13 years 2 weeks 4 hours ago) and read 883 times:
The upper hole is for the eductor cooling system, it cools the APU compartment and the APU oil. It eliminates the oil cooler fan, operating on APU exhaust it has no moving parts.