GulfstreamGuy
Topic Author
Posts: 625
Joined: Sat Jul 03, 1999 6:30 am

737 A.p.u. Exhaust Holes

Thu Oct 14, 1999 1:34 pm

I noticed when 737s (mainly just Southwest here in LIT) come in, on all the -200s, -300s, and -500s, the auxillary power unit in the tail cone section have only one exhaust "hole". However, on the -700s they have TWO openings. Anybody know the reason for this?
"If we couldn't laugh, we would all go insane. " -Jimmy Buffett
 
jim
Posts: 448
Joined: Thu Jul 29, 1999 8:12 am

RE: 737 A.p.u. Exhaust Holes

Thu Oct 14, 1999 11:01 pm

It was explained to me that the second hole is used to ventilate and cool the APU compartment. Basically, the aft end of the tube is close enough to the exhaust to cause a venturi-effect, drawing air into the compartment. The forward end of the tube is next to the APU oil cooler, so air from the compartment is drawn across the oil cooler and exits overboard at the exhaust. I was told that the -700s & -800s have this.
-jim
 
GulfstreamGuy
Topic Author
Posts: 625
Joined: Sat Jul 03, 1999 6:30 am

RE: 737 A.p.u. Exhaust Holes

Fri Oct 15, 1999 5:35 am

Thanks Jim!
"If we couldn't laugh, we would all go insane. " -Jimmy Buffett

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