jetliner145
Posts: 77
Joined: Mon Jul 19, 2004 11:42 am

DC-9/MD-80/B717

Sat Jul 24, 2004 4:38 am

Hello all,
This is something that has been puzzling me. I know that the DC-9, MD-80, & the B717 all have APUs, but what puzzeled me was where is the air intake? Where does it come out? I've looked at many pictures of all those types of aircraft, and I just can figure out where they {APUs} are. If anyone can help please do. Thanks

jetliner Smile/happy/getting dizzy
Continental, Work Hard, Fly Right
 
NKP S2
Posts: 1665
Joined: Mon Dec 20, 1999 3:16 am

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 4:58 am

On the underside of the aft fuselage, immediately fwd of the aft airstairs. It's not very visible since the ram air scoop is seldom deployed except during starting cycle or commanded open.

Can't speak for the 717.
 
FBU 4EVER!
Posts: 980
Joined: Sat Jan 27, 2001 6:53 am

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 5:00 am

The APU is located in the aft fuselage,aft of the rear pressure bulkhead,just forward of the ventral airstairs.
The air intake is on the underside of the fuselage,not the air intake at the bottom of the vertical fin as many believe. It is a "scoop" like affair extending during APU start. It retracts after starting and two "flap" doors open and supply air to the running APU. The exhaust is on the right hand side of the fuselage,just above the rear half of the engine pylon.
"Luck and superstition wins all the time"!
 
LMP737
Posts: 4810
Joined: Wed May 08, 2002 4:06 pm

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 5:05 am

Unlike the MD-80 the APU intake on the 717 is located on top of the fuselage. There's a noticeable noise reduction also.
Never take financial advice from co-workers.
 
atlamt
Posts: 244
Joined: Thu Sep 13, 2001 12:15 am

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 6:51 am

The MD-80's were plagued with air turnbacks due to smoke in the cabin/ burning smell caused by the apu ingesting hydraulic fluid. The drains for the tail compartment are just forward of the apu intake. The 717's apu intake was moved for this reason.
Fwd to MCO and Placard
 
User avatar
Starlionblue
Posts: 17087
Joined: Fri Feb 27, 2004 9:54 pm

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 8:24 am

This should clarify where the exhaust is located


View Large View Medium
Click here for bigger photo!

Photo © Philippe Bleus

"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
jetliner145
Posts: 77
Joined: Mon Jul 19, 2004 11:42 am

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 10:30 am

Thanks everyone for explaning.

jetliner Smile/happy/getting dizzy
Continental, Work Hard, Fly Right
 
SlamClick
Posts: 9576
Joined: Sun Nov 23, 2003 7:09 am

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 10:35 am

Just barely visible here.

View Large View Medium
Click here for bigger photo!

Photo © Peter Fagerström


Look just above the silver part of the engine on the far side, and just forward of what appears to be a drain mast. You will see a small square area that is the APU inlet door in the closed position. In the non-ram position you would see a rectangular opening, transverse, and in the ram, there would be a slight extension of the aft part of the door into the slipstream.
Happiness is not seeing another trite Ste. Maarten photo all week long.
 
Dalmd88
Posts: 2399
Joined: Fri Jul 28, 2000 3:19 am

RE: DC-9/MD-80/B717

Sat Jul 24, 2004 7:23 pm

Ok I've looked at a bunch of pictures of the 717. Where is the intake? All I can see is the Ram intake at the bottom of the vertical, the apu exhaust on the right side, and the aircycle machine exhaust on each side.
 
BR715-A1-30
Posts: 6525
Joined: Thu May 30, 2002 9:30 am

RE: DC-9/MD-80/B717

Sun Jul 25, 2004 1:10 am


View Large View Medium
Click here for bigger photo!

Photo © AirNikon

See the hole with the red rectangle around it? That is the APU intake for the 717. The exhaust is in the same position on the other side.
Puhdiddle

Who is online

Users browsing this forum: 9vswr, FBWFTW, zaphod42 and 12 guests