Zionstrat From United States of America, joined Apr 2001, 226 posts, RR: 0 Posted (12 years 9 months 2 weeks 6 days 4 hours ago) and read 2643 times:
My question is easier to show than to describe- If you look at the rear right fuselage of the first and 3rd 737s, you will notice what appears to be a 'handle' on the right rear fuselage (just aft of the door) and I'd love to know what it is-
Broke From United States of America, joined Apr 2002, 1322 posts, RR: 3
Reply 2, posted (12 years 9 months 2 weeks 6 days 4 hours ago) and read 2606 times:
What you call the "handle" is a aerodynamic deflector designed to increase the airflow into the flush inlet mounted on the fuselage. The inlet, itself, was developed by the National Advisory Committee for Aeronautic (NACA and the predecessor of NASA) in the US and the inlet is called a "NACA Inlet". I believe that this inlet is the air intake for the Auxiliary Power Unit (APU) that is mounted in the rear fuselage of the 737. You can see the exhaust of the APU at the extreme rear of the fuselage. The deflector (I'm not sure what Boeing calls it) is needed when operating the APU in flight, but not on the ground. The APU provides air for engine starts and air conditioning and electrical power on the ground. In flight, it provides electrical power when one of the engine driven generators is inoperative or is a back-up to the engine driven generators when making precision approaches in bad weather. The later use is required for what are known as CAT 3 approaches.
Zionstrat From United States of America, joined Apr 2001, 226 posts, RR: 0
Reply 4, posted (12 years 9 months 2 weeks 6 days 3 hours ago) and read 2584 times:
That's ironic- Apu intake was my first guess until I got a close look at one this weekend and decided it would generate too much drag for an intake- Shows that I can't visualize NACA inlets very well.
Not the first time I've been fooled- I always thought that the P51 belly airscoop looked like a ridiculous source of drag until I learned that it was actually quite clean apparently due to the NACA spec-
Kcle From United States of America, joined Feb 2001, 686 posts, RR: 0
Reply 9, posted (12 years 9 months 2 weeks 5 days 16 hours ago) and read 2454 times:
Since we are talking about the rears of 737's, what are those series of pipes on the top of the fuselage right next to the rudder? There are four pipes on each side of the rudder, protruding from the fuselage about 6 inches. They are all in a column. I haven't seen any good pics of these things, but I myself have an excellent pic of them, but I'm too lazy to scan it and try to find a web site to load them to.