Starlionblue From Greenland, joined Feb 2004, 17297 posts, RR: 67
Reply 4, posted (3 years 10 months 1 week 5 days 3 hours ago) and read 3370 times:
Just to expand, the fairing is a cover that makes an aerodynamic shape, lowering drag. Most aircraft can despatch with one or more missing but there is a drag penalty since the "naked" mechanism is not very aerodynamic.
The fairings have two other functions:
- They protect the flap mechanism from damage.
- They make the aircraft conform more closely to the area rule, and thus lower drag further.
"There are no stupid questions, but there are a lot of inquisitive idiots."
HAWK21M From India, joined Jan 2001, 31754 posts, RR: 55
Reply 6, posted (3 years 9 months 3 weeks 4 days 18 hours ago) and read 2688 times:
Flap track fairng/canoe is normally the aft portion covering the TE Flap track mechanism.
Provides Aerodynamic covering to the mechanism it houses,reduces drag.
Normally has a drain hole at the tip to permit moisture drainage.Tapers down with increased Flap deployment.
The Classic B737s had the outboard fairings with a retractable Landing light that did have some snags to the mechanism.
yeelep From United States of America, joined Apr 2011, 696 posts, RR: 0
Reply 7, posted (3 years 9 months 3 weeks 4 days 15 hours ago) and read 2607 times:
Just to add to the above. On the NG, Boeing likes to call them flap support fairings, though everybody calls them flap fairings, canoes or flap track fairings. They are made up of three parts, the fwd, aft and tailcone fairing. In the above picture you see all of the tailcone and about a foot of the aft fairing.
Quoting Starlionblue (Reply 4): Most aircraft can despatch with one or more missing but there is a drag penalty since the "naked" mechanism is not very aerodynamic.
The NG's have eight flap tracks numbered 1 through 8 aircraft left to right. 1 and 8 can dispatch with all three fairing sections or just the tailcone missing. 2,3,6 and 7 can dispatch with only the tailcone missing. 4 and 5 are in the wheel well/body fairing area and don't have fairings.
Quoting HAWK21M (Reply 6): The Classic B737s had the outboard fairings with a retractable Landing light that did have some snags to the mechanism.
The Classics outboard flap fairings are also an integral part of the aft flap drive system, which may have looked good when it was designed, but in practice, not so much. IMO from a mechanics perspective, the flap design of the NG was the single greatest improvement made over the classic.