flap (redirected from envelope flap)

FLAP

The communications protocol used by AOL Instant Messenger (AIM). FLAP runs over TCP/IP and provides the header format for transmitting IM commands and data. It includes the SNAC data type, which is the primary data structure transmitted between clients and servers. See OSCAR.

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flap

1. Aviation a movable surface fixed to the trailing edge of an aircraft wing that increases lift during takeoff and drag during landing

2. Surgery a piece of tissue partially connected to the body, either following an amputation or to be used as a graft

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flap [flap]

(aerospace engineering)

Any control surface, such as a speed brake, dive brake, or dive-recovery brake, used primarily to increase the lift or drag on an airplane, or to aid in recovery from a dive.

Any rudder attached to a rocket and acting either in the air or within the jet stream.

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1.		FLAP - A symbolic mathematics package for IBM 360. ["FLAP Programmer's Manual", A.H. Morris Jr., TR-2558 (1971) US Naval Weapons Lab]. [Sammet 1969, p. 506].
2.	(storage, jargon)	flap - To unload a DECtape (so it goes flap, flap, flap). Old-time hackers at MIT tell of the days when the disk was device 0 and microtapes were 1, 2, etc. and attempting to flap device 0 would instead start a motor banging inside a cabinet near the disk. The term is used, by extension, for unloading any magnetic tape. See also macrotape. Modern cartridge tapes no longer actually flap, but the usage has remained. The term could well be re-applied to DEC's TK50 cartridge tape drive, a spectacularly misengineered contraption which makes a loud flapping sound, almost like an old reel-type lawnmower, in one of its many tape-eating failure modes.
3.	(networking)	flap - See flapping router.