Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!cs.utexas.edu!rutgers!tut.cis.ohio-state.edu!att!cbnews!military From: caeco!iconsys!tom@uunet.UU.NET (Tom Kimpton) Newsgroups: sci.military Subject: Angle of Attack (was Re: Dogfighting) Message-ID: <7903@cbnews.ATT.COM> Date: 30 Jun 89 20:10:29 GMT References: <7471@cbnews.ATT.COM> <7575@cbnews.ATT.COM> Sender: military@cbnews.ATT.COM Organization: ICON International, Inc., Orem, UT Lines: 48 Approved: military@att.att.com From: caeco!iconsys!tom@uunet.UU.NET (Tom Kimpton) In article <7575@cbnews.ATT.COM> fiddler@Sun.COM (Steve Hix) writes: : : :From: fiddler@Sun.COM (Steve Hix) : :> [mod.note: For those of us unfamiliar (me included)... I take it :> alpha == angle of attack. Now, what's angle of attack ? Does (I'm :> guessing from context) an alpha of 30 degrees mean the plane can :> fly level with its nose 30 degrees above level ? - Bill ] : :No. Not quite. : :Take a line between the leading and trailing edges of the wing. :That's a chord. Measure the angle between the chord line and :the direction the air going due to the aircraft's motion. : :The angle is what you're looking for. : :(Roughly, a wing's lift [and drag] increase with increasing angle of attack. :Up to a point...past that point, lift falls off, usually with a related :separation of airflow from the wing. At that point the wing stalls. : There was an article in the 22 May 89 issue of Aviation Week & Space Technology, "NASA Adds to Understanding of High Angle of Attack Regime", that talks about high angle of attack research using an F/A-18. Good article: "The former Navy F/A-18 has completed 83 flights and reached stabilized angle of attack up to 55 deg." "At 34 dg. AOA, in stablilized flight, most of the lift appears to come from the aircraft fuselage and LEX (leading edge extension). Most of the wing is stalled and the vertical tails appear to be largely blanked out, wich minimizes lateral and directional control at these flight conditions." Also a related article in 29 May 89: "Modified F-15B to Demonstrate STOL, Maneuver Capability". -- Tom Kimpton UUCP: {uunet,caeco,nrc-ut}!iconsys!tom Software Development Engineer ARPANET: icon%byuadam.bitnet@cunyvm.cuny.edu Icon International, Inc. BITNET: icon%byuadam.bitnet (multi-user acct) Orem, Utah 84058 PHONE: (801) 225-6888