sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (04/10/90)
From: sysmgr@KING.ENG.UMD.EDU (Doug Mohney) In article <15311@cbnews.ATT.COM>, uwm!carroll1.cc.edu!tkopp@uunet.UU.NET (Tom Kopp) writes: > >........................... A Fulcrum (MiG-29) crashed, apparently from >a piece of airframe or other FOD that went through an engine. That nobody >was hurt is a testimonial to the pilot's training. He was VERY low when >the trouble occurred, yet he managed to point the crippled aircraft away >from the crowd. When he punched out, his parachute was ~ 50% deployed when he >hit the ground. Also was a testimonial to the ejection seat in the plane, which wasn't tested for such extreme conditions. >As to your Flanker / Eagle comparison, your smiley indicated that you think >the F-15's got it beat............................................ >Supposedly, this aircraft was designed with the intention of besting >Tomcats and Eagles, and the estimates made here for maneuverability indicate >"Good" for the Eagle and "Very Good to Excellent" for the Flanker. > >Anyone who has information on which plane *REALLY* has an upper hand, please >comment. The Sovs wanted to have an exchange program where U.S. pilots could fly the latest and greatest of Mother Russia and vice versa. The designer of the Su-27 wants to have an international aerobatics competition between his plane and all comes in the West. HE thinks his baby will best 'em...
willner%cfa183@harvard.harvard.edu (Steve Willner) (04/11/90)
From: willner%cfa183@harvard.harvard.edu (Steve Willner) > The Su-27 is the plane that did the 'Cobra'. This is what is truly amazing. > The plane went through not "nearly 90 vertical" as you said, but *BEYOND* > vertical. 110 degree angle-of-attack! The pilot chopped something like > 200 kts. off his airspeed in about 3 seconds, if I remember right. An impressive maneuver, as reported in several postings. But does the 110 or 120 degrees refer to _angle of attack_ or to _pitch angle_? The two are not synonymous; I can easily believe the latter, but the former seems almost impossible. (And makes the feat all the more spectacular if correct!) ------------------------------------------------------------------------- Steve Willner Phone 617-495-7123 Bitnet: willner@cfa Cambridge, MA 02138 USA Internet: willner@cfa.harvard.edu
willner%cfa183@harvard.harvard.edu (Steve Willner) (04/14/90)
From: willner%cfa183@harvard.harvard.edu (Steve Willner) In article <15435@cbnews.ATT.COM>, referring to the "Cobra maneuver" performed by the Su-27, I asked: > Does 110 or 120 degrees refer to _angle of attack_ or to _pitch angle_? > The two are not synonymous; I can easily believe the latter, but the > former seems almost impossible. Here's what Aviation Week had to say in their March 5 issue: "[Two Soviet pilots] flew several "Cobra" profiles, a rapid deceleration maneuver during which the throttles are cut on the Su-27's two 30,000-lb. thrust Lyulka AL31F engines and the aircraft is pitched rapidly up past the vertical position, sometimes as far as 110-120 deg. As the aircraft decelerates, the nose is pitched down and the aircraft is recovered with power and accelerated in horizontal flight." The article also states that the speed goes from 200 to 65 knots and the altitude loss is only 100 feet. The AWST information refers to pitch angle, but what about angle of attack? Mary Shafer has kindly explained to me that the whole pitch-up maneuver takes place so rapidly that the airplane flight path continues forward. This means that the angle of attack is essentially equal to the pitch angle and really does exceed 90 degrees. This means that the Su-27 was (briefly) flying (slightly) backwards! I'm impressed! [Mary also makes the point that aeronautical types use many different coordinate systems. Here I'm using "pitch angle" to mean the instantaneous angle between horizontal and the aircraft fuselage reference and "angle of attack" to mean the angle between fuselage reference (or airfoil reference) and the relative wind. I think these are the usual definitions in semi-technical discussions. In a steady vertical climb, for example, the pitch angle would be 90 degrees and the angle of attack would be 0 degrees by these definitions.] Mary also points out that the Cobra maneuver actually takes very little time, though some slow-motion videos don't make that obvious. ~