Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!att!cbnews!military From: shafer@drynix (Mary Shafer) Newsgroups: sci.military Subject: Re: Dogfighting Message-ID: <7471@cbnews.ATT.COM> Date: 15 Jun 89 03:53:12 GMT Sender: military@cbnews.ATT.COM Lines: 71 Approved: military@att.att.com From: Mary Shafer David Gardiner writes: > Aircraft maneuvering technology seems to be heading away from high G > turns to other forms of maneuverability, such as piroette turns (stand > the plane on it's tail and spin). At least one of the new X planes > is designed to research this (the X-31, I believe). The X-29 is testing > high angle of attack but I do not know the details. The X-29 isn't going to go to very high alpha, only about 25 or 30 deg. This sounds impressive compared to F-4s for example, but the F-18 can trim above 40 deg alpha and can go to 70 deg quite nicely. [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 ] Incidentally, the latest buzz word for all this is `agility', with the terms 'maneuverablity', `post-stall maneuverability', and `supermaneuverablity' also used. I'm the technical monitor on an SBIR to develop displays to make all this agility more useful to the pilot. This is the real challenge, since it does no good to have a capability if it's not used. A pilot will be reluctant to bleed off all his airspeed and energy at high alpha, unless he knows that he'll get a good shot at the opponent. Otherwise he has made himself very vulnerable, out of energy with no place to go. We're looking at ways of letting the pilot know whether he can get a weapons solution or not. Agility is a very hot topic right now. There are a lot of people working on this problem, including NASA Langley, USAF at Wright Research & Development Center, McDonnell Aircraft, etc. I think there's going to be at least one agility session at the AIAA Atmospheric Flight Mechanics Conference in Boston in August. (Advertisement--come see my paper there on Monday afternoon, August 14. It's about flying qualities, not agility, but it's good anyway :-) and I have a video with real aircraft on it.) Another important element is the weapon envelope. If you can't launch a missile at 70 deg, what good does it do to go to 70 deg? You're only there to kill the other aircraft. I attended an agility workshop at the AIAA conference in Reno this January. One exchange between a questioner and the NASA ADFRF pilot on the panel went approximately like this: Q: What do you do if you engage an aircraft as agile as yours? What if you can't beat him? A: I pop off a missile and bug out. Q: Why launch the missile? A: To give him something to really worry about! There are very few worries so imperative as where is the live missile. Here's a book recommendation: "Modern Combat Aircraft Design" by Klaus Huenecke, copyright 1984 and published in English in the US and Canada in 1987 by the Naval Institute. This is an extremely good book that goes into philosophy and history as well as the boring engineering stuff. It's well illustrated and is accessible (IMO) to people who aren't aero engineers. I recommend it strongly to group readers interested in fighters. M F Shafer |Ignore the reply-to address NASA Ames-Dryden Flight Research Facility |Use shafer@elxsi.dfrf.nasa.gov NASA management doesn't know what I'm doing and I don't know what they're doing, and everybody's happy this way.