Return-Path: Sender: (Marvin Kaye) To: lml Date: Thu, 27 Jun 2002 19:27:43 -0400 Message-ID: X-Original-Return-Path: Received: from jsc-ems-vws04.jsc.nasa.gov ([139.169.39.51] verified) by logan.com (CommuniGate Pro SMTP 4.0b4) with SMTP id 1515384 for lml@lancaironline.net; Thu, 27 Jun 2002 17:10:17 -0400 Received: from 139.169.16.60 by jsc-ems-vws04.jsc.nasa.gov (InterScan E-Mail VirusWall NT); Thu, 27 Jun 2002 14:13:22 -0500 (Central Daylight Time) Received: by jsc-smtp02.jsc.nasa.gov with Internet Mail Service (5.5.2653.19) id ; Thu, 27 Jun 2002 14:13:22 -0500 X-Original-Message-ID: <1848CABD3587A84DAC6B3F82FE01D9FC01F1FA15@jsc-mail08.jsc.nasa.gov> From: "THORN, VALIN B. (JSC-OM) (NASA)" X-Original-To: "'lml@lancaironline.net'" Subject: Legacy Spin Testing? X-Original-Date: Thu, 27 Jun 2002 14:13:19 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" Okay, I'll take a turn at batting the hornets nest around a little... :) Many of the Lancair airplane accidents appear to be the result of stalling the airplane at low altitude. I think one of the root causes is that many Lancair pilots do not perform aggresive stall recognition/recovery practice because of the uncertain spin characteristics of the planes. I think aggressive stall practice results in more instinctive, faster, more appropriate pilot response when/if faced with a stall situation. Without known spin characteristics, most pilots appropriately assume an inadvertant spin would be unrecoverable/fatal and aggressive stall practice too risky, at any altitude. So, I'm somewhat surprised that most kit airplane companies do not spin test their designs, even though it's not legally required. It seems wise to characterize an airplane's spin behaviors, and improve them if necessary (make more spin resistant and recoverable), through a carefully conducted effort rather than leave it an unknown for customers to discover. If an airplane can easily go from basic, benign stall conditions to spinning, and/or not want to recover with corrective action, that should be known before some pilots/customers die discovering it. If poor spin characteristics are known, and not corrected, then at least everyone knows it is truely a "fatal keep out zone" and an appropriate margin of safety can be applied to flight procedures and stall recognition/recovery practice. If they are predictable and easily recoverable then the low speed, high angle of attack, edge of the envelope can be somewhat expanded and more aggressive stall recognition/recovery practice can be more safely conducted. After the first-flight test pilot, no one else will fly in our Legacy until I have carefully characterized its stall behaviors. I just think it's too important a risk area to leave unexplored before exposing anyone else in our plane to the risk -- even flying under experimental registration. We will employ stall strips and/or vortex generators, etc., if needed, at least until with power off, and no side-slip, both wings stall symetrically (little to no roll off). Is "one ball" of side-slip during a stall enough to start a spin in a Legacy? Are take-off/departure stalls guaranteed to spin? Characterizing and improving our Legacy's stall characteristics will require flirting with an inadvertant spin which could be unrecoverable. I think most Legacy builder's with similar opinions would prefer to conduct stall testing/tweeking with a clearer idea of the probability and consequences of a Legacy's spin entry and recovery -- so why don't we spin test one? I believe we Legacy builders could have the Legacy spin tested for less cost than one might think. We need a flying Legacy outfitted with a spin parachute, an experience light aircraft test pilot, an aeronautical engineer with appropriate experience, insurance, and money to compensate the participants and cover other expenses. I can only contribute to the money part since I'm not a test pilot, nor appropriately experienced engineer (space systems engineering), and our Legacy is a few years from flying. Any thoughts on this proposal? I know from reading the list that there are several people who've been involved in this kind of work. What would it take to pull off? Anyone interested in organizing this effort? I'm willing to contribute to a fund for Legacy spin testing. I think there are already over 100 Legacy builders -- if everyone pitched in $500 that's over $50K... Anyone know enough about the details to better estimate the costs? Would you, as a Legacy builder, pay $500 to provide Legacy spin testing and eliminate this vital unknown? I'll pay more than that if needed... Valin Thorn Legacy Kit 173 P.S. By the way, our Legacy absolutely will have an AOA indicator (e.g. Jim Frantz's system) and I'm astonished that they are not already legally required equipment in all airplanes.