Return-Path: Received: from smtp01.mrf.mail.rcn.net ([207.172.4.60]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Mon, 9 Oct 2000 06:53:45 -0400 Received: from 207-172-110-221.s221.tnt1.frd.va.dialup.rcn.com ([207.172.110.221] helo=oemcomputer) by smtp01.mrf.mail.rcn.net with smtp (Exim 3.15 #2) id 13iaft-0002KR-00 for lancair.list@olsusa.com; Mon, 09 Oct 2000 07:00:54 -0400 Message-ID: <002c01c031e0$6e59fb40$dd6eaccf@oemcomputer> From: "Bill & Sue" To: References: <20001009044649.AAA22016@ns1.olsusa.com> Subject: Hard Landing Date: Mon, 9 Oct 2000 07:02:34 -0400 X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> > In the subsequent discussions I didn't see any mention of the fact that > stall speed increases with altitude. Brent, Your analysis of stall speed vs density altitude is valid but it relates to TRUE airspeed. The decrease in air density that causes the stall speed increase causes a lower INDICATED airspeed at a given TRUE airspeed. Until you get up to speeds where compressibility becomes a factor, an airplane in a given configuration and at a given weight should stall at the same INDICATED airspeed regardless of density altitude. Adding extra INDICATED airspeed for a high density altitude take-of or landing is not necessary. Having said that I know that during the landing flare or during take-off rotation we're looking outside and the intuitive tendancy is to relate airplane performance to GROUNDSPEED. Even in calm conditions the ground is going to be passing by much faster at the hight density airport than we're used to down low. Under high density conditions it would be good to remember your stall speed analysis and be mentally ready to see a higher ground speed out the windshield, but to try to approach or rotate at the same indicated speeds. Better still, fly a constant ANGLE OF ATTACK on your AOA gauge. Bill Harrelson harrelson@erols.com >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>