Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.4.5) with ESMTP id 777069 for rob@logan.com; Fri, 11 May 2001 07:37:08 -0400 Received: from imo-r19.mx.aol.com ([152.163.225.73]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71175U5500L550S0V35) with ESMTP id com for ; Fri, 11 May 2001 06:33:56 -0400 Received: from BOBPAS26@aol.com by imo-r19.mx.aol.com (mail_out_v30.10.) id k.ac.14d710fa (4458) for ; Fri, 11 May 2001 06:40:43 -0400 (EDT) From: BOBPAS26@aol.com Message-ID: Date: Fri, 11 May 2001 06:40:43 EDT Subject: Groundspeed as a Flight Reference To: lancair.list@olsusa.com MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> << Greg Nelson wrote: Am I Wrong? Unless I am landing or taking off under extreme conditions (such as hot, humid, heavy, SNIP ............................................................ Greg, you did put most of the right caveats on your use of groundspeed as a flight/performance reference. Groundspeed is needed to compute how long it will take you from A to B, and indirectly how much fuel you will consume in the process, but is not a valid measurement for any flight performance characteristics about your airplane. Further, GPS groundspeed typically lags the actual groundspeed when changing flight conditions due to the lag/buffers intentionally built in the GPS computer. Admittedly, groundspeed approximates the performance-driving airspeed values closely enough in most cases to be used, but as I have personally observed, the "other 2% can kill you." and more often than that mess up a perfectly good Lancair. I presume your comments about these old terms were made at least partly in jest, but their basis is valid and grounded (pun intended) in hard-learned lessons. While groundspeed is probably the best in-flight/cruise reference for at least part of your planning/use, consider using an airspeed reference for all other flight operations. Bob Pastusek >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 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. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>