X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 13 Jul 2012 11:41:47 -0400 Message-ID: X-Original-Return-Path: Received: from nm19-vm0.bullet.mail.ac4.yahoo.com ([98.139.53.212] verified) by logan.com (CommuniGate Pro SMTP 5.4.6) with SMTP id 5649719 for lml@lancaironline.net; Thu, 12 Jul 2012 23:03:57 -0400 Received-SPF: neutral receiver=logan.com; client-ip=98.139.53.212; envelope-from=browncc1@verizon.net Received: from [98.139.52.190] by nm19.bullet.mail.ac4.yahoo.com with NNFMP; 13 Jul 2012 03:03:22 -0000 Received: from [209.191.108.96] by tm3.bullet.mail.ac4.yahoo.com with NNFMP; 13 Jul 2012 03:03:22 -0000 Received: from [66.94.237.97] by t3.bullet.mud.yahoo.com with NNFMP; 13 Jul 2012 03:03:22 -0000 Received: from [127.0.0.1] by omp1002.access.mail.mud.yahoo.com with NNFMP; 13 Jul 2012 03:03:22 -0000 X-Yahoo-Newman-Id: 498536.43610.bm@omp1002.access.mail.mud.yahoo.com Received: (qmail 71426 invoked from network); 13 Jul 2012 03:03:22 -0000 X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: fA_c2B4VM1kFkYZzCGoF5mRQKb2WWcTreYfEfZRiUWKY6MT CvmmuRxCFxuhlcRX6mL6huxoWsc1ImmiKN3UfXUwaI6osMT2jW8aiAQxHaau e9CF8ZlKL.gy6yda_EPXjXMCk2kCMo6jc4s3JRx5B0CMDrKEz3u8b6Szu2BC G6LNzQ0whynodjamWGV_i23NUHAqVkiyK1U_Tu9xepRVKRLrUskWhA_HMkL. ZPs24KtRYrBcls4dD0v39PcUNKyPvOrsIiXmD9rpbiKJmpYsXxODZowOfkDF WZvLajh6v3MWroMieRt2myyuYo_.ciW2prOomuQI7oFuBA2DbyIGK3UsuyIA wSxnQQCXeSMIoG1JWSZPVs8HlJd3O10.2XROcSrJM_4ChF1MYFQJJ3I1dpPE cAmf2R85Zia6iXnTDkKblTcYOy4VbIUX7gJ1eZOisuIUsvl6MtRksfoTyaCX Syw2EPFxZpURm_B4GRDQIqDHwTO.8sJZGe1Tmni.Wx49qaaisxOn2ZmjPbww ADiEXJznF9zDnHu8xq9zDy0YyAQ-- X-Yahoo-SMTP: F49l9g6swBC0R9n8vJIbm7Tf3P8Xlmia8rHIwTlO__Ml Received: from chass-imac-2.home (browncc1@72.64.105.53 with plain) by smtp104.vzn.mail.ne1.yahoo.com with SMTP; 12 Jul 2012 20:03:21 -0700 PDT From: Charles Brown Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-3-916664707 Subject: Re: [LML] TAS for Red Line X-Original-Date: Thu, 12 Jul 2012 22:03:21 -0500 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <03A9981B-91BD-4267-AFD5-8F67F1B8BFF2@verizon.net> X-Mailer: Apple Mail (2.1084) --Apple-Mail-3-916664707 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Well that's interesting. FAR Part 23 (airworthiness standards for = normal, utility, acrobatic and commuter airplanes) Section 1545 = (airspeed indicator) says that the airspeed indicator must be marked = with a red line at Vne (that would be an indicated airspeed) and that if = Vne varies with altitude, there must be a way of indicating Vne to the = pilot throughout the envelope. For airplanes operating at Mach numbers = where compressibility matters (not Lancairs), Vmo is defined in = Equivalent airspeed, which is still very close to IAS, and there has to = be a way of showing the variation of Vmo/Mmo with altitude and Mach = number. I've never met a light aircraft instrument system that had a primary = airspeed indicator with anything *other* than IAS, and just one redline = value. The Garmin 900, and I guess other EFISs, also read TAS but not = on a big pretty scale with a redline. You can set the redline on the = airspeed tape conservatively so that it's below the lowest TAS for = flutter at any altitude; then you give away a few knots at lower = altitudes. How many folks spend any time at redline? I've never gotten anywhere = near it in my Legacy. Charley Brown Legacy #299 130 hr On Jul 12, 2012, at 9:26 PM, Steve Colwell wrote: Having coffee with some high time pilots this morning, the subject of = Never Exceed Speed came up. Before I read the original Van=92s article = years ago, I thought Indicated Airspeed was the indicator=85 WRONG, it = is True Airspeed. Does your EFIS display TAS or do you have a table for = reference??=20 =20 http://www.vansaircraft.com/pdf/hp_limts.pdf=20 =20 Steve Colwell Legacy --Apple-Mail-3-916664707 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252
Well that's interesting.  FAR Part 23 = (airworthiness standards for normal, utility, acrobatic and commuter = airplanes) Section 1545 (airspeed indicator) says that the airspeed = indicator must be marked with a red line at Vne (that would be an = indicated airspeed) and that if Vne varies with altitude, there must be = a way of indicating Vne to the pilot throughout the envelope.  For = airplanes operating at Mach numbers where compressibility matters (not = Lancairs), Vmo is defined in Equivalent airspeed, which is still very = close to IAS, and there has to be a way of showing the variation of = Vmo/Mmo with altitude and Mach number.

I've = never met a light aircraft instrument system that had a primary airspeed = indicator with anything *other* than IAS, and just one redline value. =  The Garmin 900, and I guess other EFISs, also read TAS but not on = a big pretty scale with a redline.  You can set the redline on the = airspeed tape conservatively so that it's below the lowest TAS for = flutter at any altitude; then you give away a few knots at lower = altitudes.

How many folks spend any time at = redline?  I've never gotten anywhere near it in my = Legacy.

Charley Brown
Legacy #299 =  130 hr


On Jul 12, 2012, at 9:26 = PM, Steve Colwell wrote:

Having coffee with some high time pilots this morning, the = subject of Never Exceed Speed came up.  Before I read the original = Van=92s article years ago, I thought Indicated Airspeed was the = indicator=85  WRONG, it is True Airspeed.  Does your EFIS = display TAS or do you have a table for = reference?? 
 

= --Apple-Mail-3-916664707--