X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 13 Jul 2012 18:29:12 -0400 Message-ID: X-Original-Return-Path: Received: from mail-pb0-f52.google.com ([209.85.160.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.6) with ESMTPS id 5650965 for lml@lancaironline.net; Fri, 13 Jul 2012 16:20:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.160.52; envelope-from=pjdmiller@gmail.com Received: by pbbro8 with SMTP id ro8so6204895pbb.25 for ; Fri, 13 Jul 2012 13:19:44 -0700 (PDT) Received: by 10.68.192.39 with SMTP id hd7mr6374987pbc.97.1342210784377; Fri, 13 Jul 2012 13:19:44 -0700 (PDT) X-Original-Return-Path: Received: from [192.168.15.7] (S01060017ee00b6c0.cg.shawcable.net. [174.0.115.173]) by mx.google.com with ESMTPS id sy3sm6616469pbc.18.2012.07.13.13.19.41 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 13 Jul 2012 13:19:43 -0700 (PDT) From: Paul Miller Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-13-978841041 Subject: Re: [LML] Re: TAS for Red Line X-Original-Date: Fri, 13 Jul 2012 14:19:37 -0600 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <2FC4C821-4EFC-4D7F-8A35-7D9BE53CF204@gmail.com> X-Mailer: Apple Mail (2.1084) --Apple-Mail-13-978841041 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Turbines typically get Vno and not a Vne. That has Mach implications = for the high flyers and Mmo takes over depending on which is reached = first. For the TBM 700 I fly Vno is 266 and we get there only on full = power descents, not in cruise. Because of max altitude restrictions, = the max Mmo is not an issue for us and not listed in the POH. I'm = *guessing* the same issue goes for the IV-P? If you were able to go = higher then Mmo might become an issue and be listed if you had = sufficient power and it differed from the Vmo limits. It sounds like = the 276 KIAS limit probably takes all those factors into account with a = single safe number albeit close to what you cruise at and possibly = always under the Mmo figure. Paul Legacy, Calgary On 2012-07-13, at 1:58 PM, Bob Rickard wrote: > My IV-P shows a red line on the Chelton system at 276 KIAS. The POH = says the same. I have been close to there more than a few times, which = means if it is meant to be TAS I have been WAY over that. I highly = doubt Jeff Edwards messed that up when getting the flight certificate on = my airplane. Can't be right, I can almost cruise at 270 KTAS at FL250. = Definitely not a universal rule. >=20 > Bob R >=20 >=20 >=20 > On Jul 13, 2012, at 9:41 AM, Charles Brown = wrote: >=20 >> 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. >>=20 >> 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. >>=20 >> How many folks spend any time at redline? I've never gotten anywhere = near it in my Legacy. >>=20 >> Charley Brown >> Legacy #299 130 hr >>=20 >>=20 >> On Jul 12, 2012, at 9:26 PM, Steve Colwell wrote: >>=20 >> 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 >>=20 --Apple-Mail-13-978841041 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252
My IV-P shows a red line on = the Chelton system at 276 KIAS.  The POH says the same.  I = have been close to there more than a few times, which means if it is = meant to be TAS I have been WAY over that.  I highly doubt Jeff = Edwards messed that up when getting the flight certificate on my = airplane.  Can't be right, I can almost cruise at 270 KTAS at = FL250.  Definitely not a universal = rule.

Bob R



On Jul = 13, 2012, at 9:41 AM, Charles Brown <browncc1@verizon.net> = wrote:

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?? 
 


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