X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 10 Dec 2009 15:02:53 -0500 Message-ID: X-Original-Return-Path: Received: from mail2.gladtech.net ([76.77.134.182] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTPS id 4013842 for lml@lancaironline.net; Thu, 10 Dec 2009 09:35:35 -0500 Received-SPF: neutral receiver=logan.com; client-ip=76.77.134.182; envelope-from=chatdaniel@centurybankonline.com Received: from ([151.213.202.2]) by mail2.gladtech.net with ESMTP with TLS id 5503689.9906034; Thu, 10 Dec 2009 08:34:42 -0600 Received: from Exchange.Century.local ([::1]) by Exchange.Century.local ([::1]) with mapi; Thu, 10 Dec 2009 09:37:01 -0500 From: Chat Daniel X-Original-To: Lancair Mailing List X-Original-Date: Thu, 10 Dec 2009 09:36:59 -0500 Subject: RE: [LML] Re: Vne discussion Thread-Topic: [LML] Re: Vne discussion Thread-Index: Acp5DvcGbyTBCjCIR8Wzc5jeCi5nHwAllbHg X-Original-Message-ID: <224AEB147425D947B9FE2AE2B54E8B2C1DE1D6D1@Exchange.Century.local> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Flutter is a function of true air speed and structural failure is a functio= n of indicated air speed=2E Both should be considered in VNE=2E Read thes= e articles=2E http://www=2Evansairforce=2Ecom/community/showthread=2Ephp?t= =3D41255=0D=0AChat Daniel=0D=0A=0D=0A=0D=0A-----Original Message-----=0D=0A= From: Lancair Mailing List [mailto:lml@lancaironline=2Enet] On Behalf Of Ma= tt losangeles=0D=0ASent: Wednesday, December 09, 2009 3:31 PM=0D=0ATo: lml@= lancaironline=2Enet=0D=0ASubject: [LML] Re: Vne discussion=0D=0A=0D=0AA few= years ago I owned a Mooney with a Rayjay turbo that was installed via an S= TC=2E On the panel, there was a placard that was added saying "reduce VNE 5= knots for each 1000 feet over 23400 feet=2E" I think the Mooney was origi= nally certified to 18000 feet and this STC increased it to 24000 feet=2E Ba= sed on that I have always figured VNE was not based on TAS or IAS but some = kind of calculation of both and likely other factors=2E I am planning on ad= ding a Turbo normalizer to my Legacy so getting to the bottom of this is im= portant to me or I am going to have to slow down in decent from high altitu= te at all times=2E I sure would like to be able to keep the power in on dec= ent if possible=2E If I can't find any conclusive information I am going to= have to assume the worst of TAS not exceeding 274 knots=2E=0D=0A=0D=0AMatt= =0D=0A=0D=0A=0D=0A=0D=0A----- Original Message ----=0D=0AFrom: Dr=2E Weinsw= eig =0D=0ATo: lml@lancaironline=2Enet=0D=0ASent: We= d, December 9, 2009 9:04:43 AM=0D=0ASubject: [LML] Re: Vne discussion=0D=0A= =0D=0A=0D=0Ayes, this whole thing about mach limitting speed is rather new= to me also=2E i don't really remember being taught about it in initial or= recurrent training(though i do subscribe to grayhawk's theory of new info = requires old info to leave the brain-lol!)=2E what i am understanding from= this discussion is that vne for lancairs is indicated airspeed ie 274 kia= s for a iv=2E but the mach speed for a iv that should not be exceeded due= to flutter considerations is 0=2E57mach ie =2E57 x 761=3D433 mph Tas or 38= 2 kTas=2E is this correct? still not quite sure why this mach speed is in= tas and not ias=2E but if this is true it has definite ramifications for = a iv or propet particularly during descent=2E despite the few flames, this= has been an interesting and practical discussion=2E=0D=0A=0D=0Adavid weins= weig=0D=0An750dw propjet=0D=0A178 hours=0D=0A=0D=0A=0D=0A>>> bknotts@buckey= e-express=2Ecom 12/09/2009 8:12 AM >>>=0D=0AI haven't seen much on Mmo=2E = In fact, this is the first time I've heard=0D=0Aof a limiting mach number f= or the IV-P=2E My Chilton PFD shows any mach=0D=0Aabove =2E35 at the top o= f the airspeed tape=2E I've seen =2E44 in cruise at=0D=0Aaltitude=2E (I g= iggled like a little girl=2E) Now I'm a little concerned=0D=0Athat the "ha= rd" Mmo should be placarded so as not to exceed it in a=0D=0Acruise power (= usual) descent=2E=0D=0A=0D=0ABarry Knotts=0D=0AN4XE, LIV-P, Conti TSIO-550= =0D=0A=0D=0AFrederick Moreno wrote:=0D=0A>=0D=0A>=0D=0A> When Brent Regan a= nd I were racing his Lancair IV Denver to Oshkosh=0D=0A> (1996, 97 as I rec= all), the descent profile was Mach limited initially=0D=0A> starting at 27,= 000 feet using a hard limit of Mach 0=2E58=2E This was=0D=0A> chosen becau= se the factory aircraft was test flown to Mach 0=2E6 and we=0D=0A> did not = want to enter the unknown=2E This Mach number (I had to compute=0D=0A> it = in those early days -- no Mach displays then) was held until the=0D=0A> IAS= built to Vne (274 knots IAS) and this IAS was held to the bottom=0D=0A> of= descent, all occurring at 90-100% power=2E The maximum cruise speed=0D=0A= > at 27,000 was about 320 knots TAS (corrected for temperature and=0D=0A> c= ompressibility effects) and Mach 0=2E52=2E As I recall, it only required=0D= =0A> 200-300 feet per minute initial descent at the high power setting to= =0D=0A> drive the Mach number up to 0=2E58, so the descent started out very= =0D=0A> flat, and the built up as the air got thicker=2E I think we hit Vn= e at=0D=0A> about 12-14,000 feet and the maximum descent rate near the bott= om of=0D=0A> descent was off scale on the VSI=2E It sounded quite differen= t from=0D=0A> cruise and caused the hair on the back of the neck to stand u= p a bit=0D=0A> particularly since much of the descent was in IMC=2E=0D=0A>= =0D=0A>=0D=0A>=0D=0A> Key point for you IVP guys: It does not take much nos= e down high=0D=0A> altitudes and high power settings to push you up to Mmo,= the maximum=0D=0A> allowable Mach number=2E=0D=0A>=0D=0A>=0D=0A>=0D=0A> Y'= all be careful out there=2E=0D=0A>=0D=0A>=0D=0A>=0D=0A> Fred=0D=0A>=0D=0A>= =0D=0A>=0D=0A=0D=0A=0D=0A=0D=0A--=0D=0AFor archives and unsub http://mail= =2Elancaironline=2Enet:81/lists/lml/List=2Ehtml=0D=0A=0D=0A=0D=0A=0D=0A=0D= =0A=0D=0A--=0D=0AFor archives and unsub http://mail=2Elancaironline=2Enet:8= 1/lists/lml/List=2Ehtml=0D=0A=0D=0ACONFIDENTIALITY NOTICE: This email trans= mission may contain information that is proprietary, privileged, and/or con= fidential and is intended exclusively for the person(s) to whom it is addre= ssed=2E This communication represents the originator's personal views and = opinions, which do not necessarily reflect those of Century Bank & Trust=2E= This email and its attachments are believed to be free of any virus or def= ect, but it is the responsibility of the recipient to ensure that this is t= rue=2E Century Bank does not accept responsibility or liability for any lo= ss or damage arising in any way from the receipt or use of this email or fo= r any errors or omissions 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