X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 15 Dec 2009 13:03:58 -0500 Message-ID: X-Original-Return-Path: Received: from bay0-omc1-s6.bay0.hotmail.com ([65.54.190.17] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTP id 4021911 for lml@lancaironline.net; Tue, 15 Dec 2009 13:00:43 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.190.17; envelope-from=randystuart@hotmail.com Received: from BLU0-SMTP4.blu0.hotmail.com ([65.54.190.61]) by bay0-omc1-s6.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 15 Dec 2009 10:00:03 -0800 Received: from mail pickup service by BLU0-SMTP4.blu0.hotmail.com with Microsoft SMTPSVC; Tue, 15 Dec 2009 10:00:03 -0800 X-Originating-IP: [99.163.183.180] X-Originating-Email: [randystuart@hotmail.com] X-Original-Message-ID: X-Original-Return-Path: randystuart@hotmail.com Received: from laptop ([99.163.183.180]) by BLU0-SMTP4.blu0.hotmail.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.3959); Tue, 15 Dec 2009 09:59:58 -0800 From: "Randy" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: Vne discussion X-Original-Date: Tue, 15 Dec 2009 09:59:07 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_005F_01CA7D6D.3DFB7F40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-OriginalArrivalTime: 15 Dec 2009 17:59:59.0666 (UTC) FILETIME=[6B049920:01CA7DB0] This is a multi-part message in MIME format. ------=_NextPart_000_005F_01CA7D6D.3DFB7F40 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable I think this is an unanswerable question. There is no doubt that Lance = and his designers did all the calculations on every plane he kitted but = what did he make those calculations on?? The kits are not shipped built = so a portion of the calculations Lancair would have to consider is the = builders ability and materials used. With that in mind there could be a = big difference in the high numbers to the low numbers. Since the = Lancair's seem to be pretty stout, for the most part, Lancair must have = put a large margin in his calculations to consider the worst case. If = that's the case, it makes me wonder what his numbers REALLY where, not = what he prints in the POH.=20 A certified, "factory built" aircraft would have set numbers on set = calculations since the building process and materials would be pretty = consistent. Then add the safety margin. There are so many variables on a = kit aircraft I don't know how you could have any set numbers on a = specific Lancair, only set numbers on the parts themselves.=20 I'm sure someone out there in Lancair land knows how these were derived = and what ALL the numbers were. It would be interesting to see the real = numbers. Randy Stuart LNC-2 ----- Original Message -----=20 From: rehbinc@aol.com=20 To: lml@lancaironline.net=20 Sent: Tuesday, December 15, 2009 5:41 AM Subject: [LML] Re: Vne discussion If you really want to know the answer, you should ask Lance or the = engineer(s) responsible for the analysis. Unless one is privy to the = calculations and testing done on the airframe, there is no way of = providing you with a credible answer to your question.=20 As has been stated already, there are numerous potential reasons for = failure as speed is increased. One that I haven=C2=B4t seen mentioned is = aerodynamic heating and this is a speed limit on at least one miltary = jet as the canopy melts above this speed. Another is wing wake = inteference with the horizontal stabilizer, which was an issue with the = P38. This is typically a mach related issue. The list is quite = extensive, and while many of the possible limiting factors may be = unrealistic for the 300 or Legacy there are still many that may be = applicable. Without being familliar with the analysis of these planes, = it is impossible to know what the critical limiting factor was in the = assigning Vne. While it may be pleasing to know the answer for accademic reasons, = what else would you do with the information? Alter the structure to = increase Vne? Can you analize the modification to determine its = effect(s) upon the other parameters than the one you are trying to = improve? In other words, will your fix actually reduce Vne? This can get = very deep very fast. Don=C2=B4t feed the worms, Rob -----Original Message----- From: Wolfgang To: lml@lancaironline.net Sent: Mon, Dec 14, 2009 7:18 pm Subject: [LML] Re: Vne discussion I'm having difficulty understanding why no one can give direct = answers. I'm only looking for the various factors that are used to determine = Vne. Flutter, canopy being sucked off, skin surface excess vibration . . . = ? ? ? . . . not the explecit calculations. Let's narow it down, what factors for the 300 series and Legacy ? Wolfgang =20 -------------------------------------------------------------------------= ----- From: "Robert Pastusek" =20 Sender: =20 Subject: RE: [LML] Re: Vne discussion=20 Date: Sun, 13 Dec 2009 17:37:39 -0500=20 To: lml@lancaironline.net=20 Wolfgang, As has been stated a number of times on this forum, the determination = of Vne is a very complex and multi-discipline task. Not to repeat = what=E2=80=99s been said many times, the several aero engineers that = participate in this forum have suggested that this subject is probably = beyond a basic aero engineering degree. You=E2=80=99re unlikely to find = one of these people willing to offer a =E2=80=9Cback of the = hand=E2=80=9D quick solution. LOTS of information on the internet about = this subject, and some serious reading available. a couple of courses on = aeronautical design and finite element analysis will give you some idea = of what you are looking for. Definitely beyond a simple posting on the = LML, IMHO. Bob=20 -------------------------------------------------------------------------= ----- From: Sky2high@aol.com=20 Sender: =20 Subject: Re: [LML] Re: Vne discussion=20 Date: Sun, 13 Dec 2009 17:37:27 -0500=20 To: lml=20 =20 =20 =20 Yes, there was extensive information published here about the = Vne determination. Scott Krueger=20 -------------------------------------------------------------------------= ----- So . . . am I to conclude that there's nobody on the list that can = identify how Vne is determined ? With all the experience of posters on this list, I'm surprised to say = the least. Is this black magic art or is there some real formula/procedure ? All I've seen here so far is "is that meadured in IAS, TAS OR Mach ?" = or "what is the speed for xxx airframe ?". . . . but nothing about how the number comes to be. Wolfgang ------=_NextPart_000_005F_01CA7D6D.3DFB7F40 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
I think this is an = unanswerable question. There is no doubt that Lance and his designers = did all=20 the calculations on every plane he kitted but what did he make those=20 calculations on?? The kits are not shipped built so a portion of the=20 calculations Lancair would have to consider is the builders ability and=20 materials used. With that in mind there could be a big difference in the = high=20 numbers to the low numbers. Since the Lancair's seem to be pretty = stout,=20 for the most part, Lancair must have put a large margin in his = calculations to=20 consider the worst case. If that's the case, it makes me wonder what his = numbers=20 REALLY where, not what he prints in the POH.
A certified, = "factory built"=20 aircraft would have set numbers on set calculations since the building = process=20 and materials would be pretty consistent. Then add the safety margin. = There are=20 so many variables on a kit aircraft I don't know how you could have any = set=20 numbers on a specific Lancair, only set numbers on the parts themselves. =
I'm sure someone = out there in=20 Lancair land knows how these were derived and what ALL the numbers were. = It=20 would be interesting to see the real numbers.
 
Randy=20 Stuart
LNC-2
----- Original Message -----
From:=20 rehbinc@aol.com=20
Sent: Tuesday, December 15, = 2009 5:41=20 AM
Subject: [LML] Re: Vne = discussion

If you really want to know the answer, you should ask Lance or = the=20 engineer(s) responsible for the analysis. Unless one is privy to the=20 calculations and testing done on the airframe, there is no way of = providing=20 you with a credible answer to your question.
 
As has been stated already, there are numerous potential reasons = for=20 failure as speed is increased. One that I haven=C2=B4t seen mentioned=20 is aerodynamic heating and this is a speed limit on at least one = miltary=20 jet as the canopy melts above this speed. Another is wing wake = inteference=20 with the horizontal stabilizer, which was an issue with the P38. This = is=20 typically a mach related issue. The list is quite extensive, and while = many of=20 the possible limiting factors may be unrealistic for the 300 or Legacy = there=20 are still many that may be applicable. Without being familliar with = the=20 analysis of these planes, it is impossible to know what the critical = limiting=20 factor was in the assigning Vne.

While it may be pleasing to = know the=20 answer for accademic reasons, what else would you do with the = information?=20 Alter the structure to increase Vne? Can you analize the modification = to=20 determine its effect(s) upon the other parameters than the one you are = trying=20 to improve? In other words, will your fix actually reduce Vne? This = can get=20 very deep very fast.
 
Don=C2=B4t feed the worms,
 
Rob
-----Original=20 Message-----
From: Wolfgang <Wolfgang@MiCom.net>
To:=20 lml@lancaironline.net
Sent: Mon, Dec 14, 2009 7:18 pm
Subject: = [LML] Re:=20 Vne discussion

I'm having difficulty understanding why no one can give direct=20 answers.
I'm only looking for the various factors that are used to = determine=20 Vne.
Flutter, canopy being sucked off, skin surface excess vibration . = . ? ?=20 ?
. . . not the explecit calculations.
Let's narow it down, what factors for the 300 series and Legacy = ?
 
Wolfgang

 
=
From: "Robert Pastusek" <rpastusek@htii.com>
Sender: <marv@lancaironline.net>
Subject: RE: [LML] Re: Vne discussion
Date: Sun, 13 Dec 2009 17:37:39 = -0500
To: lml@lancaironline.net
Wolfgang,
As has been stated a number of times on = this forum,=20 the determination of Vne is a very complex and multi-discipline task. = Not to=20 repeat what=E2=80=99s been said many times, the several aero engineers = that=20 participate in this forum have suggested that this subject is probably = beyond=20 a basic aero engineering degree. You=E2=80=99re unlikely to find one = of these people=20 willing to offer a =E2=80=9Cback of the hand=E2=80=9D quick solution. = LOTS of information on=20 the internet about this subject, and some serious reading available. a = couple=20 of courses on aeronautical design and finite element analysis will = give you=20 some idea of what you are looking for. Definitely beyond a simple = posting on=20 the LML, IMHO.
Bob=20
From: Sky2high@aol.com
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: Vne = discussion
Date: Sun, 13 Dec 2009 17:37:27=20 -0500
To: lml

 
Yes, there was extensive information published here about = the Vne=20 determination.
 
Scott Krueger
So . . . am I to conclude that there's = nobody on=20 the list that can identify how Vne is determined ?
With all the experience of posters on = this list,=20 I'm surprised to say the least.
Is this black magic art or is there some = real=20 formula/procedure ?
All I've seen here so far is "is that = meadured in=20 IAS, TAS OR Mach ?" or "what is the speed for xxx airframe=20 ?".
. . . but nothing about how the number = comes to=20 be.
Wolfgang
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