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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.
As has been stated already, there are numerous potential reasons for failure as speed is increased. One that I haven´t 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´t feed the worms,
Rob
-----Original Message-----
From: Wolfgang <Wolfgang@MiCom.net>
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
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’s 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’re unlikely to find one of these people willing to offer a “back of the hand” 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
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Yes, there was extensive information published here about the Vne determination.
Scott Krueger
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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.
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