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Dive to Vne
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UVTReith(at)aol.com
Guest

Posted: Thu Sep 20, 2007 12:50 am Post subject: Dive to Vne

Michael,

  

 That's correct.

  

 Herzliche Grüße aus Deutschland,

 Bruno

     [quote][b]

europa flugzeug fabrik

Joined: 13 Feb 2006
Posts: 65
Location: North Coast, USA

Posted: Thu Sep 20, 2007 6:46 am Post subject: Re: Dive to Vne

I don't understand this one.  How does the PFA know to what speed you did the test?  If there's no enforcement mechanism, this is ludicrous.  I cannot think of any gov't requirement here where we must certify the unprovable and the authorities are perfectly OK with that.



Fred F.

wdaniell(at)etb.net.co
Guest

Posted: Thu Sep 20, 2007 8:04 am Post subject: Dive to Vne

Ah thanks now I get it next question   

It seems at first sight a sensible thing to do – rather than trying to do it in flight.  I would be interested to know what everyone else thinks.  Of course there is always the possibility that your pride and joy breaks.  But probably better this than it breaks in the air…  

   

Is there an instruction manual on how to go about it?  

   

Can one simulate the dive to Vne? – I would assume not but perhaps some parts of it can be simulated in separate operations as it were??  

   

Will  

   

       

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Michael Grass

 Sent: Wednesday, September 19, 2007 23:06

 To: europa-list(at)matronics.com

 Subject: Re: Dive to Vne  

  

  

     

William,  

    

   

    

If you do the math:  

    

2 times 1350Kg = 2700 kg or around 5940pounds  

    

   

    

This would be about the designed max +3.8 G as specified by Europa plus about a 15 % safety factor  

    

   

    

   

    

Just guessing   

    

   

    

Michael Grass  

    

   

    

----- Original Message -----     

From: William Daniell (wdaniell(at)etb.net.co)   

    

To: europa-list(at)matronics.com (europa-list(at)matronics.com)   

    

Sent: Wednesday, September 19, 2007 10:15 PM  

    

Subject: RE: Europa-List: Dive to Vne  

  

    

   

  

Forgive my ignorance but why 1350kg…?  

Will  

       

From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of UVTReith(at)aol.com (UVTReith(at)aol.com)

 Sent: Wednesday, September 19, 2007 16:35

 To: europa-list(at)matronics.com (europa-list(at)matronics.com)

 Subject: Re: Dive to Vne  

  

  

     

Here in Germany we do not do that Vne Dive Test, we are making the static wing load test with maximum 1.350 kg laod on each wing (upside down). On the tailwing we put 100 kg on one side and 150 kg on the other side and swap that then.  

    

   

    

This is a requirement from the OUV (the German PFA).  

    

   

    

   

    

Bruno  

    

   

   	  Quote: 	
		    http://www.matronics.com/Navigator?Europa-Listhttp://forums.matronics.com 	
  

   

No virus found in this incoming message.

 9/18/2007 11:53  



 9/18/2007 11:53   	  Quote: 	
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No virus found in this incoming message.

 9/18/2007 11:53  

     

  9/18/2007 11:53

    [quote][b]

grahamsingleton(at)btinte
Guest

Posted: Thu Sep 20, 2007 10:01 am Post subject: Dive to Vne

There is a significant risk of invisible damage imho so I would not want 

to test to more than 3 G. Check for any permanent deflection unloaded 

then retest and check again that deflections remain the same.

Graham



William Daniell wrote:

[quote] Ah thanks now I get it next question

 

 It seems at first sight a sensible thing to do – rather than trying to 

 do it in flight.  I would be interested to know what everyone else 

 thinks.  Of course there is always the possibility that your pride and 

 joy breaks.  But probably better this than it breaks in the air…

 

  

 

 Is there an instruction manual on how to go about it?

 

  

 

 Can one simulate the dive to Vne? – I would assume not but perhaps some 

 parts of it can be simulated in separate operations as it were??

 

  

 

 Will

 

  

 

  

 

 *From:* owner-europa-list-server(at)matronics.com 

 [mailto:owner-europa-list-server(at)matronics.com] *On Behalf Of *Michael Grass

 *Sent:* Wednesday, September 19, 2007 23:06

 *To:* europa-list(at)matronics.com

 *Subject:* Re: Dive to Vne

 

  

 

 William,

 

  

 

 If you do the math:

 

 2 times 1350Kg = 2700 kg or around 5940pounds

 

  

 

 This would be about the designed max +3.8 G as specified by Europa plus 

 about a 15 % safety factor

 

  

 

  

 

 Just guessing

 

  

 

 Michael Grass

 

  

 

 ---

asarangan(at)YAHOO.COM
Guest

Posted: Thu Sep 20, 2007 10:17 am Post subject: Dive to Vne

Vne is not always an airframe limitation. Under FAR 23.33 (U.S. regs),

the propeller speed should remain within 110% of the max rpm at Vne. I

know that the Diamond Katana aircraft had such a Vne. It had nothing to

do with the airframe. Also, experimentals do not have to comply with

Part 23, and for that matter, I don't think there is any requirement to

even have a Vne. 



Even in the case of airframe-limited Vne, it may not be a load factor

limit. The 3.8G someone else mentioned is for Va. Vne could be, for

example, the speed at which the windows blow out; or the antennas get

ripped out. It may have little to do with wing loading.

willie.harrison(at)tinyon
Guest

Posted: Thu Sep 20, 2007 3:17 pm Post subject: Dive to Vne

or flutter?

On 20 Sep 2007, at 19:16, Andrew Sarangan wrote:



 	  Quote: 	
		   

 <asarangan(at)yahoo.com>



 Vne is not always an airframe limitation. Under FAR 23.33 (U.S. regs),

 the propeller speed should remain within 110% of the max rpm at Vne. I

 know that the Diamond Katana aircraft had such a Vne. It had  

 nothing to

 do with the airframe. Also, experimentals do not have to comply with

 Part 23, and for that matter, I don't think there is any  

 requirement to

 even have a Vne.



 Even in the case of airframe-limited Vne, it may not be a load factor

 limit. The 3.8G someone else mentioned is for Va. Vne could be, for

 example, the speed at which the windows blow out; or the antennas get

 ripped out. It may have little to do with wing loading.

craigb(at)onthenet.com.au
Guest

Posted: Fri Sep 21, 2007 7:51 pm Post subject: Dive to Vne

Just a thought, but if everyone is so concerned about VNE, Flutter etc

would it not be worth commisioning a computer modeling simulation for a few

thousand dollars, as was done with the lancair, and find all the sortcomings

in one go and be handed the solutions, if memory serves this type of

modeling

on the lancair took the theoretical max speed up to over 500kts, and the

solutions were as simple as a few extra layups of uni in the correct spots.



just a thought



I for one would pay for a share in such a study, if just to have the

knowledge i am safe at 150kts or 180kts or ..... etc

2:02 PM

josok-e(at)ukolo.fi
Guest

Posted: Sat Sep 22, 2007 1:03 am Post subject: Dive to Vne

Craigh, 

It is a gross misunderstanding that anybody should be worried about flutter, VNE etc. The Europa is a wonderfull design, and is better tested then most kit planes. I thind we are under-appreciating the lot of work that Ivan and his friends have put in to it. After that, the type has tens of thousands of flying hours without any structural problem. Most of that worrying seems te be done by folks who are not flying their plane yet. Don't! Enjoy the build, and you will enjoy the result. Your sign-off makes me frown, you can fly today if you want, rent-a-plane or so. Don't hurry the build, it leads to frustration, and you will finish building before the plane is ready.



Computer modelling is fine, maybe there are areas where improvement is possible. But i doubt it will return anything usefull for the money. 



Regards,



Jos Okhuijsen

Visit -  www.EuropaOwners.org

craigb(at)onthenet.com.au
Guest

Posted: Sat Sep 22, 2007 5:23 am Post subject: Dive to Vne

Thanks for the reply, as far as my post goes, I have no problems with flying

at VNE, When i did my licence it was mostly in a Piper Tomahawk, most tomies

are slow and predictable except for the stall, (I flew a few different ones)

but the main one had a different prop and would run through VNE in cruise

flight if you didnt watch it, which IMHO was a good thing as it meant you

had to slow down to VA if things got bumpy, so it taught you be concious of

your airspeed at all times, not just takeoff landing etc. My main reason

for suggesting the modeling was to maybe see if the VNE could be increased

at reduced MTOW. Sort of working backwards from the ultimate load of 8.55g

suggested by europa at the standard MTOW of 1300 or 1370 a reduction of

about

40 lbs would seem to suggest a new ultimate load of 9.0 g which is what is

required for a full aerobatic rating in australia of 6.0g (+50% safety

margin) which would intern mean an increase in VNE provided no flutter

issues

are a problem, which is where the computer modeling comes in. As far as the

signoff goes, dont get me wrong I am enjoying the build, seeing it grow, and

getting satisfaction from each bit i finish, but all my spare cash goes into

the plane so flying for the moment is not happening, thats why i wish it was

built, especially when we get a day thats almost calm with unlimited vis

and temps in the 20's it makes me want to be up there.



--

Richard_Pottorff(at)msn.c
Guest

Posted: Sat Sep 22, 2007 5:26 am Post subject: Dive to VNE

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  There was a Wind Tunnel column in Kit Planes magazine a few months ago  about Vne. The upshot was that you don't use indicated or calibrated airspeed to  determine Vne. You use TAS. For those of you who have to dive to Vne, if you do  your calculations ahead of time, and start high enough, you could actually reach  Vne well before you exceed the structural cruising speed.

  

 Vne is concerned with the actual speed of the air molecules hitting the  control surfaces, not the number of air molecules that hit the airplane per  second.

  

 Hope this helps.



   [quote][b]

grahamsingleton(at)btinte
Guest

Posted: Sat Sep 22, 2007 4:33 pm Post subject: Dive to VNE

Not exactly Richard,

The main issue is mass times velocity squared, so it's both speed and 

number of molecules

Viscocity comes into it too becaues flutter is a resonance issue.

Graham



Richard Pottorff wrote:



 	  Quote: 	
		    

 Vne is concerned with the actual speed of the air molecules hitting the 

 control surfaces, not the number of air molecules that hit the airplane 

 per second.

wdaniell(at)etb.net.co
Guest

Posted: Mon Sep 24, 2007 8:05 am Post subject: Dive to Vne

Thanks

Will



--

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