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Re: Europa-List: Vne speed

Subject: Re: Europa-List: Vne speed
From: Sidsel & Svein Johnsen <sidsel.svein@oslo.online.no>
Date: Wed, 13 Dec 2006 22:29:18
All,

The reference for Vne is CAS (calibrated air speed), not IAS by 
definition.  If your ASI has been properly calibrated, you read it off 
the instrument as equal to IAS.

As to the Vne verification (not test - that's implying it's too risky), 
Andy Draper gave me this good recommendation while he was still at 
Europa's (starting with the issue of flutter test, which is NOT 
recommended):
quote

I would recommend that you do conduct a dive to Vne during your test 
flying, but only after you have calibrated your ASI.  At Vne you should 
move the stick in pitch and roll by a small amount and separately and 
also the rudder, but not necessarily tap them.  This tapping is a 
technique to try to excite flutter where there is a tendency for it to 
happen and usually need only be done when establishing the flight 
characteristics of a new design.  You will be more concerned to check 
that the forces have increased with increased speed and that there is 
still a tendency for the controls to self centre.  It would be most 
unlikely that your aircraft does not comply, as the Europa design has 
been fully tried and tested.

In the UK, this 'Vne dive' is conducted at each annual flight test.  The 
favoured technique is to fly and trim at a high cruise speed, say 130kts 
level, then progressively pitch down and reduce throttle to 
approximately 1/3 open. Carefully monitor the ASI and be careful not to 
accellerate beyond Vne.  Anticipate Vne by about 5 knots by relaxing 
forward pressure.  Don't attempt to trim for Vne.  When you relax the 
forward pressure the aircraft will revert to a climb and slow reasonably 
quickly.

unquote

Nedless to say:  No wind sheer and no turbulense when this verification 
is performed!

Best regards,

Svein

LN-SKJ


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