Svein,
Interesting to hear you concern. When I was building my 'Classic' about
9 years ago now I was with Kim Prout
in LA, USA looking at his finished aircraft. His father was there also,
retired aerodynamicist with McDonnell Douglas, and
his comment regarding the aileron was there was a definite need for an
extra middle hinge located slightly closer to the inner hinge.
I incorporated this straight away and there has been no flexibility you
talk of, nor wear.
So your additional third hinge is needed and should solve your problem.
Cheers,
Tim
Tim Ward
12 Waiwetu Street
Fendalton,
Christchurch
NEW ZEALAND
PH 0064 3 3515166
MOB 021 0640221
ward.t@xtra.co.nz
----- Original Message -----
From: Sidsel & Svein Johnsen
To: Europa List
Sent: Wednesday, October 22, 2008 7:38 PM
Subject: Europa-List: Aileron hinge wear
On the two Europa XS's in Norway with more than 20 hours flying time,
the outer hinge on both ailerons on both aircraft has developed
noticeable wear. When the ailerons were mounted, no play was noticed -
not-perfect alignment of the two hinges removed the play that exists in
these MS-hinges even when new. The ailerons were carefully balanced
after filling and painting, as per the BM.
No wear is noticed on the inner aileron hinges, nor on the rudder or
trim tab hinges.
We have both monitored this carefully, without discovering any
increased play over the roughly 50 + hours flown since first discovering
this. However, this does not rule out that wear may continue at a low
rate.
The outer hinge is fitted a fair distance from the tip. Even with
tight outer hinge, the tip may be moved easily up or down without
applying much force due to the flexibility of the aileron's structure.
Could the cause of this be small vibrations in the outer, unsupported
part of the aileron when activating the aileron (i.e. not streamlined
aft of the wing)?
Even if the outer hinges were tight, the flexibility "does not look
right". I have not found any other aircraft design at my local field
where the ailerons flex like this.
I have now fitted an additional, third hinge on each aileron, at the
tip and of the same type and length as the original outer hinge (which I
have left in place).
Anyone else with similar experience?
Svein
LN-SKJ
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