Nigel,
I can follow your explanation except when you write: "What is dangerous is
if the taiplanes move outwards allowing them to disconnect the TP10 pins."
TP10's are nylon tubes. You mean perhaps the pins on the TP12?
The pip pin recesses on F-PKRL were made conform the build manual, even
stronger.
The problem I would talk about is the play between TP12 and TP4.
TP4 and TP12 are delivered with holes. When you have to fix them together
with the nylon TP10 tubes then you have to drill very carefully to allow the
clevis pins to be installed. Afterwards I found that the play occured on
starboard side by moving the TP12 by the pins. The mass balance keeps the
TP4 easily in place. So port side no play. When I did the same test on Dirk
Oyen's OO-145, it gave the same result. Factory tolerance? Bigger holes and
clevis pins wasn't a solution (Rowland Carson). Others do have the same
problem hence the discussions: clamps or taper pins. Finally no definite
solution nor mandatory modification. The play measured at trailing edge may
not be more then 1/2". I will have no play at all. So if we are waiting for
a modification to keep a fluttering tailplane on board then I say: You treat
the symptom and not the illness.
Karel Vranken, F-PKRL waiting for next mod and if my problem is not
concerned then Bob Harrison may have an order from me.
----- Original Message -----
From: "nigel charles" <nwcmc@tiscali.co.uk>
Sent: Thursday, June 21, 2007 11:45 AM
Subject: RE: Europa-List: RE: EUROPA PIP-PIN RECESS
>
>>This is like treating the symptom and not the illness. The play comes
> from
> the TP10 fixing on the torque tube. If the pip pin fixes well, the play
> is
> tranferred on the glue of the TP6 in the foam! If there is any flutter
> then
> you can imagine how long it will take before the TP6 comes untie.<
>
> I agree that the problem starts with the fixing of the TP10's. However
> the design of the pip pin recess is still important. A small amount of
> relative movement between the tailplanes (caused by the less than
> perfect fixing of the TP10's) is not in itself dangerous. Neither is
> disbonding of the TP6's by itself. What is dangerous is if the
> tailplanes move outwards allowing them to disconnect from the TP10 pins.
> If the TP6 becomes disbonded (by for instance twisting loads) it is
> possible in some cases for the tailplane to move outwards sufficiently
> for the tailplane to become disconnected from the TP10 pins. The size
> and shape of the recess is important in this respect. A recess sidewall
> which is close to the pip pin head on the inboard side can prevent
> outward movement of the tailplane whilst the pip pin is in place even if
> the TP6 is disbonded.
>
> Although flutter has been mentioned (and can be a very dangerous
> condition), a possible cause of this inflight loss of control is a
> tailplane moving outwards enough to become detached from its TP10 pins.
> Regardless of the TP10 fixing it is important that this is not allowed
> to happen.
>
> I know that the PFA is looking at a modification to the pip pin recess
> so we will just have to wait to see what they come up with.
>
>
> Nigel Charles
>
>
>
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