Carl
Having flown around, at least for a short while, in a Europa with 1"
of slop at the stab trailing edges (* see also below), without any
sign of flutter, I tend to agree that slop of itself might not be a
DIRECT cause of flutter in a Europa tailplane. However, could it
have been an INDIRECT cause: would you not agree that increasing
"wear" in the TP12/TP4 joint could lead to a TP6 failure (via undue
torsional loads going through the pip pin)? Having said that, I am
aware that we are speculating about really happened and why, although
some very strong hints are emerging already (PFA's invitation to us
to propose anti-wear joint designs, and the focus on the pip pin recess)
* In my case, the slop was not due to wear but due to bad manufacture
(he aircraft had total time of 12 hours when I bought it). If you can
believe the paperwork, it had also been tested to Vne on two
occasions in the previous 12 months when most or all of the 1" slop
was present. Makes you think.
Willie
On 26 Jun 2007, at 08:53, Carl Pattinson wrote:
> <carl@flyers.freeserve.co.uk>
>
> For what its worth, I believe the cause of this accident has
> nothing to do with "wear" in the tailplane assemblies. I base my
> "theory" on the simple fact that many Europas have flown many
> flying hours with no reported evidence of tailplane flutter.
>
> Wear and tear is a fact of engineering life and the current Mod 62
> seems to be as good a design as any. Reports from the field
> suggest that with Mod 62 done properly, subsequent wear is
> minimal. Undoubtedly there are potentially better designs out
> there - hindsight is a wonderful thing.
>
> My other concern is that changing a reasonably good design could
> move the problem elsewhere - how much damage is being done by
> builders kneeling in the back end of their fuselages - the push/
> pull tube is very vunerable and simply cant be removed.
>
> It seems more likely IMHO that there was a failure was due to the
> separation of one of the tailplanes for reasons which have already
> been discussed. Tailplane flutter may well have occurred when the
> tailplane disengaged the drive pins but this would not be
> attributable wear in the system. The PFA's current interest in the
> design of the pip pin recesses would lend weight to this possibility.
>
> Till we have the full findings of the AIIB we shouldnt be
> redesigning the aeroplane based on such limited evidence (I know
> the PFA have asked for our feedback on this).
>
> I would hope that before changing the design the PFA or Europa will
> conduct a survey amongst the current Europa fleet to establish if
> wear in the torque assembly (post Mod62) is a genuine problem or a
> myth. My understanding is that such a survey has not as yet been
> done - either by tha PFA or by the factory, though no doubt the
> recent sales figures of Mod 62 kits will give them a better idea.
>
> Carl Pattinson
> G-LABS
>
>
> ----- Original Message ----- From: "William Harrison"
> <willie.harrison@tinyonline.co.uk>
> To: <europa-list@matronics.com>
> Sent: Monday, June 25, 2007 3:24 PM
> Subject: Re: Europa-List: Article on flutter, now attached
>
>
>> Dear All
>>
>> Many thanks to Martin Le Poidevin at Flyer Magazine for letting us
>> distribute the article on flutter, which is now attached. It is PDF
>> and may be easier to read if you print it.
>>
>> The link to their website incidentally is: www.flyer.co.uk
>>
>> Willie Harrison
>>
>>
>
>
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