Im not saying we shouldnt be concerned about the amount of slop in the
tailplanes. The PFA's current limit of 1/2 inch would seem to be reasonable.
We checked ours last week - as soon as we recieved the PFA bulletins and
found 3/8" movement between the tailplanes and a total of 5/8" movement when
the counterbalance arm was locked against the top fuselage stop and both
tailplanes moved up and down (hope that makes sense). Note - the second
measurement is not a requirement of the original 1999 PFA bulletin though it
goes on to say that no play is acceptable between TP04 an TP09.
We promptly installed Mod 62 and have concluded that the original 1/4" pins
had probably always been a loose fit - either due to poor manufacture or
installation. Unfortunately 13 years ago when we were building the aircraft
we didnt understand the implications of loose fitting pins.
The aircraft had its annual in March and we did the dive to 150kts twice -
once with Andy Draper at the controls and once with me. Im sure if anything
had been amiss Andy would have noticed. We also did a series of stalls and
incipient spins and again no problems were found.
One point I would mention is that there is no official Annual Inspection
checklist for the Europa fuselage (as far as I am aware) and I believe this
issue should be addressed. The current regime relies on the owner and
inspectors vigilance in noticing defects and potential problems. Some
inspectors will have more experience with Europa related issues and others
less so.
And before anyone jumps to conclusions, I should make it clear that Andy
Draper did not conduct the annual inspection - only the test flight. The
annual inspection was none the less a thorough one.
So the business of tailplane flutter is a bit of a mystery.
----- Original Message -----
From: "William Harrison" <willie.harrison@tinyonline.co.uk>
Sent: Tuesday, June 26, 2007 10:02 AM
Subject: Re: Europa-List: Tailplane Flutter
> <willie.harrison@tinyonline.co.uk>
>
> 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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>>> <pre><b><font size=2 color="#000000" face="courier new,courier">
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>>> href="http://www.matronics.com/Navigator?Europa-List";>http://
>>> www.matronics.com/Navigator?Europa-List</a>
>>> href="http://forums.matronics.com";>http://forums.matronics.com</a>
>>>
>>> </b></font></pre>
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