Please see below Francis Donaldson's e-mail to Ted Gladstone, as advised in
my e-mail to the forum a few minutes ago.
In the interest of space, I have deleted Alan Simmons' agreement to the
issue of this e-mail.
David
_____
From: Francis Donaldson [mailto:francis.donaldson@pfa.org.uk]
Sent: 27 July 2007 10:33
Cc: Andy Draper
Subject: RE: Europa statement
Dear Alan
Following our discussion I have decided not to issue a PFA statement about
the Europa accident, for the reasons you suggested. However instead I would
like your agreement to sending the e-mail below to individuals who e-mail us
speculating about the accident sequence. Is this OK ?
Francis Donaldson
Dear Ted
Thanks for the copy e-mail. The reason why the rear wing pin pulled out of
the right wing was almost certainly because the construction of the hard
point in the root rib was defective, the laminations of the plate were
staggered so that the threaded hole was not through the middle of the metal
plates as designed. It was near the edge of the first one and penetrating
the edge of the underneath ones, ie only the first laminate would have been
able to carry significant load. This is why the outer laminate ripped out.
I think that release of the rear wing attachment allowed the right wing to
swing forward and split the right wing spar, causing the right wing to break
up and tearing the pins out retaining the other wing in the process. The
massive jerk caused by the wing failure would explain what moved the right
tailplane off its pitch pins and allow it to flutter and depart, and the
left tailplane could have fluttered and then departed because in moving
outboard, the right tailplane had dragged the anti-balance tab operating
tee-bar off the pin on the left tailplane's anti-balance tab.
Had the main wing pins failed, there would not have been the massive damage
to the right wing which occurred, as failure of the pin would immediately
off-load the wings.
Both crew were found with the cockpit wreckage, there was no question of
either falling out of the aircraft in flight.
We are taking what we see as appropriate steps to allow the Europa fleet to
carry on flying, with a acceptable level of safety. If we wait for the AAIB
report to be published in full, we would have to ground the fleet meanwhile,
which could last many months.
The work on the root pin attachment does not involve a huge amount of work
or a massive hole in the skin, Andy has managed to devise a keyhole surgery
approach. It has been tried on a sample Europa and went OK.
Please note that the above is our present line of thought about the accident
sequence but is not yet definitive, that will be the prerogative of the AAIB
and their final report. There is further testing to be done to test the
theory, which we are helping AAIB to prepare. Please do not broadcast the
above on the Europa net or elsewhere as it would not be appropriate to
promulgate the present theory in advance of the AAIB report.
Best regards
Francis Donaldson
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