Can anyone explain to me how the tailplane can possibly move outward by even
a millimeter when the pip pin head is resting firmly against a solid wall on
the inboard side, whether this is epoxy, glass, wood or anything else ?
Where are these huge forces that would pull this pin sideways through the
surrounding foam body ? Is a loose TP6 really such a big problem, apart from
making it difficult if not impossible to rig the tailplane ?
Regards,
Karl
>From: "Sidsel & Svein Johnsen" <sidsel.svein@oslo.online.no>
>Reply-To: europa-list@matronics.com
>To: <europa-list@matronics.com>
>Subject: Re: Europa-List: Europa Tailplane - Mod 73
>Date: Sat, 14 Jul 2007 16:54:16 +0200
>
>14 Hantone HillWhile there may be doubt whether the shallow lip on the
>inside of TP6 will be adequate as a tailplane retention, it is worth
>reading EA2004's reasoning behind Mod 73 carefully: Retention of the
>tailplane by TP6 (and the pip pin securing TP6 to the torque tube) AND a
>secondary retention by the pip pin and its surrounding composite structure
>alone, should the primary retention not hold. The mod is therefore as much
>a strengthening of the structure around the pip pin and a proper transfer
>of forces acting on the pip pin into the tailplane skin, as it is a mod for
>better bonding of TP6 to the tailplane.
>
>This is the reason why the instructions make a point of not removing any
>bid/epoxy around the hole on the underside, in the event the pip pin ball
>should not open on the underside of the new layup, but instead buy a longer
>pip pin. Removing bid/epoxy here would defeat that secondary retention
>function of the mod.
>
>As I understand it, this view is also reflected in FSB-006 Issue 3 section
>5: Mod 73 need to be done if the upper pip pin recess does not satisfy the
>stated requirements. I think, however, that PFA ought to have required
>ovalization of the torque tube holes even if Mod 73 may be omitted if the
>requirements of Section 5 are complied with -ovalization should be done in
>any event, I think.
>
>Regards,
>Svein
>LN-SKJ
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