Nigel,
Would there be any problem with doing this with 3/8 bolts on an
aircraft which had Mod 62 already done to it?
This is such an appealing idea I think.
Willie
On 25 Jun 2007, at 11:29, Nigel Graham wrote:
> <nigel_graham@btconnect.com>
>
> Hi Graham,
>
> FYI - I am working with Ian Rickard at the moment to document
> exactly what I
> did and present this to the PFA.
>
> To enlighten those of you not familiar with this mod:
> A long time ago I identified the inherent shortfall with the TP14
> method of
> securing the drive arms to the torque tube. Merely replacing these
> pins with
> oversized pins would not in my opinion, cure the problem - only
> delay the
> next re-occurrence once play developed.
>
> I developed a simple arrangement (KISS technology) that positively
> clamps
> the drive arms (TP9 and TP12) onto the torque tube by replacing all
> four
> TP14 pins with 1/4" x 2.125" AN bolts.
> To support the torque tube and prevent it distorting, 15mm wide
> cross-drilled discs are inserted into TP4 at each of the four
> stations.
> To spread the clamping load over a larger surface, "saddle
> blocks" (profiled
> to mate with the OD of TP9 and TP12) are fitted under the bolt head
> and
> castellated nut.
>
> The beauty of clamping is that it introduces a torque damper into
> the drive
> system - eliminating the shock "chattering" that wears the standard
> TP14
> pins and elongates the holes - and it can be retrofitted to tubes
> with worn
> holes.
>
> Nigel (The other one) Graham
>
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com]On Behalf Of Graham
> Singleton
> Sent: 25 June 2007 00:25
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Tailplane flutter
>
>
> <grahamsingleton@btinternet.com>
>
> Carl
> The torque tube is chrome plated 4130 I believe, stainless isn't
> strong
> enough.
> You may have spotted the weakest link in the chain, if the TP9 & 12
> had
> more bearing area the slop problem might go away. Wouldn't be much
> weight penalty either.
> OTH clamp bolting as Nigel Graham did years ago might be the best
> answer.
> Graham
>
>
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