Dear All
Can anyone tell me why finite backlash is permitted between the TR4
torque tube and the TP12 drive flanges, but none is permitted between
the mass balance assembly and the torque tube?
Surely backlash anywhere in the chain between the mass balance and
the tailplanes is equally undesirable from a flutter viewpoint? Or,
looked at from the other way, if there is a finite amount of backlash
allowable consistent with anti flutter behaviour, then why can this
not be distributed as a "backlash budget" amongst all the links in
the chain?
Have I missed something? Because if not, I suspect an awful lot of UK
Europas are going to get grounded pending what may be an unnecessary
and painful "repair" to the TP9 horn attachment. (In all the
circumstances, don't expect any flexibility from your inspector in
interpreting the document...)
Incidentally, the 1/2" drive flange backlash, (measured at the
tailplane trailing edges), as specified in the Safety Bulletin, is a
lot more than the 3/16" limit which I recall being told by Europa 3
years ago. Can anyone shed light on that?
Willie Harrison
On 20 Jun 2007, at 16:58, Mike Gregory wrote:
> To all Listers
>
> Please see the updated safety bulletin on the PFA web site ' see
> link below.
>
> Mike
>
> Europa Club Safety Officer
>
> EUROPA SAFETY ALERT UPDATE!
>
> EUROPA SAFETY BULLETIN RAISED TO ISSUE 2 TO INCLUDE FURTHER
> GUIDANCE ON ACCEPTANCE DESIGNS OF PIP-PIN RECESSES IN TAILPLANES.
>
> Europa Flight Safety Bulletin 006
>
> ========================
> ========================
>
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