I have one little niggle with the Mod73 as currently published. I was
under the impression that layups around 90 degree corners was to be
avoided. Glass cloth dosent like being bent around acute bends and
usually results in the glass cloth lifting and causing an air pocket. I
am referring to the glass cloth that is stippled to the sanded surface
of the tailplane.
Surely a stronger and cosmetically preferable solution would be to make
a flox corner around the underside of the tailplane surface where it
joins the top of the underside recess (or bottom if we are talking
underside - it would be at the top when being worked on). By the time
one has incorporated two layers of bid around the periphery of the
recess and then glassed over it again the surface is certain to stand
proud of the rest of the tailplane and leave an unsightly lump.
If I have the choice I would prefer to prepare flox corners where the
recess meets the tailplane surface and let the excess glass poke out of
the recess till hardened. Then slice the excess glass away with a sharp
knife till level with the tailplane surface. When the recess is finally
filled with a lump of foam and glassed over, a further flox corner could
be incorporated on the inside of the cavity (where it meets the
surface).
BTW a much more effective and simpler means of tailplane retention could
have been achieved by drilling a hole through the tailplane from top to
bottom through the root closeouts and dropping a 9" x 1/4" steel pin
behind the torque drive plates (ie through the top skin, behind the
drive plate either in front or behind the torque tube - or both and then
through the bottom skin). Alternately a hole through the centre of the
torque tube though this could have structural implications. A split pin
or ring through the underside would be needed to secure it. Washers
reduxed to the insides of the closeouts would ensure extra strength and
prevent the pin from pulling through the tailplane surface. This would
eliminate any possibility of the tailplane moving outboard during
flight.
Still, I guess its too late to consider that suggestion.
Carl Pattinson
G-LABS
To all Listers
Francis Donaldson, Chief Engineer of the UK Popular Flying Association
has asked me to give maximum publicity to the attached leaflet for Mod
73 covering tailplane retention. It will be available on the PFA
website tomorrow, and copies have been put in the post today to all UK
owners of flying aircraft, together with a covering letter and revised
FSB 006 at issue 3.
The good news is that compliance (for UK owners) is required within the
next ten flying hours or before the next permit renewal, whichever is
earlier, rather than "before next flight".
There are three steps:
1. Elongation of the pip-pin holes in the torque tube.
2. Modification of the underside of the tailplane by constructing a
reinforced pip-pin recess, except for tailplanes that are pre-moulded or
fitted with Europa Club Standard Mod 10672. Note that 10672 is not
capable of being retrofitted.
3. Placards on the top surface of each tailplane warning of the
need to ensure correct engagement of both tab drive pin and pip pin
before flight, and on the root rib of each tailplane to certify that Mod
73 has been complied with.
Fly safely
Mike
Europa Club Safety Officer
<EUROPA PFA FSB-006 issue 3.pdf>
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