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Re: Europa-List: multiple trim switches solution is not always a relay

Subject: Re: Europa-List: multiple trim switches solution is not always a relay
From: houlihan <houlihan@blueyonder.co.uk>
Date: Thu, 12 Jun 2014 11:22:18
Hi Richard.

I have a Matronics governor fitted in my Europa , its been flying for 12
years now, The governor was fitted prior to first flight and I provided the
documentation to the then PFA to support the fitting of this unit. Frances
Donaldson then approved its fitting subject to a report from the pilot who
carried out the test schedule stating that the position of the trim switch
did not cause problems, I recall Frances asking why I wanted to fit this
device and my answer that  A, I wanted speed control and B, I wished to
mount the second switch so that it was fore and aft so that pushing forward
caused nose down etc , must have been acceptable and it was then formally
permitted.

I wonder what has changed in the meantime, though in general I agree that
simple is usually best and if if something is not fitted it will not fail
in the future so if you don't need it don't fit it and that is usually also
the lighter option..

regards

Tim
G-BZTH


On 12 June 2014 10:44, Sky Mail <richard.churchill-coleman@sky.com> wrote:

> richard.churchill-coleman@sky.com>
>
> Rowland
>
> I recently investigated using a Vertical Power system as the relay and
> speed controller for my elevator trim servo with stick top switches, with
> some advice from Tony Kay.  In brief, Tony spoke to Andy Draper who
> confirmed that, due to the critical nature of the trim on an all-moving
> tailplane such as the Europa, the LAA wouldn't sanction any electronic
> controller/device in the trim circuit between the trim switch and the
> servo, in case of failure.  I believe the RAC relay deck is ok because it
> switches the power but doesn't try to electronically control it.
>
> On that basis, would this unit be permitted - I'm not sure where it goes
> in the circuit?
>
> Richard CC
>
> > Its primary function is to allow for the trim servo speed to be adjusted
> - I understand some folk have found the natural speed of the servo too high
> for their liking - but as bonus you can add as many extra trim switches as
> you want. (eg one on the panel and one on each stick-top.) I have fitted
> one to my trim circuit and in my tests so far (not yet flying) I find it is
> entirely satisfactory. In the picture of my panel (I posted a link to it
> yesterday) the small hole at bottom left adjacent to the trim switch is for
> screwdriver adjustment of the trim speed.
> >
> > in friendship
> >
> > Rowland
> >
> > | Rowland Carson
>
>


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