The trim enable switch, as shown in Europa's diagram, enables the trim readout
as well as movement. Since the trim is connected directly to the battery,
leaving the trim enabled will cause a continuous drain on the battery due to
activation of the readout. Why is the trim not disabled by the master switch?
Is this to leave the trim enabled when the master is turned off prior to an
emergency landing? Why not connect the trim readout via the flight instrument
breaker instead to avoid inadvertently loading the battery?
I plan to mount the trim switch on the stick, with the enable switch next to
the trim indicator. I am unclear on how the trim enable switch should be used
to prevent trim runaway, so I got a double throw switch with momentary on one
side, center off, latch on the other side. This way the enable switch can be
latched on and the stick mounted switch used for trim or alternatively the
enable switch can be pressed to allow use of the stick mounted switch, thus
disabling the stick mounted switch most of the time. This amounts to putting
off the decision on how to use the trim enable switch until I see how it works
out in practice -- suggestions anyone?
Once this trim enable switch was selected, another idea occurred: connect a
zener in one side so that in one of the positions the voltage and thus the
trim speed is reduced. Seems like a reasonable thing to want based on
comments offered on the sensitivity of the Europa's trim. Question: should
the lower speed be on the momentary or latching side?
Regards, John A044 Newtown, CT
|