John, sorry to hear about the accident. Thanks for sharing this
unpleasant event. I hope you are able to get her flying once again.
Regarding the throttle cables I am using a solid wire vs stranded cable.
I too had concerns about the cable kinking and thought the wire is
effective in either push or pull. I don't recall at the moment but I
ordered the cable from Aircraft Spruce. I did have to make up custom
ends but this wasn't difficult as I bent the wire around an AN111 cable
bushings and soldered it in place as a extra measure of safety, rather
easy. The cable end is then attached to the throttle lever via the
mounting hardware for the Europa supplied cable. I have yet to fly as I
am still months away from completing my plane. But the system works well
on the ground.
Erich Trombley
A028
writes:
>
> I recently had a landing accident in N44EU which was
> precipitated by power failure during a go around; N44EU, a Mark
> 1, incurred "substantial damage" (FAA assessment). I was
> fortunate to walk away with minor bruises and scratches.
>
> In analyzing the accident later, I concluded from all the
> details of the power failure that the most likely cause was that
> the throttle cables kinked within the throttle block when I
> attempted to rapidly apply full throttle, effectively locking the
> power at the existing setting.
>
> With the throttle at idle, several inches of cable are within the
> throttle lever block and are not constrained by the sheath. When
> the throttle is advanced, the springs at the carburetors normally
> take up slack in the cable. Should the throttle lever be
> advanced faster than the springs take up the slack, the cable can
> loop downwards and kink within the throttle lever block,
> effectively locking the throttle at a setting providing much less
> than commanded power.
>
> I expect that the rate at which the springs can take up the slack
> will vary between aircraft depending on the routing of the
> throttle cables, cable lubrication, and any other friction or
> mass in the throttle cable system. In my case, I used powdered
> graphite lubricant on all cables rather than oil (this to avoid
> dirt attracted by oil) - I doubt that this contributed to the
> problem, but each builder must make a choice of lubricant for
> himself. The awkward part is that dirt, temperature, and other
> unknown conditions could affect the maximum rate of throttle
> application before kinking will occur and this could vary between
> flights. Further, rapid throttle application tends to occur when
> power is needed rapidly so a pilot could exceed the critical rate
> inadvertently.
>
> A further consideration with this throttle system design is that
> should one of the throttle springs break then a similar kinking
> failure will almost certainly occur.
>
> My understanding of the reason the spring is incorporated by
> Rotax is to cause the engine to go to full power should a
> separation occur within the throttle linkage, the concept being
> that having full power is better than having less.
>
> My inquiries turned up another report of a Europa which kinked a
> throttle cable on takeoff resulting in less than full power and
> an aborted takeoff with no serious consequences. This lends at
> least a bit of credibility to my amateur accident investigation.
>
> I don't know whether the XS model uses the same throttle design
> so this may not apply there.
>
> Until the cause is officially established, I believe Europa
> builders who have throttles of the above described design should
> use some care when advancing the throttle rapidly.
>
> John Newtown, CT
>
> The Europa List is supported by Aviators Network UK -
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