Zenair aircraft pedal - SB

[Wayne G. O'Shea]

Hi Gang! Just thought I should throw this one out before someone "packs it
in" and since I have known about this problem for years I would feel like
shit if I wasn't proactive and passed it on again. If someone is on a
701/601 mail list you may want to pass it on as well.

Had the customer leave his keys up under his Stab so they were handy for
both of us, after he returned from the cottage last weekend, so I could do a
few minor cooling adjustments to finish up the engine upgrade on his
Pegastol (CH701 variant). When I grabbed the keys the other day I found it
strange that his rudder cables looked loose, considering that I had just
rigged everything a week earlier when I had reinstalled his amphibs. I knew
what to look for right away, since I have welded the pedals back together on
2 other 701's over the years. Sure enough his right rudder pedal was cracked
at the angle butt weld, between the pilots pedal post and the cross tube to
the passenger pedals, and was deformed enough to allow the pilot and
passenger pedal to be torsionally misaligned letting the cable go loose (as
the right pilot pedal is held by the nose wheel push rod).

This is a problem I discussed with Chris Heinz about 4 years ago and to the
best of my knowledge the design has never been changed. The pedal assemblies
are welded together without any reinforcing straps or gussets added to the
joint. You can get away with this on a taildragger, but apparently not with
the positive steering nose wheel on the Zenair series as the pedals will not
take the load of starting to turn the aircraft while taxing (before you get
it moving forward). Especially when running the turf tires, or the amphib
gears nose wheel extension.

If you are flying a Zenair be vigilant and do a thorough inspection of your
pedal assemblies, with lots of light shining under the panel, before further
flight. If you ever notice a loose cable, don't ignore it and immediately
inspect the pedal assemblies again. This is one design that is not forgiving
when a pedal breaks off, thanks to the all flying rudder/fin (another reason
not to like it besides the ones Mike Davies mentioned in the Rec Flyer
article!). When the pedal breaks off the rudder will peg itself full to one
side and you have a couple of options. Apply full opposite stick and side
slip into the nearest cow pasture, OR If the left pedal breaks off reach
down and pull the cable tight with your left hand to center the rudder and
fly the plane to the next landing area. If the right pedal breaks off, get
your foot WAY over on the passengers right pedal or get you passenger to do
so for you and land at first opportunity!

Remember, if something doesn't look right, or sound right, it isn't!!

Safe flying ladies and gentlemen,
Wayne G. O'Shea
Life #533





-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------