To Chris,
The solutions for the Mono engine hoist are obvious and not so obvious or
tollerable.
1. The easiest way to get access on the 912 XS FWF is to remove the air plenum.
Wrap a strap around the frame, make sure the spinner clears and haul away.
2. I lift at the short area between the gear frame and the isolation mount
using
a one inch strap mostly. However, I have seen two interesting ideas presented
back in or around 2000.
a. Use a 1/8 inch cable with nylon tubing over it (or was it thick heat
shrink
I couldn't tell. The cable was routed around the horizontal landing gear mount
tube at the top where the bungee resides. The cable had larger thimbles
and with two cables identically on each side, he had a small hook to engage his
lift. The plane was converted to a trigear and I've lost track of it. The
1/8 inch cables are strong enough and were left on the plane permanently. The
cables did not interfere with the lift and were just clear of the plenum box.
Problem was our original shop engine lift would not extend far enough without
hitting the spinner on his plane. What a bummer that was. We got a 40 foot
lift platform and installed a chain hoist in the shop after that.
b. The other neat idea was Jim Brown's. He used two pieces of steel strap of
1/16th inch and 1.5 inches wide. He covered the metal in thick heat shrink
and folded it around the tube just outside his bungee. He figured the steel was
.09 square inches and the steel should be 125K PSI tensile so one on each side
should work as each was 1000 pounds capable. He then put a bolt shackle through
the strap for the lift points. I don't know if he ever installed what
he made as his Rotax needed a new stator and we had to pull the engine. Once
the stator was installed I lost track of what he made at the shop for a hoist.
c. Any hoist should be well thought out and easy to use. The hoist mechanism
should be well braced and allow gear access (why I prefer a hoist trellis vs
a long arm engine hoist) for maintenance under the wheel well area. Remember
that a hydraulic engine hoist must have its legs extended well behind the hook
point or the load as you get into the plane while hoisted will be outside the
area of the base of the hoist. Use extreme caution around aircraft that are
jacked up when climbing aboard to cycle gear or do cockpit work with an aircraft
on a hoist. The CG and lift forces change dramatically.
d. Finally, a method of support is critical should the hoist fail, and the
only
jack stand position that I believe is safe for continuous use is under the
foot wells. So, fabrication is needed to build a safety stand.
e. I do not see the hydraulic motorcycle type jack stands to be usable for me
because the jack gets in the way of any work to be done in the black hole of
Calcutta wheel well. Jim Butcher has a wood hoist he uses and it takes a bit
of time to unbolt and store in his trailer but is really convenient for hoisting
his aircraft. If I had a hangar only to work in, I'd build one. It is very
stable but note the area of his floor base. It is wide for a reason.
Having a lift plan is nice if you ground loop/gear collapse/runway departure and
need to hoist the aircraft. However, the crash recovery crews may not listen
to you unless you put a large arrow saying remove cowl to access the lift point.
Many an aircraft has been nearly destroyed by crash recovery crews. They
do not understand a builder owner. You are just a dumb pilot that crashed on
their runway and they need to get the trash cleared and protect lives. OK,
sorry for the sarcasm.
Bud
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