Hi Ira
"If a way to restart by air has been found as Terry
says, that is a greatadvance in my knowledge!"
I
don't have any experiance with 912S, but with your ability to select
course pitch on Airmaster, and ability to pitch nose at groundand
quite easily select an airspeed in excess of 110knots, I have a hard time
trying to figure that a combination offine pitch (high
gear)and fairly mild compression ratio(compared to a high
performance motor) will not airstart a 4 cylinder motor with ~300CCs per
cylinder. This takes into consideration gearbox, but also fairly large fan
up front which is a pretty good force to be reckened with in hurricane
speed wind. Course pitch of proppseudo equates to a higher ground
pounding transmission gear when bump starting. The hardest motor I ever
encountered on a motorcycle trying to bump start was an all out road
racingCageva with a 2 cylinder Ducati engine with a compression
ratio that was beyond high. Probably 500ccs per cylinder that absolute
needed racing fuel octane.Several guys and top gear would in fact do
the deed which is pretty amazing. This bike wouldn't think about idling
below 3500RPM. The only thingI don't like about air starting a Rotax
is once motor begins to spin up, it's going to go from stopped with no oil
pressure to quite fast almost instantly. If you have cold thick oil on top
of having a lot of oil drain away, that is not going to be a secret to
long engine life. For a back up meansof starting motorif
starter will not do deed, this would be agood procedure to have
figured out and information stored inyour back pocket. Would you be
interested in taking me for a ride over Brookhaven for a mission? We go up
to 7500 or higherfeet over airport,I will bring my variometer
and we can shut off motor and test glide angle and sink rates with various
configurations, windmilling prop course and fine, stopped propcourse
andfine and stopped prop feathered. By using GPS and variometer and
altimeter readings we can fool with some different airspeeds into and with
the wind.Once numbers are ground willhave a better
understanding of best thing to do. Of course with oil still warm we can
practice air restarts.
Ron Parigoris
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