Sorry I didn't make to Bill Eslick's for the Rotorfest, I missed by
about one hour. About 30 miles north of San Angelo TX the RPM suddenly
dropped and I could not restore it with any of my emergency
procedures. GPS told me nearest airport was Robert Lee about 15 miles
away. I headed there and landed without incident.
Turning the prop by hand shows almost zero compression in one rotor,
indicating bad/broken apex seals, quite similar to my engine-out
experience 2 1/2 years ago which caused a forced landing near the
Grand Canyon. This time the vibration was not quite as bad, and the
RPM dropped to around 4300 which was still not enough to maintain
altitude. I called my friend with a Glasair and he cam got me and took
me home. I will have to find some time to build another motor and
drive 12 hours back there and swap motors. Or I might drive there,
remove the wings and trailer it back, have not decided yet. My good
friend/mentor/flight instructor is trying to talk me into going back
to a Lycosaurus, and I have to think of some good reasons not to.
Until I get the motor back and torn apart, I wont know what caused the
failure, but I will post anything that I find.
Regards
Chuck Dunlap
RV-6 13B 535 hours
Glad everything worked out well Chuck.
I'm surprised you can't maintain altitude with 4300 RPM. Must be
differences in airframe and propeller pitch. I can maintain altitude at
70 to 80 knots with around 4000 RPM. At 3800 RPM I come down really
slow, like 100-200 fpm. I do that for fun when I'm out goofing off, kind
of like flying a glider. Those numbers were about the same when I had
the ducted fan. I have not run an air filter in my 560 hours of flying,
no problems. Any FOD entering my ram air inlet under the right strake
has to go through the airflow sensor and then uphill about 1 foot to get
into the engine intake. It will be interesting to see what you find.
Perry
Thanks, Perry. What is your cruise RPM? I run 6000 to 6200 at cruise and
around 5700 at takeoff. Performance Prop 67" dia, unsure of pitch, I
think 68 or 70". Probably only making about 50 HP on one rotor, the
vibration from unbalance seems to soak up a lot of HP. I was descending
about 100-200 FPM at 4300
Chuck
5700 at the start of the take off run Chuck? Static RPM?
Paul Lamar ...No rotor no motor.
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