> >>>>>Chuck wrote:
>>>>>
>>>>>Well I did not make it to Arlington. I was over the Grand Canyon at
>>>>>12000 ft when the engine suddenly started shaking and RPM dropped to
>>>>>
>>>>>
>>>>>3900. Turn on the aux fuel pump, tried backup engine controller,
>>>>>tried disabling trailing then leading ignition, everything looked
>>>>>normal but RPM. GPS reported nearest airport was Marble Canyon 21
>>>>>miles away. Set up best glide, headed for Marble Canyon, looked at
>>>>>EGT and rotor #1 (rear rotor in RV6, front rotor in car) was showing
>>>>>
>>>>>
>>>>><400F. 12 minutes later, Marble Canyon was 1 1/2 miles out but could
>>>>>
>>>>>
>>>>>not reach it so I set up approach on Highway 89A. It was looking
>>>>>good until a truck pulling a travel trailer appeared from around a
>>>>>curve, heading right for my intended touchdown spot. He made no
>>>>>attemp to pull over, so I had to stay above him. After he passed, I
>>>>>tried to set it down but did not have enough speed to flare so it
>>>>>dropped in pretty hard. Got it slowed down and off the road, luckily
>>>>>
>>>>>
>>>>>there was a nice wide spot waiting for me. I got out and surveyed
>>>>>the situation, the port wing had struck a highway marker post just
>>>>>inboard of the wingtip and ripped a 2 foot gash in the lower wing
>>>>>surface. The main and tail spring gear were all slightly bent from
>>>>>the impact. Later after the engine and I had cooled off, I pulled
>>>>>the plugs one rotor at a time, and sure enough there is no
>>>>>compression on rotor #1. My friend flew up and picked me up, we flew
>>>>>
>>>>>
>>>>>home, loaded up tools and trailer and made the 8 hour drive up
>>>>>there, removed the wings loaded it up and headed back to Safford.
>>>>>It has been an interesting couple of days. It will take a bit longer
>>>>>
>>>>>
>>>>>than that to repair the damage. I will report on the engine when I
>>>>>get it apart.
>>>>>
>>>>>Chuck Dunlap
>>>>>
>>>>>
>>>>Real sorry to hear that Chuck.
>>>>
>>>>Thank heaven you made it OK. Congratulations on a saved-my-ass-job
>>>>well done. Also good job on the design of the motor mount as the
>>>>engine would have dropped out on the road if it had been weak.
>>>>
>>>>Were those three piece apex seals?
>>>>
>>>>For the new people. This is the very first failure of the basic
>>>>engine that I have heard about in the five year history of the news
>>>>letter. Apex seal failure is common on turbo engines that are subject
>>>>
>>>>
>>>>to detonation. Apex seal failure is rare on normally aspirated
>>>>engines like Chuck's but has been experienced in car engines with the
>>>>
>>>>
>>>>three piece design. They are less tolerant of high wear. The new RX8
>>>>motor has gone back to the two piece design.
>>>>
>>>>Paul Lamar
>>>>
>>>>
>>>Hey Chuck,
>>>I was looking for you at Arlington, since you were supposed to arrive
>>>there before me. Really glad to hear there were no injuries. Can you
>>>clarify something: did you have partial power at 3900 RPM on the way
>>>down, extending your glide? If not, what were then conditions when the
>>>
>>>
>>>engine quit running?
>>>
>>>That sounds similar to an apex seal failure I had in a 1987 turbo car.
>>>
>>>
>>>In that case it was the rear rotor. Suddenly the car lost power big
>>>time. I could keep the engine running by keeping my foot on the gas
>>>pedal. Managed to clutch and brake and keep the right foot on the gas
>>>pedal for 30 miles to get me home, through stop lights and everything.
>>>
>>>
>>>Once home and I turned off the engine, it would not start again, as I
>>>suspected it would not.
>>>
>>>--
>>>Perry Mick
>>>
>>>
>>Perry, sorry to miss you @ Arlington. The engine was running enough to
>>extend the glide a bit. I had about 8000 ft AGL and I went about 21
>>miles. I believe the glide ratio of the RV's is 10:1, if that is correct
> >>I should have had a 15 mile glide with no power. It takes about 4100 RPM
>>to maintain altitude in my ride.
>>I have not yet tried to restart the engine, it kept running until I
>>pulled off the highway and shut off fuel, that was all I needed.
>>
>>Chuck
Chuck,
Thanks for clarifying that. So it did continue to run, that is good
news. I think mine will barely stay level at 3800 RPM and 80 knots. But
if I lost one rotor who knows if it would even make 3800?
--
Perry Mick
Custom Composite Props
mick@bridgingworlds.com
http://www.ductedfan.com
Another plus for a nitrous system, it could have made difference on
getting over that truck and making a good flair.
It would have given an extra 40 hp for 1.5 minutes.
Ken Welter
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2003 All world wide rights reserved.