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Hi Ed & all. I just posted an overview. Not that any of this was the fault of the engine type, but here are a few of the details in case they help other rotary enthusiasts with fuel system design.
During the leg from SFQ to BNL I noticed occasional reduced fuel pressure / increased EGT on right tank that was corrected by engaging left pump. Suspect the beginning of filter clogging. I should have done something about this at BNL but didn't. The airplane was talking to me.
I now suspect that the high volume / high pressure gas pumps at SFQ and BNL swirled the fuel in the tanks and brought up crud that wasn't disturbed by my normal fill from 5 gal cans. Something to watch for, new composite fliers....Chris, especially.
Immediately I switched on the right pump (over JAX area) the engine spluttered and apparent rpm reduced from 5400 to around 3400. Turning off right pump made no difference. EM2 readings showed rpm at 6400 and 6900 which seemed double, and EGT went from 1550 to 1800+. Obviously I throttled back. The engine ran in this mode until touch down (sorry ED - you can keep your damned trophy :) Thinking back, it could have been running on one rotor.
On final I was coaxing as much power out of her as I could get. (I was in a squall and was experiencing very high turbulence / wind sheer, but that's a whole other story). The best she could do downhill on full throttle was about 130 kts. After touchdown the engine cleared up and ran normally until shut down.
Just ignore the failure to restart problems - it had been a long day and I was working, shall we say, under duress, to get the plane the hell away from JT's from gate :) Once the fuel valves were switched on (duhhh) the engine started and ran normally on the final leg.
Regarding the oil (duhhh # 2). Yes - I added oil at 17FL. I suspect there was still some in dilution in the tanks. There was about 10 gals in each side when I added 14 gals more / side at SFQ, and the same at BNL, so maybe I still had 1/2 oz / gal.
>Were your fuel pumps running without fuel when the shutoff
Yes - the right one is dead now. Left one seems fine. Right one was an E2000 model originally from Tracy. The left one is a GSL393. I think I'll get another GSL393 - they're quieter too.
>I would be very careful over the next few hours to religiously check the filters frequently to
>ensure no further collection of junk.
Absolutely, but note that they WERE clean until I 'injected' gas into the tanks at high speed, then one of them got dirty real quick - interesting.
>gets your heart rate up a bit doesn’t it?
Actually I was more "winded" than shaken. More later....
>What was the first symptom?
Not counting the high egt on right pump earlier, rough running on switching on right pump (left pump was still on).
>What caused you to realize it was an urgent problem?
huh? rmp goes from 5400 to 3500 and engine feels very rough. Nothing I do seems to improve things ??? That counts as urgent to me, especially when I happen to be overhead a squall line.
>How long did you mess with the problem before turning toward an airport?
about 10 seconds, then more during the decent, then it got kinda busy below 3000'
>What did you try to isolate/identify the problem or was it obviously a fuel problem (I have had both fuel and >electrical problem and thought both were fuel problems)
The effect was instant on turning on right pump - that basically targeted me on fuel starvation. What I couldn't figure was that turning off the pump (and leaving left pump on) made no difference. I didn't consider other causes.
>What finally made you decide you had to land?
At full throttle I was barely able to maintain altitude on the few occasions I wanted to (like tracking back under the cloud base to get to 17FL). rpm doubling worried me, and the engine felt like crap - the more I think of it the more I think it was on one rotor, which fits somewhat with the rpm doubling indication. I have a natural tendency to put my wheels on the ground immediately if things don't seem right. I had a VERY helpful flight following controller from Jax center, told him I had engine problems, then basically just followed his vectors. Lesson learned. Always use flight following - those guys are superb in an emergency, and they help you around weather / restricted space / MOAs etc as part of the job.
>What type of approach did you make?
RBC. (rapid and barely controlled). I was bouncing 50 feet up and down and correcting 40 degree banks on 1/4 mile final!
>And did you still have power during landing
yes. 3500 rpm full throttle. I believe I touched down at about 135kts.
I'll do a pirep on the emergency landing (separate to the cause) in a little while.
Any theories on the rpm doubling (I'm certain of the 6900 rpm reading).
How could switching on a pump cause that? Could I have been running on one rotor???
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