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Thanks for your report, John - even though it looks like I am forced to
retain that damn trophy (for now {:>)).
Right decisions - obviously. Certainly sounds like the high pressure fuel
might have stirred up crap that got into the filters. I guess that raises
the question about whether the composite tanks need some better method of
ensuring all the crap is out (other than this way {:>)) after work is done
on them.
Clearly most folks don't have access to high pressure fuel pumps - high
pressure air might do the job, but I assume that was used. Could be fiber
that was just barely attached and that was knocked loose by the fuel greater
mass and the pressure.
Always gets my heart to pumping a bit harder when such things occur to me.
I also notice how time seems to expand in one sense. I didn't realize how
much until I did calculation about how much time I had to turn base after
passing the upwind end of the runway - less than 30 seconds for a 5000 foot
runway. Yet, it seemed I was on downwind for several minutes {:>)
Very glad to get the report
Best Regards
Ed.
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of John Slade
Sent: Thursday, September 03, 2009 11:17 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Report JOHN!!!! : [FlyRotary] Help for John Slade
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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