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Paul, as they say - a good landing is if you
wall away from it - an excellent landing is when the aircraft will fly again
without repair and an Outstanding landing is all of the above but, you don't
leave skid marks on the taxiway. Certainly glad everything ended as well
as it did - good thinking and decision making under a bundle of stress - I know,
I have left skid marks for 300ft after aborting a take off, ended up 12 ft
off in the grass.
Here is a wild guess at what could have caused
your problem. I would wager that you did not reprogram the map after
putting on the smaller dia prop. My aborted take off occurred because I
had been tuning the ECU (not Tracy's EC2 - an aftermarket auto unit) with a
Laptop - but, of course I could not tune the map for those rpms above static
until I got airborne. So on the ground, I extrapolated for the
higher rpms figuring to refine them in the air. As soon as I lifted off
and had gained approx 20-30 ft of altitude, the engine revved into the part of
the rpm range that I had extrapolated the Map settings. The engine
immediately dropped from 5000+ rpm to around 3500 rpm, recovered and surged back
to 5000 then died back down to 3500. Despite being airport and 80MPH I
elected to abort on this 2200 ft runway. Touched down firmly 300ft from
the end (measure the tire tracks) got on the binders very hard (you know what I
mean - glad I had the nose wheel) and left rubber (actually no skids - no flat
spots of tires) just rubber digging into the tarmac from point of touch down to
rolling off the grass. I remember dodging between two end of runway light
markers so I wouldn't ding my flaps. Funny what you think of at times like
that..Now, in my case if I had just had the time to reach over an play with the
mixture control I might have found that full rich would have enabled flight - or
if I had taken one more fraction of a second in making a decision I truly could
have been in bottom of a ravine at the end of the runway.
But, the point of my tale is I suspect that one
possible cause might be your engine getting into a higher rpm region of your
fuel map which you perhaps couldn't get to with the larger prop. If so?
(and a big IF I admit), then if it were too lean the engine would lose
power. In any case, a hearty pat on the back for handling a very
challenging situation with cool aplomb (well, hell nobody was with you to say
otherwise {:>)
Best Regards
Ed
----- Original Message -----
Sent: Monday, February 07, 2005 9:09
PM
Subject: [FlyRotary] Bad day at the
airport
On Sunday I decided to do a little "tweaking" on
the ECU fuel mixtures on my 13b powered SQ2000. I had the larger 3
bladed Performance prop on, and just wasn't getting the rpm's I wanted, so I
put the smaller dia/less pitch prop on and took it to the end of the runway
and once I was lined up on the runway, advanced the throttle to wide open.
RPM's were only around 5100, but I have flown it that way before, so I decided
to go ahead and try to work with the mixture programming at 5000 feet.
Acceleration was normal, liftoff in less than 2000 feet, and started my climb.
At approximately 250 feet, the engine started failing rapidly. I tried various
throttle positions, with no improvement. Unable to maintain altitude. I
immediately started a left turn, hoping maybe the engine would recover enough
to just get me to 500 feet downwind so I would have a chance of making the
runway. No such luck. I was now heading back toward the center of the
airport at approximately 100 feet and descending. I wanted to land on
the center turn-off section in the middle of the airport, but that would have
me landing straight towards several parked aircraft and the main hangar.
Not the best option. There is a newly paved area slightly to my left,
where aircraft may be tied down in the future, but it was empty for now. I was
out of options and altitude. I crossed the runway at less than 50 feet. I
didn't want to land going across the runway, because the grass and mud I would
encounter after rolling across the runway would probably flip the aircraft
over. I headed for the new aircraft tie-down area, and attacked it at a
45 degree angle to get as much "runway" as possible. I held it off
until I was over the parallel taxiway, and landed on the parallel taxiway (the
short way, of course) and with heavy braking, began skidding across the
aircraft tie-down area. (See attached photos). I knew I couldn't stop in
that short a distance, but hopefully when I went off the other end of the
pavement, I would not be going as fast. The nose was dipped down at an
angle from all the heavy braking, so I had a nice view of what was coming.
Grass, mud and a ditch. The aircraft kept slowing down, and as I ran out
of pavement, I wasn't going all that fast. I probably only went 10 feet past
the end of the paved area into the grass and came to a stop. Missed the
ditch by almost 5 feet !!! No problem...that was fun !!! Just don't care
to do it again. I restarted the engine and taxiied back to the hangar,
pretending nothing had happened. I don't know what to do at this point.
I don't care to have this much fun again anytime soon. I'm torn between
a carburetor and a Cessna. Paul Conner
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