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First Union Securities, Inc.
What a long week... and things never go as planned. Of course my plan
probably was not very realistic. I envisaged a half-day of preflight and
several days of flying. Yeah, right. So here is what really happened:
Friday afternoon I loaded the plane to take it to the airport - about 20
miles away. Not a fun project. We used a rollback wrecker and drug the
plane up the bed of the wrecker with the main gear resting on a support (I
call it the "outrigger") fashioned from a 2x10 and some 2x4's. Reasonably
smooth process - and what a site going down the road. Unloading was a lot
more difficult, as the plane wanted to roll off the back of the outrigger,
in spite of a 2x4 chock behind the wheels. But eventually it came off with
no damage - yeah! Now the really annoying part- putting the wings on at
7:00 PM in 30 degree breezy weather. Outside. The airport where I am
keeping the plane doesn't allow any maintenance inside the hangar. After
fumbling with nuts and bolts for about two hours I was done.
Saturday morning Charlie Kohler arrived to provide the DAR inspection and
the required paperwork. Done without a hitch (except Charlie's return
flight was cancelled). Thanks Charlie.
Sunday morning. Mike DeHate arrived. Mike had already spent some time with
me and the plane in late June, so he was familiar with the plane, the
engine, and the panel. We spent Sunday afternoon looking over the plane and
for the most part it was good. We identified a few items to fix and went
home for the night.
Monday morning. Changed the camber on the right and left gear and got the
gear doors realigned. All seems to work fine. Also broke my pitch trim -
fortunately I had a spare MAC 6A servo at home. But I broke a pin trying to
change the connector, and spent a few hours trying to find a couple of those
tiny pins. Accomplished. It's very cold (for NC) and we drag the plane out
to run it. It wouldn't start. We were getting voltage to the starter, so
we were about to pack it up and order a new starter when Mike found a loose
connection on the starter. Bingo. Prop turned over very weakly (dead
batteries from months of non-use). But it started. And it ran darn well,
at least on one of the computer systems. The plane has an IO360 that has
been converted to dual electronic ignition and dual electronic fuel
injection. The "A" system ran beautifully, but the engine choked, gasped
and blew black smoke on the "B" system, except at high RPM, then it ran
great too. Couldn't figure it out. So we went home.
Tuesday morning we went back to the airport, with computer in hand. Plugged
into the engine computer system to monitor the engine parameters. The
problem jumped right out - a defective Manifold Air Pressure sensor (MAP).
The MAP on the "B" system read way too high, and was causing the computer to
dump gobs of fuel into the engine at low power settings. Resulting in a way
too rich setting and a sick engine. We swapped the MAPS between "A" and "B"
and the problem followed the MAP. Unfortunately, my day job was calling, so
I had to leave at 11:00 AM to go to New York. Mike was a huge help and ran
around looking for a GM dealer to buy a new MAP sensor. Darus Zehrbach also
fedexed a new one down in case we couldn't find one at the dealer. Mike
found one and installed it Tuesday evening.
Wednesday - I took the brutal 6:30 AM flight back from NYC and went straight
to pick up Mike and go to the airport. I changed out of my suit and into
jeans on the tarmac in 30 degree weather. COLD again. But Mike had put the
chargers on the batteries, and we drug the plane out of the hangar to start
it. Bingo. Plane started right up, idled beautifully. I was sitting in
the passenger seat with the computer in my lap monitoring both engine
computers (they both can be run at the same time, but only one controls the
injectors at any given time). Both were reading the same manifold pressure.
YEAH! Mike switched back and forth between the two computers a few times,
and nary a hickup. The engine seems fine. Mike did a few high power tests,
and then ran it up and down the runway a few times. All seemed fine. So he
came back and we checked everything out again. He then went back to the
runway. A few highspeed runs down the runway, and he radioed that he was
going to line it up for a flight. He had to wait about 5 minutes for
traffic to clear, then he taxied to position. He screwed the throttle...
and radioed that he was aborting - the engine was "surging". So he came
back in and we stared at the engine for a while. We let it cool down and
tried to get the problem to repeat itself. No luck (but we did get some in
the cabin as some residual oil trapped in the heat muff burned off (source
was a broken oil line - reported in LNN a few months ago). So we pushed it
in the hangar and called it a day. We called Darus Zehrbach and discussed
the problem with him. No one had any great ideas - the only thing we could
come up with was a fuel starvation - maybe from the Vision Micro fuel flow
sensor (it has a restrictor in it).
Thursday morning we removed the VM flow meter and reconnected a straight
hose. Checked and cleaned the gascolator. Took the plane back out and ran
it pretty hard. All seemed to be fine. Time for turkey/. Off to
grandmothers to eat a wonderful turkey cooked by my girlfriend. And I don't
even like turkey. After lunch we went back to the airport. Mike made a few
high speed runs, and everything still seemed good. So he took off. I was
holding my breath and nervous as hell. Mike climbed in the pattern and
everything looked fine from a distance (no wings falling off...).
Then he radioed that he was coming back in. That was part of the plan.
Long story short, the prop oversped. Pretty severely. As soon as Mike put
the gear up, he said the prop started speeding up. He pulled the prop
control all the way back, and then pulled the power too. But he couldn't
keep the RPM down. So he landed (a beautiful landing too).
So my plane is now a plane, but it is also still a project. We pulled the
prop governor, and I will be trying to identify it that is the problem. It
is a newly overhauled McCauley unit, and I have an MT-12B propeller.
Hopefully the issue is the governor. It is easy to fix, and can be shipped
easily. We'll see. We think the problem with the engine surging on
Wednesday probably was the prop overspeeding too. This appears to happen
only when the oil temps are very high (around 250 degrees).
Mike left this morning, a day early. I guess the airplane won't see the air
again for a while. What a bummer.
Matt
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Please send your photos and drawings to marvkaye@olsusa.com.
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