Fe: Engine Trouble
The flight to Santa Fe
was relatively uneventful. We dodged a few thunderstorms, but it thinned
out as we got closer. The controller wouldn't let us go VFR until we
had the airfield in sight, and this proved to be more challenging than
expected. There's something about the terrain that makes it hard to
see until you're almost on top of it. We wound up visiting the tower
and talking with the controllers and one fellow said he had the same
problem even though he'd been flying the area for years.
We did eventually find
the field, and touched down uneventfully. It was shortly after touchdown
that we discovered we had a problem. The right engine on the Navajo
stopped dead. At first, Steve thought it was just because he had kept
it too rich and pulled the rpm back too much for the high altitude field.
A CFI friend has since commented that on powerful turbocharged aircraft
he never lets the rpms fall below about 1000.
We had noticed during
the flight that the tach was acting funny too. I thought maybe it was
an electrical tach and that it was likely an electrical problem that
had killed the engine.
After trying the hot start
procedure several times, we were unable to get the engine started. It
wouldn't even pop. Clearly, something bigger was at work here. Reluctantly,
we called a tug to drag us in. The Navajo will not taxi on one engine--it
just tries to turn on the asymmetrical thrust and goes in circles.
Do you see a coyote in this picture?
sitting in the doorway of the plane, waiting for the tug, it
was very quiet and peaceful. I suddenly realized we were not
alone. A coyote was standing next to the runway sign looking
us over. You could see it clear as a bell with the unaided eye,
but as you can see from the photo, I need to get a camera with
a bigger lens to take these kinds of pictures!
Here's the U2 spy plane grainy closeup view of Mr. Wile
E. Coyote, or is that one of Fidel Castro's nuclear missiles?
this technology we might really have seen what goes on at Area
51 without overflying their airspace. Not!
definitely want a longer lens. Yes, I have lens envy!
about a 7:1 optical zoom and a 4-5 megapixel camera we'd be
able to count the hairs on his shaggy little body. Trouble is,
I'll probably never see I coyote under these circumstances again.
It's a sad, sad situation, and it's gettin'
more and more absurd...
At least that's
what Elton John says. Our dead and lifeless beached whale of an
airplane is being towed in. Its good to see that this happens
to expensive airplanes. For awhile I thought it only happened
to my exotic cars. The feeling of embarassment and shame is approximately
the same, which I found strangely reassuring.
The tug brought us here, near the FBO.
We sat in here for
about an hour and a half, in the forlorn hope that if the engine
cooled down it might prove to just be a hot start issue. The people
at the FBO were very friendly and helpful. Their mechanic had
gone home, and would not return for 2 days--it was a weekend.
However, they did have a CFI who was also a mechanic. They called
and he agreed to come out and take a look at it.
Needless to say,
it wasn't simply a hot start problem. It cranked and cranked and
didn't fire at all. By this time it was getting dark and everyone
was tired. We agreed to meet Larry, our CFI/mechanic the next
morning to try some more things. The FBO was also going to try
to call their full-time mechanic to see if he would come in.
BTW, for non-pilots,
the golf cart with the chequered flags comes out to guide you
in from the runway. Since we had a tug, this service was not needed
for the Navajo. Ahem.
The next day we
showed up bright and early to meet Larry at 8 am. They fooled
around with it while I strolled around the airfield checking out
the various other planes. There was quite a lot to see, and I've
included pix later on of the good ones.
and Steve were unsuccessful in their efforts. At this point, Larry
indicated he was in over his head and we needed a real full-time
mechanic. Since Executive Aviation's mechanic was out and we didn't
feel like waiting, we called the competing FBO, Jet Center, and
they informed us their mechanic was in and could look at the Navajo
as soon as he finished buttoning up a Cessna 206 he just finished
Here it sits, waiting to be worked on...
turned out to be about a 2 hour wait before he could start to
look at the plane.
During all this
waiting, Steve had occasion to call everyone he knew who had any
possibility of knowing anything at all about a Navajo engine.
You have to remember, Steve is a telephone guy. If he is near
one, he has to be talking on it unless something really critical
is going on. Short of an alligator gnawing on one leg, there isn't
much that qualifies as critical either!
The consensus among
these sages of the Navajo was that there was a problem with the
"shower of sparks". I fancy myself knowing a thing or
two about internal combustion, but I had never even heard of such
a thing. It all sounded very fishy. Imagine my surprise when Zeke,
our new mechanic announced that investigating the shower of sparks
would be his first order of business.
I never did get
a clear explanation of what a "shower of sparks" is,
so I feel it is incumbant on me to explain here after having researched
the issue. Basically, it is one of two methods by which the timing
of the ignition spark is retarded at starting. Normal spark timing
is relatively advanced so that it is optimal for an engine running
at 1000 rpm or more. Because the pistons are moving rapidly relative
to flame propogation from the spark, this works well. However,
the speed is very slow at starting, and the spark occurs at the
wrong point. In fact, if you try to start this way, it can result
in kickbacks where the firing is so early that the engine tries
to run backwards.
There are two fixes.
First is to use an impulse coupling to change timing. Second,
is to use a sort of external spark generating system that is separate
from the magneto. It's called a "shower of sparks".
It's basically a vibrator, like a doorbell buzzer, that just throws
off a continuous high speed stream of sparks.
A little knowledge
is a dangerous thing, eh?
To make it more
interesting, and because we'd really weakened the battery with
excessive cranking, Zeke trundled in an APU (Auxilliary Power
Unit) and plugged that in. The APU is basically a good-sized diesel-generator
on wheels. It has a honking big cable and is the prefered way
to jump start everything from a Cessna 172 to a Boeing 747. It
looks very cool and makes a helluva racket chugging away. There's
also a faint smell of ozone to add to the overall effect.
looked like Mr Shower O' Sparks was healthy. This left just the
magneto itself as our likely problem.
Zeke is inspecting the shower of sparks. Its installed in
the nose because it is shared between the two engines.
The mighty APU is connected!
testing for bad timing, bad connections, and so forth, Zeke proclaimed
that the magneto looked bad and needed to be pulled.
Steve has just gotten word that there is a
at the ugly little spud I remarked that it sure didn't look like
it had been recently overhauled, even though Steve had the plane
in the shop for just that purpose before our departure. Zeke concurred,
and as he got it out he mentioned that the overhaul sticker was
not on the unit, and that it didn't appear to have many new parts.
When pressed, he indicated it had no new parts. Hmmm, that's interesting.
What did those overhaul guys do, anyway?
got on the phone to see what the records said. Turns out they
had only "repaired" the unit. Checking back, he noticed
that the same mag had undergone "repairs" four times
in the last 12 months! Why didn't the shop bozos tell him he needed
a new one? I'd have been pissed if I was Steve. In fact, I would've
been pissed after repair number 2 failed. Steve is more easygoing
than I am, however.
Here is the bad magneto...
isn't hard even for a layman to see that this mag has been rode
hard and put up wet. For what those bozos (gee, don't read their
name off the sticker!) charged Steve on the four prior repairs,
he could've had a brand new one installed from the get go. From
my perspective, they should have recommended that instead of just
taking his money and potentially leaving him at risk of a bad
well, live and learn.
actually traced the problem to a set of points that go to the
shower of sparks. For some reason, they had loosened and closed
in the shorted position, preventing any spark from being generated.
He allowed as how he could simply reset the gap and get us going
again, but that Steve really ought to think about getting another
magneto soon. We nodded sagely and waited while Zeke got that
mag back in and then taxiid out to the runup area to test his
work. Things seemed to be going reasonably well for awhile and
then he throttled back, the engine died again, and he couldn't
get it started, so it had to be towed back to the hangar.
It's dead, Jim. Notice the odd angle? Even
Zeke can't taxi on one engine!
is not the sort of thing that inspires confidence. Zeke assured
us he could make it work well enough to get us home, but that
the mag needed to be replaced soon. Steve thought about it and
decided to quit screwing around and just get Zeke to replace the
mag. Hooray! Bob feels much better knowing we won't have to use
grandpa's mag that had been in continuous service since WWII to
fly home over the mountains!
Having made the
decision to wait for a new magneto, stress levels were reduced,
the schedule became less fluid, and we decided to take advantage
of the situation in order to see Santa Fe.
I'll finish this
lengthy tale before going on to describe what we saw in Santa
1 Echo Fox, dragged out of her warm lair with a new mag...
mag was overnighted (actually it was door to door the same day
with pickup at the airport, and Zeke installed it the next morning.
Here we are wheeling her out of the nice warm hangar to see
how well the new mag works.
ought to be feminine, they're certainly finicky and high maintenance
Prop not moving...
Those two pictures tell it all. We like it when the prop moves. We
love it when a plan comes together. After some more obligatory run-ups
things seemed much happier. There was less mag drop and the engine started
easier. We loaded the baggage while the mechanics put the engine covers
back on and then managed to roar off into the sunset by about noon.
Steve was muttering after take off that he wondered if there was any
way to justify flying the plane back to Zeke for maintenance since the
guys in the Bay Area were obviously inferior mechanics.
Thanks for all the help Zeke!
But don't miss out
on what we saw in Santa Fe itself...