SEL precautionary landings: what's your experience?

I have landed because of mechanical failures maybe once every 300
hours. I had a vacuum pump fail (VMC, I'm happy to say), an alternator
(In the clouds but soft IMC), a magnito failure that took out a bank of
spark plugs (probably IFR, I don't remember for sure) -- things like
that. Nothing really awful, but every one caused me to land a couple of
hours short of my destination. Most of these happend in my own M20J
which was (at least I think it was) well maintained.

What about those of you with 500 plus hours: what has your experience
been like? Am I just unlucky, or typical?

I've only had 4 or 5 mechanicals in 2800 hours. Being VFR only, there
have been more more instances of not making it to my destination
because of weather.
--
Gene Seibel
Hangar 131 - http://pad39a.com/gene/plane.html
Because I fly, I envy no one.

What about those of you with 500 plus hours: what has your experience
been like? Am I just unlucky, or typical?

In my 1300+ hours, I have only encountered two situations, both were
decisions to not take off.
The first was a 182Q with the oil pressure gauge needle pegged full
right following startup.
The second was a Turbo Arrow IV with a bad mag found during runup.

On a short cross-country in a C-150 I pulled the cabin heat on and loaded
the cockpit with gasoline fumes. I immediately closed the heater vent but
the fumes didn't go away. Leaving a window opened at least brought in some
fresh air. Made a precautionary landing about half-way to my destination.
When I did the GUMP list I felt the carpet soaked with fuel. Turns out the
fuel shut-off valve packing was dribbling gasoline into the cabin. When I
opened the cabin heat vent, the air movement stirred up the fumes that were
collecting below my knees.

By the way, just to stir up a previous thread -- when I declared my
intentions to make a precautionary landing (without declaring an emergency)
the tower rolled the equipment. The only flak I caught was from the fire
chief for taxiing the airplane off the runway to the apron. In hindsight, I
probably should have stopped and ran -- like he said.

I didn't actually land, but one time at the beginning of a long 6 hour
trek back home in a 172SP I did encounter an engine sputter. It was
really just a momentary dip in RPM, but out of the ordinary enough for
me to worry. I was climbing through maybe 2000 feet AGL when it
happened, so I decided just for safety sake to continue the climb, but
turned around direct back to the field. Checked the mixture, fuel
selector, nothing seemed out of the ordinary, and RPMs didn't fluctuate
at all again, so decided to return back to original enroute course.
Trip ended without it happening again.

--
Guy

"Tony" wrote:

I have landed because of mechanical failures maybe once every 300
hours. I had a vacuum pump fail (VMC, I'm happy to say), an alternator
(In the clouds but soft IMC), a magnito failure that took out a bank of
spark plugs (probably IFR, I don't remember for sure) -- things like
that. Nothing really awful, but every one caused me to land a couple of
hours short of my destination. Most of these happend in my own M20J
which was (at least I think it was) well maintained.

What about those of you with 500 plus hours: what has your experience
been like? Am I just unlucky, or typical?

Twice in 1100 hours: one failed voltage regulator in IMC, one engine
vibration in VMC (prop put on wrong way round during annual).

--
Dan
C172RG at BFM

You landed short of your destination because a vac pump failed in VMC??

-Robert

Got 20 min away from the airport, heard something knocking, turned
around and went home. Decided that if I had to land someplace other
than the airport, I'd rather be going towards the airport and
following the interstate rather than continuing on, when I knew that
my airport was considerably closer than the next one towards my
destination. Mag cover had come loose and was rattling.

Coming home from NM to Denver (night) following I-25. All of a sudden
I couldn't see the lights of Denver (just south of COS with clear
vis). Called COS and requested vectors, landed, borrowed the crew car
and drove home (about an hour). Came back the next morning, dropped
the crew car and flew home.

Finished runup, got cleared for takeoff. Rolling down the runway,
called the tower and stated I was cancelling takeoff. (You can do
that real easy at an airport that doesn't have lots of traffic.)
Serious shimmy on nose wheel, so much so that I felt that there
would be a possible danger when landing later on.

There have been numerous occasions when I decided I didn't like the
weather, despite DUATS and FSS. About 90% of the time, I'm right. The
other 10%? So what? 9-1 odds are really good!

"Tony" wrote in message
oups.com...
[...]
What about those of you with 500 plus hours: what has your experience
been like? Am I just unlucky, or typical?

Probably similar. Like Robert, I wonder why you felt it necessary to make a
precautionary landing when your vacuum pump failed in VMC. Were you flying
under IFR? I was VFR the one vacuum pump failure I experienced, and I not
only completed that flight, but made another one to take the airplane to the
shop to have it repaired ("placarded" inop).

As far as other mechanical problems/precautionary landings go...

I did have a magneto failure. I didn't find out until my next flight. The
only symptom was slightly higher fuel flow for the same power setting. So,
no precautionary landing there, but there would have been had I any idea
what was actually going on.

My most dramatic (as in nerve-wracking) precautionary landing happened right
after a takeoff. During my first turn in the pattern, I felt/heard an
unusual noise combined with a slight drop in power. I immediately told the
tower I needed to land and, while keeping an eye on the runway, nervously
made my way around the pattern.

Everything turned out okay, but it took awhile to figure out what was
actually going on. In fact, it turned out to be two completely unrelated
problems. The first, more serious, was a p-lead that was wearing against a
corner, cutting through the insulation and shorting it out. That didn't get
diagnosed for a few months, until it had worn enough to actually show up
during the run-up.

The other problem, that was actually causing the unusual noise I had
noticed, only recently got resolved. After a few years of complaining about
it, and having the airplane inspected thoroughly numerous times in search of
any problems, my mechanics finally discovered two engine mounts that had
been installed backwards. That had misaligned the engine just enough that,
under just the right conditions, some additional engine vibration made it
through the airframe, causing the noise I was feeling and hearing.

I don't know whether those two problems really count as two events, since
they only resulted in the one landing. I'm not even sure that either one on
its own would have scared me enough to get me to land; for sure, the
combination got my instant attention.

There have been other mechanical issues that, thankfully, were caught during
inspections of the airplane (mostly preflights) and which could have easily
turned into unplanned landings. All told, I'd say that 300 hours per might
be a *little* on the high side for *landings*, but it's a pretty good track
record if you're counting ALL mechanical issues that might have forced a
landing, whether you did make an early one or not. In either case, I doubt
it's far from the average. You'd have to have a lot more mechanical
problems than that to warrant being called "unlucky".

Pete

That is what the regs call for!


"Robert M. Gary" wrote in message
oups.com...
| You landed short of your destination because a vac pump
failed in VMC??
|
| -Robert
|