Night flying in the mountians in a cessna 150,

Thomas Borchert wrote:
The odds will
catch up with you eventually.

You say we're ALL going to win the lottery?

Sure, if we play long enough.

Fly long enough, and an engine WILL fail. I've flown about 1900 hours
in powered aircraft, but 800 of those were in twins so I have about
2700 hours of engine time. I've had an engine failure caused by
mechanical problems. Once.

Michael

"Michael" wrote in message
oups.com...
Thomas Borchert wrote:
The odds will
catch up with you eventually.

You say we're ALL going to win the lottery?

Sure, if we play long enough.

That's not true. The longer you play, the more opportunities you have to
win. But each time you play, you have the same exact chance to win (all
else being equal, which means ignore the variations in chance due to
different numbers of participants, etc), and there is NO length of time you
can play that will guarantee a win.

Fly long enough, and an engine WILL fail.

Likewise, there is no length of time you can fly that will guarantee an
engine failure. Just as important: it doesn't matter how many hours you
have, the chance of an engine failure is exactly the same (all else being
equal) on each flight. Once you successfully complete a flight without an
engine failure, you can ignore that flight (and every single one prior) for
the purpose of assessing your risk on the next flight.

It seems that some pilots are going around thinking that the longer they
fly, the closer they get to their fated engine failure (or other problem).
That's just not true.

Mechanical problems do happen, and an engine failure can happen as a result.
An engine failure is a very real possibility, but it is also very unlikely.
But then, so is having your wing fall off. Or running into another
airplane, or a bird, or something. There are lots of risks associated with
flying, many of which the pilot has little or no control over. We accept
them because the actual likelihood is low.

IMHO, there is no clear cut "this is just plain too dangerous for anyone to
do", and that includes issues like flying over mountains, at night, IFR, in
a single engine airplane. It's entirely possible to have a flying career
comprising only IFR flights over mountains at night in single-engine
airplanes and still never have to deal with an engine failure, never mind
one over hostile terrain.

Besides, anyone arguing against doing that needs to expand the prohibited
class of aircraft to include any twin engine aircraft with a single-engine
service ceiling lower than the terrain (or MEA/MOCA/MRA) being overflown.

Pete

"Peter Duniho" wrote in message
...
"Michael" wrote in message
oups.com...

Besides, anyone arguing against doing that needs to expand the prohibited
class of aircraft to include any twin engine aircraft with a single-engine
service ceiling lower than the terrain (or MEA/MOCA/MRA) being overflown.

Pete

Having a single engine service ceiling higher than terrain is not really
that important. The single engine service ceiling is the altitude where the
airplane is still *climbing* 50fpm. The altitude where the airplane is
*descending* 50fpm is much higher. If you were cruising along at the MEA
and lost an engine, and the MEA was 5000' above the single engine service
ceiling, it would take tens or hundreds of miles to lose 2000' of altitude
and impact terrain. Actually you might never impact since the single engine
service ceiling rises as the plane burns off fuel. Barry Scheiff talks
about this topic in one of his books using actual numbers and the bottom
line is that you could lose an engine at the MEA in virtually any twin and
reach an airport, at least in the US.

Mike
MU-2

Mike Rapoport wrote:

If you were cruising along at the MEA
and lost an engine, and the MEA was 5000' above the single engine service
ceiling, it would take tens or hundreds of miles to lose 2000' of altitude
and impact terrain.

*If* there are no downdrafts. Remember, we're talking mountains.

Stefan

Downdrafts are always balanced by updrafts over any meaningful distance.. In
any event, if there were significant downdrafts, it wouldn't make much
difference if the plane could climb 50fpm or sink 50fpm in still air.

Mike
MU-2


"Stefan" wrote in message
...
Mike Rapoport wrote:

If you were cruising along at the MEA and lost an engine, and the MEA was
5000' above the single engine service ceiling, it would take tens or
hundreds of miles to lose 2000' of altitude and impact terrain.

*If* there are no downdrafts. Remember, we're talking mountains.

Stefan

Mike Rapoport wrote:

Downdrafts are always balanced by updrafts over any meaningful distance.. In

Make that "mostly". Mountains sometimes bear some surprizes, if you
don't know the region. Anyway, we were talking about night flying. Not
easy to find the right ridge ad night...

any event, if there were significant downdrafts, it wouldn't make much
difference if the plane could climb 50fpm or sink 50fpm in still air.

My point exactly.

Stefan

In article ,
"Peter Duniho" wrote:

Likewise, there is no length of time you can fly that will guarantee an
engine failure. Just as important: it doesn't matter how many hours you
have, the chance of an engine failure is exactly the same (all else being
equal) on each flight. Once you successfully complete a flight without an
engine failure, you can ignore that flight (and every single one prior) for
the purpose of assessing your risk on the next flight.

That's true, but the longer you fly (or play the lottery) the closer
your probability of experiencing an engine failure (or a lottery win)
some time your career approaches 1.

Of course, you might have to fly/play for a *very* long time before that
probability actually gets close to 1, but sooner or later it will be 1
to any desired degree of accuracy. So the statement "fly long enough and
you will experience an engine failure" is pretty close to being true.
The question is how long is "long enough."

rg

Peter,

That's not true. The longer you play, the more opportunities you have to
win. But each time you play, you have the same exact chance to win (all
else being equal, which means ignore the variations in chance due to
different numbers of participants, etc), and there is NO length of time you
can play that will guarantee a win.


Or, in other words I like a lot: There is no law of small numbers.

--
Thomas Borchert (EDDH)