when to run up and check the prop

Ok, brother flyers, cards on the table here. I always do a run-up
before taking the active (my Mooney only sees pavement, so gravel
damage isn't a serious consideration) as do I think most of you. I'm a
M20J jock. I have, in some 3000 hours, returned to base after taxing
out only about 4 times. Once, in a normally inducted Mooney Ranger the
carb heat wire broke during that test (quite a surprise when you pull
out a foot of wire!), a couple of time because a radio wasn't working,
once because a bank of spark plugs weren't firing. Never had to come
back because the prop didn't cycle correctly.

I am NOT saying don't cycle the prop! I am wondering what failure modes
you guys have experienced during run up.

I've had in flight mag bank failures, vacuum pump failures, alternator,
radio, and common sense failures too. All but the last lead to a
landing at the nearest suitable airport (ever notice how often a
failure is in solid IFR?). The common sense failure modes did not
result in landing at the nearest airport or turning around, but they
should have.

OK, I've shown you mine. Let's see yours.

"Tony" wrote in message oups.com...
Ok, brother flyers, cards on the table here. I always do a run-up
before taking the active (my Mooney only sees pavement, so gravel
damage isn't a serious consideration) as do I think most of you. I'm a
M20J jock. I have, in some 3000 hours, returned to base after taxing
out only about 4 times. Once, in a normally inducted Mooney Ranger the
carb heat wire broke during that test (quite a surprise when you pull
out a foot of wire!), a couple of time because a radio wasn't working,
once because a bank of spark plugs weren't firing. Never had to come
back because the prop didn't cycle correctly.

I am NOT saying don't cycle the prop! I am wondering what failure modes
you guys have experienced during run up.

I've had in flight mag bank failures, vacuum pump failures, alternator,
radio, and common sense failures too. All but the last lead to a
landing at the nearest suitable airport (ever notice how often a
failure is in solid IFR?). The common sense failure modes did not
result in landing at the nearest airport or turning around, but they
should have.

OK, I've shown you mine. Let's see yours.


The reason for cycling the prop is to pump the cold oil out and move in the warmed oil. If the oil stayed warm from the
previous flight then there is no valid reason to cycle it again.

The MAG check is valid before every takeoff following a restart. Any number of things could have happened during the
last flight that would be revealed with this simple check....

Blueskies wrote:

The MAG check is valid before every takeoff following a restart. Any number
of things could have happened during the
last flight that would be revealed with this simple check....

Like taxiing to the runway without properly leaning beforehand.

I always do a run-up and prop cycle as part of every pre-takeoff checklist.


--
Peter


















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"Blueskies" wrote in message
m...
The reason for cycling the prop is to pump the cold oil out and move in
the warmed oil.

That's the reason for cycling the prop several times (I usually do it three
during a "cold" run-up). Cycling it at least once is for verifying proper
operation, and is a valid reason no matter how many times you've done it
before (by the same logic you use to argue for doing a magneto check every
time).

Pete

"Peter Duniho" wrote in message ...
"Blueskies" wrote in message m...
The reason for cycling the prop is to pump the cold oil out and move in the warmed oil.

That's the reason for cycling the prop several times (I usually do it three during a "cold" run-up). Cycling it at
least once is for verifying proper operation, and is a valid reason no matter how many times you've done it before (by
the same logic you use to argue for doing a magneto check every time).

Pete


Initial application of power and watching the RPM stabilize is enough to ensure proper propeller governor operation...

"Blueskies" wrote in message
news
Initial application of power and watching the RPM stabilize is enough to
ensure proper propeller governor operation...

That's like saying jiggling the yoke is enough to ensure that the controls
are "free and correct".