when to run up and check the prop

"BTIZ" wrote in message
news:39Yee.11385$fI.8996@fed1read05...
same thing happens on floats and a water take off..

Hmmm...I don't do my runup during the takeoff, even on the water. It's
true, I have no brakes and so the runup involves getting the airplane
moving. But once the runup is completed, I reposition myself for takeoff.

I can see that there are situations when doing the runup during the takeoff
would be useful and beneficial, but a water takeoff in a seaplane doesn't
seem to me to be one of them. Why complicate the takeoff unnecessarily?
(In John's example, the complication is necessary, but not so for a water
takeoff)

Pete

"Friendly Skies" wrote in message
...
[...] Their
rationale is that doing it four or five times a day is unnecessarily hard
on
the engine and when its been flown in the last few hours there's no need
to
cycle the prop more.

They may say that as many times as they wish. Without proof, it's an empty
statement.

They argue if there's a new problem during the day
like a mag, its easy to detect upon first throttle up as you take off.
You
would hear and feel the engine roughness and see its not developing full
power.

That argument holds as much validity for the first flight of the day as for
the Nth. Why bother doing a runup at all then?

Pete

"Friendly Skies" wrote in message
...
I fly some high performance, complex singles like Saratogas, Lances,
C182RG,
C206, and the like. Typical flying days have multiple hops while seeing
customers. On one hand I know pilots who say that you should do a full
run
up and prop check before every take off, because the checklist says to.
On
the other hand, I know pilots, mostly owners of similar aircraft, who only
do a full runup and prop check on the first flight of the day. Their
rationale is that doing it four or five times a day is unnecessarily hard
on
the engine and when its been flown in the last few hours there's no need
to
cycle the prop more. They argue if there's a new problem during the day
like a mag, its easy to detect upon first throttle up as you take off.
You
would hear and feel the engine roughness and see its not developing full
power.

Are there any good arguments out there based in science and fact and not
old
wives tales to support only doing a run up and prop check on the first
flight of the day ? I'm talking about a situation where you're flying
multiple flights a day and the engine never completely cools off.



Why do they suspect that the engine/prop is more likely to fail overnight?
Why not check it on the last flight of the day? Frankly, its a stupid idea.
If they think that its too hard on their engine then they need a tougher
engine (On the Helio the mag and prop checks are done at about 15" of MP,
(not much stress)).Similiarly, if they can detect a failed mag on the
takeoff roll then why check it at all while stationary?

There are good reasons to omit a prop of mag check, gravel or ice come to
mind. The reasons are obvious.

There is also a lot of safety to be gained by doing tasks the same way in
the same order every time.

Mike
MU-2

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...

Are there any good arguments out there based in science and fact and not old
wives tales to support only doing a run up and prop check on the first
flight of the day ? I'm talking about a situation where you're flying
multiple flights a day and the engine never completely cools off.

Are there any good arguments out there based in science and fact and not old
wives tales to support only doing a run up and prop check on the first
flight of the day ?

Well I never was one for science - more toward the arts personally so I
can't base anything on science for you.

What I can tell you is that last year our club was flying young eagles
and they decided that to save time we would only runup for the first
flight. I refused and actually took a lot of criticism for my refusal.

2nd flight - I'm the only one to runup - no left mag.
Plane parked - later the mag was removed and was found to be totally
dead as it had managed to internally disintegrate itself.

Should I have done the runup? Everyone else said no.
I would have been carrying 9 year olds over lakes and mountains.

2 years ago - 3rd runup of the day - another no mag day - parked.

So my unscientific opinion is that I don't fly unless I pass a full and
thorough runup, and if that p*sses somebody off - that's ok.
Because all of my flying is over lakes and mountains - and I don't fly
floats! So I check - and check again. If the checks don't meet my
standards I stay on the ground.

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE




--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

So if a warm prop governor doesn't work, what can happen? It will
either control or it won't. The airplane should fly if it turns up
either way. Why do multiple still-warm runnups unless you are just
trying to make the neighbors mad? or blow crap at everyone else's
airplane at the pad? or maybe just to sweep the pad?

On a second flight I just look for a dead mag on the taxi out, assuming
no other concerns. I do check car heat control feel-only if it is
dry, but fully check function if there is reason to suspect carb icing.

One I've never hear others say - I check the belly for oil before every
flight.