when to run up and check the prop

[Friendly Skies]

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.

[Bob Chilcoat]

I'd only run up and check the prop when the engine's not running. You can
get hurt otherwise :-)

--
Bob (Chief Pilot, White Knuckle Airways)

[A.Coleman]

> 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 ?

How about lowering the risk of an engine failure in the air by inducing any
impending failures while on the ground?

[houstondan]

Bob Chilcoat wrote:
> I'd only run up and check the prop when the engine's not running.
You can
> get hurt otherwise :-)
>
> --
> Bob (Chief Pilot, White Knuckle Airways)

sissy

\
dan

[John Galban]

Friendly Skies wrote:
<snip>
> 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.

I don't see why a runup or a short prop cycle should be unnecessarily
hard on the engine. If they're stopping that many times a day, they'll
get the procedure down to a few seconds.

In the backcountry, where there is often no place to runup without
sucking rocks into the prop, we often do the mag check early in the
takeoff roll. It's an extra step during a critical phase, but I
always feel more comfortable rolling towards the trees and rocks at the
end of the runway when I know all of the plugs are firing on time.

John Galban=====>N4BQ (PA28-180)

[Charles O'Rourke]

Bob Chilcoat wrote:
> I'd only run up and check the prop when the engine's not running.
You can
> get hurt otherwise :-)

For some corny reason, this made me burst out laughing at work. How
embarassing.

Charles.
-N8385U

[Peter Duniho]

"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

[Mike Rapoport]

"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

[Tony]

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.

[George Patterson]

Bob Chilcoat wrote:
> I'd only run up and check the prop when the engine's not running. You can
> get hurt otherwise :-)

Booooooo!!!!!

George Patterson
There's plenty of room for all of God's creatures. Right next to the
mashed potatoes.

[Matt Barrow]

"John Galban" > wrote in message
oups.com...
>
> Friendly Skies wrote:
> <snip>
> > 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.
>
> I don't see why a runup or a short prop cycle should be unnecessarily
> hard on the engine. If they're stopping that many times a day, they'll
> get the procedure down to a few seconds.
>
> In the backcountry, where there is often no place to runup without
> sucking rocks into the prop, we often do the mag check early in the
> takeoff roll. It's an extra step during a critical phase, but I
> always feel more comfortable rolling towards the trees and rocks at the
> end of the runway when I know all of the plugs are firing on time.
>

Not exactly a match, but http://www.avweb.com/news/columns/182082-1.html
offers some good, helpful basics that might answer some peripheral
questions.

[BTIZ]

same thing happens on floats and a water take off..

"John Galban" > wrote in message
oups.com...
>
> Friendly Skies wrote:
> <snip>
>> 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.
>
> I don't see why a runup or a short prop cycle should be unnecessarily
> hard on the engine. If they're stopping that many times a day, they'll
> get the procedure down to a few seconds.
>
> In the backcountry, where there is often no place to runup without
> sucking rocks into the prop, we often do the mag check early in the
> takeoff roll. It's an extra step during a critical phase, but I
> always feel more comfortable rolling towards the trees and rocks at the
> end of the runway when I know all of the plugs are firing on time.
>
> John Galban=====>N4BQ (PA28-180)
>

[Peter Duniho]

"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

[tony roberts]

> 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

[Joe Johnson]

"Bob Chilcoat" > wrote in message
...
> I'd only run up and check the prop when the engine's not running. You can
> get hurt otherwise :-)
>
> --
> Bob (Chief Pilot, White Knuckle Airways)
>
C'mon, Bob...we're trying to be serious here...

[Blueskies]

"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....

[nrp]

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.

[Peter R.]

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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[Peter R.]

tony roberts > wrote:

> 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.

Hopefully your two past experiences were enough to silence the nay-sayers
of your club and change their mind (for their own good and the good of
their passengers). Good for you in sticking to your training and instinct,
despite what appeared to be overwhelming peer pressure.



--
Peter


















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[Peter Duniho]

"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]

"nrp" > wrote in message
ups.com...
> So if a warm prop governor doesn't work, what can happen? It will
> either control or it won't.

Or the failure could be causing oil to be pumped overboard. The only
initial sign from within the cockpit could be the lack of governing, but
you'd still want to get the plane back to the shop ASAP, *without* flying it
first.

> [...] 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?

At every airport I've ever been, there is a suitable run-up area away from
"everyone else's airplane" and from "the pad" (whatever THAT is). Neighbors
have no idea whether it's your first run-up or your tenth, and it'd be a
pretty odd situation indeed for your individual operation to make the
difference between a neighbor being mad or not. Generally, any neighbor who
can actually hear a run-up is either very pro-aviation, or they've already
been trying to close the airport for years.

Pete

[Blueskies]

"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...

[Peter Duniho]

"Blueskies" > wrote in message
m...
> 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".

[nrp]

Peter Duniho wrote:
> "nrp" > wrote in message
> ups.com...
> > So if a warm prop governor doesn't work, what can happen? It will
> > either control or it won't.
>
> Or the failure could be causing oil to be pumped overboard.

Do you get out and look afterwards to see?

Generally, any neighbor who
> can actually hear a run-up is either very pro-aviation, or they've
already
> been trying to close the airport for years.

I manage a small airport for the city in northern Wisconsin. My
neighbors are close to the runup pads, and are neither particularily
pro or con aviation, but I do have to listen to their occasional
complaints about noise & do what I can to minimize it. I find a
multiple runnup and rundown sounds annoying myself. There may be
reasons but they have their negative consequences too.

[tony roberts]

> I manage a small airport for the city in northern Wisconsin. My
> neighbors are close to the runup pads, and are neither particularily
> pro or con aviation, but I do have to listen to their occasional
> complaints about noise & do what I can to minimize it. I find a
> multiple runnup and rundown sounds annoying myself. There may be
> reasons but they have their negative consequences too.

Well you do appear to be moderating your initial position, but if pilots
running up their engines actually do create insurmountable problems with
your neighbours, then perhaps it is time to move or close your airfield.
Because the alternative is increasing the risk that one of those pilots
may just go through your neighbours roof! And to me, that is much more
unacceptable than the sound of a 30 second runup.

I also wish to add that, while there are many places in usernet where I
could see this discussion occurring, rec.aviation.piloting is certainly
not one of them. In flying, you don't learn from your mistakes - you
learn from other peoples mistakes - because it is often the first
mistake that can kill you. And if the experts say do a runup, and the
neighbours say don't, then you had better be making the right choice.
But that is just my opinion - and I learned long ago that in usernet,
even if all I say is that the sun will rise tomorrow morning, I will get
a couple of posts telling me that I don't know what I'm talking about
because it definitely won't!

So I will just continue putting the safety of my aircraft, my passengers
and myself first, while truly regretting that I may have just
inconvenienced a neighbour by having them hear my runup.

I guess on this one we'll just agree to disagree.
But I thank you for your post and your opinion.


Tony


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

[Grumman-581]

"nrp" wrote in message
ups.com...
> One I've never hear others say - I check the belly for oil before every
> flight.

Checking for oil on the belly? Hell, I would be more concerned if there
*wasn't* any there...

[Peter Duniho]

"nrp" > wrote in message
oups.com...
>> > So if a warm prop governor doesn't work, what can happen? It will
>> > either control or it won't.
>>
>> Or the failure could be causing oil to be pumped overboard.
>
> Do you get out and look afterwards to see?

You cannot test every potential failure mode. However, a runup complete
with prop check is a simple and quick thing that can detect many common
types of failures.

More relevant to my original point was that your post seems to imply the
pilot wouldn't care about a problem with the prop governor, which is
patently false. Not all prop governor failures are benign, so if one has a
chance to detect such a failure prior to takeoff, one should take that
chance.

> I manage a small airport for the city in northern Wisconsin. My
> neighbors are close to the runup pads, and are neither particularily
> pro or con aviation, but I do have to listen to their occasional
> complaints about noise & do what I can to minimize it. I find a
> multiple runnup and rundown sounds annoying myself. There may be
> reasons but they have their negative consequences too.

Well, your situation is uncommon. In any case, IMHO safety takes priority
over noise issues. Someone that close to an airport should understand that
there are consequences to being that close to an airport. If a runup
accomplished nothing, I would agree it's a pointless noise maker that ought
to be eliminated; but that's not the case.

Pete

[nrp]

> So I will just continue putting the safety of my aircraft, my
passengers
> and myself first, while truly regretting that I may have just
> inconvenienced a neighbour by having them hear my runup.
>
> I guess on this one we'll just agree to disagree.
> But I thank you for your post and your opinion.


Every airport is given an undefined noise budget from its neighbors. A
few years ago I was on the Board managing another recreational/glider
private-open-to-the-public-grass strip airport We had a lot of Cubs
etc based there with the gliders, but we had an active jump club with a
C-206 that completely used up our noise budget with the county
commissioners when we wanted to increase the number of hangars.
Although they flew the 206 as quietly as reasonable, we only had to sit
and listen while the locals said "we don't have no problems with those
Cubs and stuff - but there's that one airplane that makes all the
noise". We were happy when they left, and we got our hangars. Hasn't
been a problem since.

Safety is not being served well when an airport closes.

[John Gaquin]

"Friendly Skies" > wrote in message news:j5Oee.41392......

>.....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. .

Years ago I accumulated some 4000 hours in C402 aircraft in commuter
service. Mostly short legs, sometimes as many as 18-20 legs per day. I did
a prop cycle and mag check on every taxi-out. There is, in my view,
absolutely no reason or excuse not to. Takes about 5-6 seconds, tops. I
can understand why your friends think it is inconvenient, particularly if
they're taking 20-30 seconds to do it, but it only means they need to learn
their procedure.

JG