Proping Question

"Cubdriver" usenet AT danford DOT net wrote in message
...
On 15 May 2007 14:35:47 -0700, "Robert M. Gary"
wrote:

In the C140, the Aeronca, and the J-3 the carbs (probably all
Stromburg), pulling the mixture all the way out at idle had no effect
at all on the engine.

I fly a J-3, and I've never seen one with a mixture control.


In the C-120 I flew (IIRC it was a Stromberg) the mixture lever was safety
wired in place - there was no mixture control on the panel.

--
Geoff
The Sea Hawk at Wow Way d0t Com
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On May 16, 2:52 am, Cubdriver usenet AT danford DOT net wrote:
On 15 May 2007 09:19:59 -0700, "Robert M. Gary"
wrote:

So I would pull the prop through with an
open palm hand such that if the prop did start I would be ok (some of
the old guys actually start the plane this way)

That's what I was taught to do, and what I do if I'm propping from the
front (rarely). As it happens, I was 68 at the time, but my instructor
was 21. Blue skies! -- Dan Ford

I still do the full kick when I'm actually starting the engine. Even
when I was flying the float plane and propping from the back, I'd give
a kick. Of course, if you prime the 65 cont hp engines correctly they
take almost no effort to start. I can't imagine trying to start my
Mooney that way!!

-Robert

On May 15, 2:47 pm, "Morgans" wrote:
"Robert M. Gary" wrote

BTW: I would never hand prop a nosewheel plane.

I think I know the reason for this opinion, but I would still be interested
in hearing your reasoning.

Why no hand propping a nose dragger for you?

Because the top arch of the prop is close to my head. When teaching
students to hand prop the biggest challenge is to get them to stand
close enough to the prop. Standing too far back is much more dangerous
than standing too close. The worst thing that could happen is to fall
into the prop, something that can only happen if you are standing back
and leaning into it.

-Robert

"Robert M. Gary" wrote

Because the top arch of the prop is close to my head. When teaching
students to hand prop the biggest challenge is to get them to stand
close enough to the prop. Standing too far back is much more dangerous
than standing too close. The worst thing that could happen is to fall
into the prop, something that can only happen if you are standing back
and leaning into it.

I was wrong. I had not heard that exact variation, before. g

Kicking though is still too close, even if you are swinging your body away
from the tip?
--
Jim in NC

However! I've never moved a prop unless someone was standing on the
brakes, and since if I'm propping the plane it's usually because the
guy at the controls is a stranger who probably knows little about
Cubs, I always prop from behind.

Blue skies! -- Dan Ford


I flew cubs for awhile 30+ years ago. If there was no one around to
prop yours, the drill was to stand behind the prop on the right side
and flip it with your right hand, The left was poised to adjust the
throttle when it caught. I recall that they were amazingly easy to
start (usually on the first or second try).

David Johnson

On Tue, 15 May 2007 17:47:01 -0400, "Morgans"
wrote:

Why no hand propping a nose dragger for you?

I've done it a few times but found it very awkward, as the prop on,
say, a C-150 or 172 is much lower than the prop on a taildragger like
my T-Craft.

On the T-Craft turning it backwards was the standard way of clearing
it if it was flooded... but there was no impulse coupling nor vacuum
pump.

-Dana

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Kicking though is still too close, even if you are swinging your body away
from the tip?

What exactly is "kicking"?

Jose
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On Thu, 17 May 2007 04:05:57 GMT, Jose
wrote:

Kicking though is still too close, even if you are swinging your body away
from the tip?

What exactly is "kicking"?

You're facing the prop from the front ot the plane. The blade is at
10 o'clock, at the start of a compression stroke,. You've previously
primed the engine and pulled the prop through several compressions
with the switch cold and the mixture rich.

Now you holler "Hot!, Brakes!" (assuming somebody's in the cockpit --
otherwise you switch the mags to hot and check the chocks and tiedown.

Reach up, pads of your fingers just over the top of the blade. Left
leg on ground, right leg swings forward and smartly back at the same
time that you snap the blade down. The leg swing propels your body
backward, away from the propeller arc.

That was the drill on the Taylorcraft. Cub pilots can swing the prop
from behind because of the way the doors work. I guess you'd have to
prop a T-craft on floats from behind, too, but it wouldn't be pretty
to look at.

It took the lady who sold me the plane about ten minutes to teach it
to me. It feels kinda natural. If it's a big exertion, you're doing
it wrong.

Don

On 2007-05-15 16:28:54 -0700, EridanMan said:

Interesting topic, interesting discussion... but if I may expand on
the original question a bit?

The Original piper POH that came with my bird ('67 PA-28-140) actually
recommends that that prop be pulled through two complete rotations
backwards any time the engine is started after sitting for a long time
(it actually says its a good idea for every flight, but should be
mandatory any time the engine's been sitting for a while).

I've NEVER heard or seen this advice anywhere else... I've never
practiced it... It seems almost insane to me... but the book says
what the book says.

Anyone have any clue why?

I can get the exact wording tpmogjt ... its in the 'preflight and
takeoff' section of the book.

This is also recommended in at least Cessna 172 manuals for cold
weather starts. The idea is that oil that is cold or has been sitting
awhile is thicker and more sluggish. Pulling the prop through limbers
up the oil some, so the engine does not have to work as hard while
starting. It can make all the difference in whether you are able to
start the engine or not.
--
Waddling Eagle
World Famous Flight Instructor

On 2007-05-15 07:46:15 -0700, "Dudley Henriques" said:


"Doug Palmer" wrote in message
ink.net...
Several pilots found themselves in a debate at our field yesterday. The
issue is weather it is safer to move the propeller on a (parked) aircraft
in the direction of usual engine rotation, or opposite usual rotation.
This is assuming that the propeller needs to move for some reason.

The reasonings ranged from "you should not turn an engine backwards" to
"turning the engine backwards disarms the impulse coupling", to several
issues in between.

Any thoughts from the groups collective wisdom?

This is one issue where you don't want to get bogged down in the
technicalities involving vacuum pumps and impulse couplings.
The bottom line on this issue is that you should NEVER.....EVER...... trust
a propeller not to kill you if you turn it by hand IN EITHER DIRECTION while
it's attached to the airplane.
Dudley Henriques

People will say it is technically impossible, but I think it is wishful
thinking. An engine may not run backwards very well, but I have seen
too many malfunctioning magnetos to believe that it could never happen.
It might be improbable, but I would not bet my life on the idea that it
is impossible.
--
Waddling Eagle
World Famous Flight Instructor