Proping Question

On May 16, 3:05 pm, "Morgans" wrote:
"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

In a tailwheel, as you pull the prop "down" during the kick you are
also moving toward yourself (because of the angle the taildragger sits
on the ground), which helps you maintain contact as you are moving
away from it. In a nose wheel plane you'd be pushing straight down on
the prop, causing your head to move down closer to the prop arch.

-Robert

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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On May 16, 8:26 pm, Dana M. Hague
d(dash)m(dash)hague(at)comcast(dot)net wrote:
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.

I haven't yet seen a Continental or Lycoming lightplane engine
without an impulse coupling on at least one mag. That impulse
mechanism is necessary for starting because it snaps the mag over fast
so it'll generate a spark, but it also retards the spark to at or near
top dead center so that the engine doesn't kick back. The usual firing
position on an A-65 is 30 degrees before top dead center. The other,
non-impulse mag won't fire at hand-propping speeds, but will sometimes
fire immediately after the engine catches and will stop it or kick it
backwards or make it hammer frightfully until the RPM comes up to
idle. Some pilots will set the mag switch to the impulse mag only
while hand-propping, going to Both after the engine is running. Much
safer. I have two impulse mags on mine and it behaves itself.
I hand-prop using one hand only. As I pull down I fold
myself so that my weight is carried back a little. The trick, as has
been mentioned, is to get pretty close to begin with. And make sure of
your footing. Anything slippery like snow or ice or wet grass, or
gravel on the pavement, can let you slide into the prop.
I don't prime my A-65 unless the temp is down around
freezing. It floods way too easily. Mags on, throttle at idle, and it
will catch on the sixth to eighth blade.

Dan

In article .com,
wrote:

On May 16, 8:26 pm, Dana M. Hague
d(dash)m(dash)hague(at)comcast(dot)net wrote:
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.

I haven't yet seen a Continental or Lycoming lightplane engine
without an impulse coupling on at least one mag. That impulse
mechanism is necessary for starting because it snaps the mag over fast
so it'll generate a spark, but it also retards the spark to at or near
top dead center so that the engine doesn't kick back.

.........

Both mags on the O-435 Lycoming in my Johnson Rocket are non-impulse.

wrote:

I haven't yet seen a Continental or Lycoming lightplane engine
without an impulse coupling on at least one mag.

They're out there. In addition to the impuse system, there was a starting
system called "shower of sparks" that used a gadget called a vibrator to
provide the low rpm spark. Unlike the impulse system, the vibrator required
electrical power from the battery to make a spark.

I've usually seen these on older models.

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

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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

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

Doug Palmer wrote:
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?

Never, ever turn a Rotax 912/914 backwards. It
will break the suction in the oil line. To regain
oil pressure you have to undo oil lines and refill
them.

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.

In rec.aviation.student EridanMan wrote:
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.

My 63 Musketeer (BE-23) POH says the same thing:

'Always pull the propeller through by hand, opposite the direction of
rotation, several times to clear the engine and "limber up" the cold,
heavy oil before using the starter. This will also lessen the load on
the battery if external power is not used'

An old timer saw me doing that and nearly bit my head off saying that
I was going to break the vacuum pump. I felt I needed to do that in
cold weather because I was having a lot of trouble starting the
engine. I'd get maybe two revolutions before the battery died. Turned
out I needed a new starter and I had some electrical shorts too.

The vacuum pump did give up the ghost last year, but I don't think
it was related as I meekly switched to "limbering up" in the suggested
direction.

With the new starter, I don't really have any trouble starting anymore,
but I will pull it through a few times on the coldest days.

Followup set to r.a.p

--
Don Poitras