Landing on snow-covered grass

[Jay Honeck]

Yesterday we flew to nearby Amana (C11) to show my sister Iowa's most
popular tourist attraction, the Amana Colonies. Amana has a grass
strip -- one of the nicest in the Midwest.

We had received an inch of snow the night before -- the best kind of
snow, too, since it only "stuck' to the grass. (Any snow you don't
have to shovel is "good" snow.) Surprisingly, the temperature was
still below freezing at noon, so we would be landing on snow-covered
grass -- a rare challenge.

Mary purposefully flew a "747 pattern" to give us a nice, long,
stabilized approach. The runway at Amana is relatively short (2300
feet), and with braking action expected to be virtually nil on the
snowy grass, she wanted to touch down at minimum forward speed. This
meant three-notches of flaps, something we don't normally use in the
Pathfinder. It also meant dragging Atlas in somewhat behind the power
curve -- another tactic we normally avoid.

There are "square ponds" (waste water breathers) just off the arrival
end of Rwy 26, along with some trees -- just to make it more fun.
It's a "sporting" approach that we enjoy making a dozen or more times
per year -- but this was the first time we'd ever attempted it on
snow.

Mary skimmed over the ponds, jousting with a mild left cross wind.
She made a perfect touchdown on the sod, and rolled quickly to a
stop. The grass was a bit long, and the ground wasn't frozen, so the
added drag slowed us quickly -- one big advantage to the first snow of
the year. (Later in the year the sod will be like iron, frozen to a
depth of several feet.)

After enjoying a marvelous afternoon in Amana (their "Prelude to
Christmas" activities are always traditional and fun, and the food is
the best) it was my turn to fly us home. During preflight I
discovered that Mary had accidentally parked Atlas with the right
wheel up against a tie-down tire (hard to see in the snow), so that it
would act just like a wheel chock. Worse, the soft sod had allowed
the plane to sink in just enough so that Mary and I couldn't push it
back -- so we unloaded my sister and daughter so that they could give
us a hand.

With the four of us pushing, we were able to break Atlas free and push
him back about four feet -- enough so that I could clear the tire.
Start up was normal, and, as expected, back-taxiing on the soft, snowy
grass took considerably more power than normal. I utiliized the
"Sylvania Swing" (accelerating *away* from the direction of departure
and swinging it around while applying full throttle -- a short-field
technique that we learned at Sylvania Field in Wisconsin that can buy
you an extra several hundred feet of runway) to get off the short
field, and used classic soft-field technique to get the nose wheel out
of the snow. The cold air and Atlas' 235 horsepower did the rest, and
we climbed strongly in the cold, clear air.

After all that, landing on Iowa City's long, wide runways seemed
pretty tame...

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[RST Engineering]

Gail taught gliderguiders for several years out of Sylvania ... if you think
it is short in Assless, try it behind a Super Cub with a runout engine
towing a thousand pounds of glider {;-)

Jim




I utiliized the
> "Sylvania Swing" (accelerating *away* from the direction of departure
> and swinging it around while applying full throttle -- a short-field
> technique that we learned at Sylvania Field in Wisconsin that can buy
> you an extra several hundred feet of runway)

[Jay Honeck]

> Gail taught gliderguiders for several years out of Sylvania ... if you think
> it is short in Assless, try it behind a Super Cub with a runout engine
> towing a thousand pounds of glider {;-)

Interesting! I didn't know that she was ever in SE Wisconsin! What
year(s) was she there?

The Sylvania Swing was only necessary when we were flying our usual
clapped-out rental Cherokee 140 on a hot summer day. That thing
(N32SA -- last I heard, it's still on the line at C89) was such a dog,
and if the tires were a bit low, or we had company in the back seat,
hoochee-mama, that thing was SLOOOW to accelerate.

If you were taking off the East, those trucks on I-94 just got bigger,
and bigger, and bigger...

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[RST Engineering]

She was still teaching there when we met in '95 and as I recall, she had
been there for a couple of years. She also taught at Windy City and Clow,
living in Brookfield.

--
"If you think you can, or think you can't, you're right."
--Henry Ford


"Jay Honeck" > wrote in message
...

>> Gail taught gliderguiders for several years out of Sylvania ... if you
>> think
>> it is short in Assless, try it behind a Super Cub with a runout engine
>> towing a thousand pounds of glider {;-)
>
> Interesting! I didn't know that she was ever in SE Wisconsin! What
> year(s) was she there?

[Jay Honeck]

> She was still teaching there when we met in '95 and as I recall, she had
> been there for a couple of years. She also taught at Windy City and Clow,
> living in Brookfield.

Dang! Mary and I were flying out of Sylvania from '95 to '97, so we
almost certainly shared the pattern with her...

It's a small world...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Whiting]

Jay Honeck wrote:

> With the four of us pushing, we were able to break Atlas free and push
> him back about four feet -- enough so that I could clear the tire.
> Start up was normal, and, as expected, back-taxiing on the soft, snowy
> grass took considerably more power than normal. I utiliized the
> "Sylvania Swing" (accelerating *away* from the direction of departure
> and swinging it around while applying full throttle -- a short-field
> technique that we learned at Sylvania Field in Wisconsin that can buy
> you an extra several hundred feet of runway) to get off the short
> field, and used classic soft-field technique to get the nose wheel out
> of the snow. The cold air and Atlas' 235 horsepower did the rest, and
> we climbed strongly in the cold, clear air.

How does this buy you an extra several hundred feet of runway?

Matt

[Jay Honeck]

> How does this buy you an extra several hundred feet of runway?

If executed correctly, the Sylvania Swing means that you'll be hitting
the start of your takeoff roll already going 20 knots or more.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Dave[_3_]]

This is the same (partial) technique Art Mattison recommends when
flying out of short fields with his VG's installed ON CHEROKEES ONLY!!

I would not dare to try the rotation he suggests without the VGs, but
the "swing" really helps..

Basically...

Taxi down the upwind side of the rny and make a wide 180 deg turn at
the end . Without burning rubber, make the turn as fast as you are
comfortable. When 45 degrees to the takeoff heading, full power.

On a wide runway with good traction, you can get to 15 knts or more at
the beginning of the take off roll.

This works on Cherokees with their WIDE, SHORT and very RUGGED landing
gear. NOT RECOMMENDED for other types of aircraft.

YMMV!

Dave



On Sat, 24 Nov 2007 17:28:20 -0800 (PST), Jay Honeck
> wrote:

>> How does this buy you an extra several hundred feet of runway?
>
>If executed correctly, the Sylvania Swing means that you'll be hitting
>the start of your takeoff roll already going 20 knots or more.

[BT]

standard technique for those departing from water
a 180 turn "on the step" to get out of the shorter lakes
B

"Jay Honeck" > wrote in message
...
> Yesterday we flew to nearby Amana (C11) to show my sister Iowa's most
> popular tourist attraction, the Amana Colonies. Amana has a grass
> strip -- one of the nicest in the Midwest.
>
> We had received an inch of snow the night before -- the best kind of
> snow, too, since it only "stuck' to the grass. (Any snow you don't
> have to shovel is "good" snow.) Surprisingly, the temperature was
> still below freezing at noon, so we would be landing on snow-covered
> grass -- a rare challenge.
>
> Mary purposefully flew a "747 pattern" to give us a nice, long,
> stabilized approach. The runway at Amana is relatively short (2300
> feet), and with braking action expected to be virtually nil on the
> snowy grass, she wanted to touch down at minimum forward speed. This
> meant three-notches of flaps, something we don't normally use in the
> Pathfinder. It also meant dragging Atlas in somewhat behind the power
> curve -- another tactic we normally avoid.
>
> There are "square ponds" (waste water breathers) just off the arrival
> end of Rwy 26, along with some trees -- just to make it more fun.
> It's a "sporting" approach that we enjoy making a dozen or more times
> per year -- but this was the first time we'd ever attempted it on
> snow.
>
> Mary skimmed over the ponds, jousting with a mild left cross wind.
> She made a perfect touchdown on the sod, and rolled quickly to a
> stop. The grass was a bit long, and the ground wasn't frozen, so the
> added drag slowed us quickly -- one big advantage to the first snow of
> the year. (Later in the year the sod will be like iron, frozen to a
> depth of several feet.)
>
> After enjoying a marvelous afternoon in Amana (their "Prelude to
> Christmas" activities are always traditional and fun, and the food is
> the best) it was my turn to fly us home. During preflight I
> discovered that Mary had accidentally parked Atlas with the right
> wheel up against a tie-down tire (hard to see in the snow), so that it
> would act just like a wheel chock. Worse, the soft sod had allowed
> the plane to sink in just enough so that Mary and I couldn't push it
> back -- so we unloaded my sister and daughter so that they could give
> us a hand.
>
> With the four of us pushing, we were able to break Atlas free and push
> him back about four feet -- enough so that I could clear the tire.
> Start up was normal, and, as expected, back-taxiing on the soft, snowy
> grass took considerably more power than normal. I utiliized the
> "Sylvania Swing" (accelerating *away* from the direction of departure
> and swinging it around while applying full throttle -- a short-field
> technique that we learned at Sylvania Field in Wisconsin that can buy
> you an extra several hundred feet of runway) to get off the short
> field, and used classic soft-field technique to get the nose wheel out
> of the snow. The cold air and Atlas' 235 horsepower did the rest, and
> we climbed strongly in the cold, clear air.
>
> After all that, landing on Iowa City's long, wide runways seemed
> pretty tame...
>
> ;-)
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>
>
>
>
>

[Matt Whiting]

Jay Honeck wrote:
>> How does this buy you an extra several hundred feet of runway?
>
> If executed correctly, the Sylvania Swing means that you'll be hitting
> the start of your takeoff roll already going 20 knots or more.

I must not be visualizing correctly what you are talking about. I was
thinking it was like a J laying on its side with the long leg being the
runway and the short leg being beside the runway (assuming a pretty wide
takeoff area). You start point away from the direction of takeoff and
then make a sweeping turn onto the runway. However, if you do that wide
enough to be at 20 knots when aligned with the runway, you will have a
fairly large radius of turn and I'll bet you lose nearly as much as you
gain.

Matt

[Jay Honeck]

> I must not be visualizing correctly what you are talking about. I was
> thinking it was like a J laying on its side with the long leg being the
> runway and the short leg being beside the runway (assuming a pretty wide
> takeoff area). You start point away from the direction of takeoff and
> then make a sweeping turn onto the runway. However, if you do that wide
> enough to be at 20 knots when aligned with the runway, you will have a
> fairly large radius of turn and I'll bet you lose nearly as much as you
> gain.

You're right, if done incorrectly, you don't gain much -- although
even sloppily done, you still gain a bit.

The trick is to maintain your momentum around the "J" turn. You have
to hit the speed fast enough to maintain momentum, but not so fast
that you tip your tricycle over! As someone mentioned, Cherokees
are good for this, thanks to their wide stance. (A Tri-Pacer, for
instance, might not fare as well, with its tall, more closely spaced
gear...)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Whiting]

Jay Honeck wrote:
>> I must not be visualizing correctly what you are talking about. I was
>> thinking it was like a J laying on its side with the long leg being the
>> runway and the short leg being beside the runway (assuming a pretty wide
>> takeoff area). You start point away from the direction of takeoff and
>> then make a sweeping turn onto the runway. However, if you do that wide
>> enough to be at 20 knots when aligned with the runway, you will have a
>> fairly large radius of turn and I'll bet you lose nearly as much as you
>> gain.
>
> You're right, if done incorrectly, you don't gain much -- although
> even sloppily done, you still gain a bit.
>
> The trick is to maintain your momentum around the "J" turn. You have
> to hit the speed fast enough to maintain momentum, but not so fast
> that you tip your tricycle over! As someone mentioned, Cherokees
> are good for this, thanks to their wide stance. (A Tri-Pacer, for
> instance, might not fare as well, with its tall, more closely spaced
> gear...)

Ok, got it. Since I fly mainly Cessna airplanes, this may not help as
much. I've found that making a tight turn with my tail as close to the
end of runway as possible and then running to full throttle and RPM
before brake release works quite well, assuming the field isn't soft.

Matt

[Dale[_3_]]

In article >,
Matt Whiting > wrote:


> Ok, got it. Since I fly mainly Cessna airplanes, this may not help as
> much. I've found that making a tight turn with my tail as close to the
> end of runway as possible and then running to full throttle and RPM
> before brake release works quite well, assuming the field isn't soft.
>
> Matt

Food for thought. That holding the brakes and bringing the power up is
very costly in propellors if you operate from
dirt/grass/gravel/rock/sand/etc.

I much prefer having even 5 knots from a rolling start than any power
added before brake release.

[Dale[_3_]]

In article >,
Matt Whiting > wrote:


>
> Ok, got it. Since I fly mainly Cessna airplanes, this may not help as
> much. I've found that making a tight turn with my tail as close to the
> end of runway as possible and then running to full throttle and RPM
> before brake release works quite well, assuming the field isn't soft.
>
> Matt

Hit enter too soon on the other post.

This strip is about 700' long and exactly the width of Cessna main gear.
<G>

http://home.gci.net/~sncdfalk/flypics/ghshortfinal.jpg

[Bertie the Bunyip[_19_]]

Dale > wrote in news:notme-E6348E.12154125112007
@news.gci.net:

> In article >,
> Matt Whiting > wrote:
>
>
>>
>> Ok, got it. Since I fly mainly Cessna airplanes, this may not help as
>> much. I've found that making a tight turn with my tail as close to the
>> end of runway as possible and then running to full throttle and RPM
>> before brake release works quite well, assuming the field isn't soft.
>>
>> Matt
>
> Hit enter too soon on the other post.
>
> This strip is about 700' long and exactly the width of Cessna main gear.
> <G>
>
> http://home.gci.net/~sncdfalk/flypics/ghshortfinal.jpg
>



Cool.


Bertie

[Morgans[_2_]]

>> This strip is about 700' long and exactly the width of Cessna main gear.
>> <G>
>>
>> http://home.gci.net/~sncdfalk/flypics/ghshortfinal.jpg

That does meet the definition of a "back country strip", doesn't it.

Thing that jumped out at me was, "and it isn't even straight, when it just
as easily could have been. There must have been alcohol involved when it
got roughed out!"
--
Jim in NC

[Matt Whiting]

Dale wrote:
> In article >,
> Matt Whiting > wrote:
>
>
>> Ok, got it. Since I fly mainly Cessna airplanes, this may not help as
>> much. I've found that making a tight turn with my tail as close to the
>> end of runway as possible and then running to full throttle and RPM
>> before brake release works quite well, assuming the field isn't soft.
>>
>> Matt
>
> Food for thought. That holding the brakes and bringing the power up is
> very costly in propellors if you operate from
> dirt/grass/gravel/rock/sand/etc.
>
> I much prefer having even 5 knots from a rolling start than any power
> added before brake release.

I've heard this mentioned before, but frankly consider it an urban
legend. I've never seen a prop on a Skylane pick up anything given the
fairly generous prop clearance and I've seen many takeoff on gravel and
grass strips and made many such takeoffs myself with nary a nick.

Matt

[Dale[_3_]]

In article >,
Matt Whiting > wrote:


>
> I've heard this mentioned before, but frankly consider it an urban
> legend. I've never seen a prop on a Skylane pick up anything given the
> fairly generous prop clearance and I've seen many takeoff on gravel and
> grass strips and made many such takeoffs myself with nary a nick.
>
> Matt

LOL. Now that's funny. I've witnessed props on two occasions suffer
serious damage due to picking up a rock from the surface. Once on a
182, the other a 206.

[Dale[_3_]]

In article >,
"Morgans" > wrote:

> >> This strip is about 700' long and exactly the width of Cessna main gear.
> >> <G>
> >>
> >> http://home.gci.net/~sncdfalk/flypics/ghshortfinal.jpg
>
> That does meet the definition of a "back country strip", doesn't it.
>
> Thing that jumped out at me was, "and it isn't even straight, when it just
> as easily could have been. There must have been alcohol involved when it
> got roughed out!"

The really run part is the big whoop-dee-doo about 2/3 down the strip.
If you have much speed it throws you back into the air.

[Jay Honeck]

> LOL. Now that's funny. I've witnessed props on two occasions suffer
> serious damage due to picking up a rock from the surface. Once on a
> 182, the other a 206.

Me, too. In fact, one of the reasons I started "Friends of Iowa City
Airport" was because our taxiway was returning to gravel, and my prop
and stabilator were getting ruined.

We learned to keep the RPMs under 1000, because rocks and pebbles
won't be moved at that speed.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Gilbert Smith]

Jay Honeck > wrote:

>Yesterday we flew to nearby Amana (C11) to show my sister Iowa's most
>popular tourist attraction, the Amana Colonies. Amana has a grass
>strip -- one of the nicest in the Midwest.
>
>We had received an inch of snow the night before -- the best kind of
>snow, too, since it only "stuck' to the grass. (Any snow you don't
>have to shovel is "good" snow.) Surprisingly, the temperature was
>still below freezing at noon, so we would be landing on snow-covered
>grass -- a rare challenge.
>
>Mary purposefully flew a "747 pattern" to give us a nice, long,
>stabilized approach. The runway at Amana is relatively short (2300
>feet), and with braking action expected to be virtually nil on the
>snowy grass, she wanted to touch down at minimum forward speed. This
>meant three-notches of flaps, something we don't normally use in the
>Pathfinder. It also meant dragging Atlas in somewhat behind the power
>curve -- another tactic we normally avoid.
>
>There are "square ponds" (waste water breathers) just off the arrival
>end of Rwy 26, along with some trees -- just to make it more fun.
>It's a "sporting" approach that we enjoy making a dozen or more times
>per year -- but this was the first time we'd ever attempted it on
>snow.
>
>Mary skimmed over the ponds, jousting with a mild left cross wind.
>She made a perfect touchdown on the sod, and rolled quickly to a
>stop. The grass was a bit long, and the ground wasn't frozen, so the
>added drag slowed us quickly -- one big advantage to the first snow of
>the year. (Later in the year the sod will be like iron, frozen to a
>depth of several feet.)
>
>After enjoying a marvelous afternoon in Amana (their "Prelude to
>Christmas" activities are always traditional and fun, and the food is
>the best) it was my turn to fly us home. During preflight I
>discovered that Mary had accidentally parked Atlas with the right
>wheel up against a tie-down tire (hard to see in the snow), so that it
>would act just like a wheel chock. Worse, the soft sod had allowed
>the plane to sink in just enough so that Mary and I couldn't push it
>back -- so we unloaded my sister and daughter so that they could give
>us a hand.
>
>With the four of us pushing, we were able to break Atlas free and push
>him back about four feet -- enough so that I could clear the tire.
>Start up was normal, and, as expected, back-taxiing on the soft, snowy
>grass took considerably more power than normal. I utiliized the
>"Sylvania Swing" (accelerating *away* from the direction of departure
>and swinging it around while applying full throttle -- a short-field
>technique that we learned at Sylvania Field in Wisconsin that can buy
>you an extra several hundred feet of runway) to get off the short
>field, and used classic soft-field technique to get the nose wheel out
>of the snow. The cold air and Atlas' 235 horsepower did the rest, and
>we climbed strongly in the cold, clear air.
>
>After all that, landing on Iowa City's long, wide runways seemed
>pretty tame...
>
>;-)

A little tip if you have "lost it" on a snow covered surface.
Wait until you are sliding backwards and open the throttle.
Works a treat.

[Jay Honeck]

> A little tip if you have "lost it" on a snow covered surface.
> Wait until you are sliding backwards and open the throttle.
> Works a treat.

I've been flying off of ice and snow-covered runways for 13 years,
now, but I've thankfully never had to use THAT technique. I'll try to
remember it, though...

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Whiting]

Dale wrote:
> In article >,
> Matt Whiting > wrote:
>
>
>> I've heard this mentioned before, but frankly consider it an urban
>> legend. I've never seen a prop on a Skylane pick up anything given the
>> fairly generous prop clearance and I've seen many takeoff on gravel and
>> grass strips and made many such takeoffs myself with nary a nick.
>>
>> Matt
>
> LOL. Now that's funny. I've witnessed props on two occasions suffer
> serious damage due to picking up a rock from the surface. Once on a
> 182, the other a 206.

Yes, especially when you think a few MPH of forward speed prior to
application of full throttle will make any significant difference in the
ability of the prop to pick up a stone.

Matt

[Dale[_3_]]

In article >,
Matt Whiting > wrote:


>
> Yes, especially when you think a few MPH of forward speed prior to
> application of full throttle will make any significant difference in the
> ability of the prop to pick up a stone.
>
> Matt

I speak from experience. I had around 800 hours on my 182, the majority
of that from other than paved runways. I NEVER dinged a prop. I've
watched a lot of folks tear props up doing just what you talk
about...bringing the power up while sitting still. Trust me, it takes
very little forward motion to protect the propellor.

[Matt Whiting]

Dale wrote:
> In article >,
> Matt Whiting > wrote:
>
>
>> Yes, especially when you think a few MPH of forward speed prior to
>> application of full throttle will make any significant difference in the
>> ability of the prop to pick up a stone.
>>
>> Matt
>
> I speak from experience. I had around 800 hours on my 182, the majority
> of that from other than paved runways. I NEVER dinged a prop. I've
> watched a lot of folks tear props up doing just what you talk
> about...bringing the power up while sitting still. Trust me, it takes
> very little forward motion to protect the propellor.

I have probably 400 hours based at 7N1 (which is paved now, but was
gravel up until a couple years ago - long after I sold my airplane), and
I never dinged a prop either running to full throttle before the roll
began. Trust me, it takes no forward motion to protect the propeller
.... on a 182 anyway. I can't speak for other models.

I've never seen a single person tear up a prop doing what I suggest and
I watched hundreds and probably thousands of takeoffs at 7N1.

Matt

[Jay Honeck]

> I have probably 400 hours based at 7N1 (which is paved now, but was
> gravel up until a couple years ago - long after I sold my airplane), and
> I never dinged a prop either running to full throttle before the roll
> began. Trust me, it takes no forward motion to protect the propeller
> ... on a 182 anyway. I can't speak for other models.

So, let me see if I'm understanding you here. You're saying that
doing a full-power run up in a 182 on *gravel* won't ding your prop?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Dale[_3_]]

In article >,
Matt Whiting > wrote:


> I have probably 400 hours based at 7N1 (which is paved now, but was
> gravel up until a couple years ago - long after I sold my airplane), and
> I never dinged a prop either running to full throttle before the roll
> began. Trust me, it takes no forward motion to protect the propeller
> ... on a 182 anyway. I can't speak for other models.
>
> I've never seen a single person tear up a prop doing what I suggest and
> I watched hundreds and probably thousands of takeoffs at 7N1.
>
> Matt


Keep on believing that...just keep a good reserve for a new prop.

[Matt Whiting]

Jay Honeck wrote:
>> I have probably 400 hours based at 7N1 (which is paved now, but was
>> gravel up until a couple years ago - long after I sold my airplane), and
>> I never dinged a prop either running to full throttle before the roll
>> began. Trust me, it takes no forward motion to protect the propeller
>> ... on a 182 anyway. I can't speak for other models.
>
> So, let me see if I'm understanding you here. You're saying that
> doing a full-power run up in a 182 on *gravel* won't ding your prop?

That is my experience. Think about the relative velocity of air through
the prop at full RPM. Now think about the relative velocity of the air
through the prop when moving at the 5-10 MPH most recommend before using
full throttle. The difference is virtually nil. If you are going to
pick up gravel, you will pick it up at 10 MPH about as readily as at 0 MPH.

Matt

[Matt Whiting]

Dale wrote:
> In article >,
> Matt Whiting > wrote:
>
>
>> I have probably 400 hours based at 7N1 (which is paved now, but was
>> gravel up until a couple years ago - long after I sold my airplane), and
>> I never dinged a prop either running to full throttle before the roll
>> began. Trust me, it takes no forward motion to protect the propeller
>> ... on a 182 anyway. I can't speak for other models.
>>
>> I've never seen a single person tear up a prop doing what I suggest and
>> I watched hundreds and probably thousands of takeoffs at 7N1.
>>
>> Matt
>
>
> Keep on believing that...just keep a good reserve for a new prop.

It isn't belief. It is experience.

Matt

[Morgans[_2_]]

"Matt Whiting" > wrote

> That is my experience. Think about the relative velocity of air through
> the prop at full RPM. Now think about the relative velocity of the air
> through the prop when moving at the 5-10 MPH most recommend before using
> full throttle. The difference is virtually nil. If you are going to pick
> up gravel, you will pick it up at 10 MPH about as readily as at 0 MPH.
I'm not going to weigh in whether it is true or not.

What I have read and observed, is that a prop sitting still, after a time
will form a little "tornado" of sorts right behind the plane of the prop.
That has enough power to move gravel and debris, up and hit the prop.

When you are moving, the tornado does not have the opportunity to establish
itself as firmly, and tends to stay stationary as the plane moves past it.
--
Jim in NC

[Jay Honeck]

> That is my experience. Think about the relative velocity of air through
> the prop at full RPM. Now think about the relative velocity of the air
> through the prop when moving at the 5-10 MPH most recommend before using
> full throttle. The difference is virtually nil. If you are going to
> pick up gravel, you will pick it up at 10 MPH about as readily as at 0 MPH.

Gotcha.

Rather than peg it to a specific ground speed, I think the procedure
is more along the lines of this:

"Gradually increase throttle and RPM at a rate commensurate with the
increase in ground speed." Using this rule of thumb you might not
hit full throttle till you're 25% of the way down the runway.
(Everything depends on runway *length*, of course...)

Personally, on a loose surface I would not go to full throttle until
I'm rolling a LOT faster than 5 to 10 mph.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Dale[_3_]]

In article >,
Matt Whiting > wrote:


> It isn't belief. It is experience.
>
> Matt


Just not enough experience or perhaps not the right kind. <G>

I've seen C-130s pick up debris from the ground and the props on a C-130
are one heck of a lot farther from the ground than a Cessna prop.

The next time your sitting out there on the gravel doing a runup or
using the brakes/power short field technique have your window open.
Those little pops and clicks you're hearing are pieces of
dirt/sand/gravel/rock hitting the prop. Every single one of them is
pitting the leading edge of backside of the prop.

What I'm passing on to you I didn't make up, I learned this from people
around me, guys that make a living flying off-airport. Of my 3400 hours
about 2500 is in Alaska with the majority of that operating from other
than paved runways.

I had a great learning experience flying jumpers. We had two airplanes,
I flew the red one, Mr Roughstick flew the white one. The white one had
a ****ty looking prop and got cylinder changes each year. The red one
had a clean prop and never got a cylinder. Mr Roughstick taught me a
lot about how NOT to operate an airplane. He would use a big burst of
power to start rolling (hear that tink tink tink?), I would not use more
than 1200RPM (seems to be a magic number, don't know why) to start
rolling. There was a distinct, visible difference in the condition of
the props on the tow airplanes.