What is a "short field" for a PA28-181

kage wrote:
"Newps" wrote in message
...


kage wrote:


On any standard light aircraft wing, all best climbs (rate of climb Vy,
and angle of climb Vx) are achieved with a clean wing. Adding flaps
causes the climb angle and rate to decrease.

Not on my 182. The manual says, and I quote...

Using 20 degree wing flaps reduces the ground run and total distance over
the obstacle by approx 20 percent.



Yes over an obstacle. But that is a compromise. On a short strip the
compromise is less climb for shorter takeoff distance.

Your 182 manual NEVER says that Vx is with flaps. NOWHERE!

Vx in a 182 is clean wing. Read the POH.

kage,

You've made that statement a couple of times as if it means something. I'm not
saying it doesn't mean anything, but when you've been asked to clarify, you
respond with more authoritarian statements that don't explain. It's as if you
expect us to just accept your authority.

It seems to me that somone can define a term, say Vx, and -define- it to be
whatever he wants. OK, so then you can authoritatively say that that's what Vx
means, but so what?

The part I am missing is: supposing I accept your statement that "Vx is a clean
wing". How am I supposed to reason from that starting point to the place where
you seem to want me to go, that best angle of climb is achieved with a clean wing?

Thanks,

Dave

kage wrote:

"Newps" wrote in message
...


kage wrote:


On any standard light aircraft wing, all best climbs (rate of climb Vy,
and angle of climb Vx) are achieved with a clean wing. Adding flaps
causes the climb angle and rate to decrease.

Not on my 182. The manual says, and I quote...

Using 20 degree wing flaps reduces the ground run and total distance over
the obstacle by approx 20 percent.



Yes over an obstacle.

Well that's what were talking about...what gets me the highest in the
air in the shortest distance over the ground. My owners manual says I
get to 50 feet in 20% less distance than no flaps. Can't be more
clearer than that.


But that is a compromise.

No, it's not. I want to be the highest in the air as possible over the
shortest total ground distance. That will be with flaps 20.

"Dave Butler" wrote in message
...
kage wrote:
"Newps" wrote in message

I don't see what is difficult to understand.
Vx is defined as best angle of climb. Do you have a hard time understanding
that concept?


The Cessna's and Piper's discussed here have POH's. The older ones have
owners manuals. In each of these documents Vx is listed. It is always listed
as a clean wing speed. Do you have difficulty with "clean wing?"

Thus, anytime you lower flaps, climb angle is reduced. I know you don't want
to believe that, and you are just playing dumb. Are you too lazy to just
look in your POH?

Karl

"Newps" wrote in message
...


kage wrote:

"Newps" wrote in message
...


kage wrote:


On any standard light aircraft wing, all best climbs (rate of climb Vy,
and angle of climb Vx) are achieved with a clean wing. Adding flaps
causes the climb angle and rate to decrease.

Not on my 182. The manual says, and I quote...

Using 20 degree wing flaps reduces the ground run and total distance over
the obstacle by approx 20 percent.



Yes over an obstacle.

Well that's what were talking about...what gets me the highest in the air
in the shortest distance over the ground. My owners manual says I get to
50 feet in 20% less distance than no flaps. Can't be more clearer than
that.


But that is a compromise.

No, it's not. I want to be the highest in the air as possible over the
shortest total ground distance. That will be with flaps 20.

It is most certainly a compromise, since you never accelerate to Vx.

Your speed is just a climb speed to clear close in obsticles, and is not
related to Vx. Once clear of those close in obstacles you will want to
accelerate to Vx and retract flaps if you want to continue to climb at best
angle.

Simple concept.

On Fri, 19 Nov 2004 15:01:57 -0700, Newps wrote:



kage wrote:

"Newps" wrote in message
...


kage wrote:


On any standard light aircraft wing, all best climbs (rate of climb Vy,
and angle of climb Vx) are achieved with a clean wing. Adding flaps
causes the climb angle and rate to decrease.

Not on my 182. The manual says, and I quote...

Using 20 degree wing flaps reduces the ground run and total distance over
the obstacle by approx 20 percent.



Yes over an obstacle.

Well that's what were talking about...what gets me the highest in the
air in the shortest distance over the ground. My owners manual says I
get to 50 feet in 20% less distance than no flaps. Can't be more
clearer than that.


But that is a compromise.

No, it's not. I want to be the highest in the air as possible over the
shortest total ground distance. That will be with flaps 20.

Just can't resist jumping in here. Your climb gradient with flaps will be
lower than with zero flaps. The only reason that you do better over a 50 ft
obstacle is that your ground run is shortened so much (in a 182) that it
more than makes up for the shallower climb to 50 AGL. Most 172's, for
example, are better without flaps, even over a (standard) 50 ft obstacle
(per their POH's).

On 19 Nov 2004 12:17:45 -0800, (John Galban) wrote:

"kage" wrote in message ...

For instance, say you are taking off from a short strip in the Snake River
canyon. There are trees at the end of the runway. Most likely you will use
the short field procedure in the POH for takeoff, which will probably
include flaps. But, once clear of the trees you will want to get rid of the
flaps in order to clear the distant obstacles, such as a ridge five miles
away. Best angle is WITHOUT flaps.


Excellent point. I do a lot of flying from high DA, short, canyon
strips with tall trees at each end, and I've found that the POH
directions don't really account for all of the combinations of
conditions. Where I fly, a short field is often also a soft field.
In that case, one needs to get the wheels off the draggy surface as
soon as possible in the ground roll. This requires a combination of
the short (with obstacle clearance) and soft field procedures.

In my Cherokee, flaps definitely make a difference for clearing 75
ft. trees at the end of a grass strip. Whether it's shorter because
it gets the wheels out of the tall grass, or because of a better angle
of climb, I don't know. I do know that without flaps, the trees are
much closer to the wheels as I pass over.

It's because the wheels get out of the grass earlier, and the climb starts
farther from the trees, even if the climb angle is less than optimum.


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

Jay Somerset wrote:


Just can't resist jumping in here. Your climb gradient with flaps will be
lower than with zero flaps.

Best angle of climb is determined by what gives you the most excess thrust.
Best rate of climb is determined b what gives you the most excess power.

"Roy Page" wrote in message ink.net...
So the question is.
How long is a "short field" for a PA28-181 ? And for that matter how does
that relate to a PA28-140 with 30 less horses.

At sea level or up to maybe ~ 1500MSL field elevations and at
"reasonable" density altitudes, I'd say short field would in an Archer
would be runways under 2500' long. A few years ago before I got my
PPASEL, I used to ride often with a fellow who operated a Cherokee 140
out of a 2000' private grass strip in the middle of Texas. Even in the
summer time, the 140 had no problems with the two of us on board with
fuel to the tabs. We were nowhere near max gross however, and had no
obstacles to clear at either end of the airstrip.

Gentlemen,

I really appreciate all the informed and learned replies to my question.
I know my Archer pretty well, and have flown rental Archers for a number of
years.
The POH is totally clear on the techniques regarding take-off and the use of
flaps.
I did not intend to ask questions which the POH properly covers.
My question is much more simple.
Where can I find the definition for a "Short Field" as referred to in my
POH.
The POH makes no attempt to define the length of the short field.
That's all I need guys, Where can I find either a defined formulae or Piper
specific definition of a "Short Field"

Thanks for all the great input that this question has created.

--
Roy
N5804F - PA28-181



have pored a POH and
"One's Too Many" wrote in message
om...
"Roy Page" wrote in message
ink.net...
So the question is.
How long is a "short field" for a PA28-181 ? And for that matter how does
that relate to a PA28-140 with 30 less horses.

At sea level or up to maybe ~ 1500MSL field elevations and at
"reasonable" density altitudes, I'd say short field would in an Archer
would be runways under 2500' long. A few years ago before I got my
PPASEL, I used to ride often with a fellow who operated a Cherokee 140
out of a 2000' private grass strip in the middle of Texas. Even in the
summer time, the 140 had no problems with the two of us on board with
fuel to the tabs. We were nowhere near max gross however, and had no
obstacles to clear at either end of the airstrip.

Roy Page wrote:

Where can I find the definition for a "Short Field" as referred to in my
POH.

No such thing.


The POH makes no attempt to define the length of the short field.

Because it's a moving target. Weight, wind and air density all affect
performance.