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

On Fri, 19 Nov 2004 18:15:23 -0500, Ron Natalie wrote:

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.

Absolutely correct! Have you ever seen an example where there is greater
excess thrust (at any airspeed) with flaps deployed? I suppose one could
design a wing where this was true, but I have some doubts that any (popular)
GA aircraft exhibits this behavior. Am I wrong?

On Sat, 20 Nov 2004 00:04:45 GMT, "Roy Page"
wrote:

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.

"Short field" is any field that feels, or looks short to you. It will
vary with your competency/currency in techniques.

I land my Deb at a friends sod strip and think nothing of it. OTOH I
hear: "You landed on that short little strip? Good Lord, I was
stopped in half the strip length and well over 300 feet above the
trees on the way out without straining".

That was in a conversation with a 172 pilot.
To him it was a short field. To me it wasn't.

Bring in Cherokee in steep at book speeds and it'll use very little
distance to land and stop. Probably a lot less than it'll take to get
out.

Get the book out. Do the weight and take off distance over any
obstacles for the temperature. If the take off distance at the
current conditions is going to require good short field techniques to
get out, then it is a short field. IF you are proficient on short
field techniques (and I don't mean having done them a few times) it's
no big deal, but it will leave little margin for error, or for an
engine not developing full HP.

So there are two definitions of short field. If the field seems short
enough to make the pilot consider it short (whether it is or not), or
if the TO calculations show it to require short filed techniques then
it's a short field.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

How about where the speed was between that where the wing would stall flaps
up but not flaps down?

Mike
MU-2

"Jay Somerset" wrote in message
...
On Fri, 19 Nov 2004 18:15:23 -0500, Ron Natalie wrote:

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.

Absolutely correct! Have you ever seen an example where there is greater
excess thrust (at any airspeed) with flaps deployed? I suppose one could
design a wing where this was true, but I have some doubts that any
(popular)
GA aircraft exhibits this behavior. Am I wrong?

"Jay Somerset" wrote in message
...
On 18 Nov 2004 22:28:49 GMT, (PaulaJay1) wrote:

In article PM7nd.527035$mD.5173@attbi_s02, (Ben Jackson)
writes:

I fly a warrior. If I am not doing a short field technique I usually
take off with one notch of flaps.

In the Comanche one notch of flaps makes for a much crisper transition
from rolling to flying. The takeoff angle is noticably steeper, too.


With my Archer if I put in 2 notches of flaps at 60 knots, I rise like a
helo.

For how long?

I would guess about 50ft! :-) My observations in a 172 are the same,
you can gain speed then leap up over obstacles...I believe there's a
technique where you can "leap" up over an obstacle, get to less than
the (1g) stall speed while pushing forward over the obstacle to unload the
wing (less-g = lower stall). I don't think I'd really like to try that.

If there's a headwind, wouldn't climbing at less than Vx possibly give you
a better angle of climb as seen from the ground?

Paul

"Mike Rapoport" wrote in message
nk.net...
Keep in mind that the short field settings shorten the ground run but
generally increase the distance to clear a 50' obstical.

Mmm, like others have said, I would think this is model specific.
You know when you accelerate for take-off...the increase in speed
takes proportionately longer as you get faster, so you use up much
more runway getting from 55 to 60 knots than 0-5 knots (basic
physics)...thus I would think that (for instance) if you start your
climb by lifting off at 55 knots rather than at 60, you've saved a
fair bit of runway. Usually I would guess that this distance saved
more than compensates for the slight decrease in climb angle with
flaps.

Paul

"Matt Whiting" wrote in message
...
kage wrote:
Vx in a 182 is clean wing. Read the POH.

Yes, but just because a clean wing has a certain velocity that provides
the best rate or angle in that configuration (no flaps), doesn't
necessarily mean that this is the best rate and angle that the airplane
is capable of achieving in other configurations. I don't know why Vx
and Vy are provided only in the clean configuration, but that may simply
be by definition and may not imply that this is the best that the
airplane is capable of.

Indeed. It may be useful to know what the best angle of climb speed
is with 20 degrees (or whatever) of flap.

Paul

"Roy Page" wrote in message
k.net...
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"

I'd say work out how much you're going to use without flap. If it's over the
distance available, or close, then it's a short field and you should use
flaps!

Paul

Jay Somerset wrote:
On Fri, 19 Nov 2004 18:15:23 -0500, Ron Natalie wrote:


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.


Absolutely correct! Have you ever seen an example where there is greater
excess thrust (at any airspeed) with flaps deployed? I suppose one could
design a wing where this was true, but I have some doubts that any (popular)
GA aircraft exhibits this behavior. Am I wrong?

I was agreeing with you, just throwing in a little aerodymanic theory to
the argument.

Hi,

There is no such thing as a short field. They simply do not exist.
On the other hand, there are enough too short fields :-(

-Kees

Paul Sengupta wrote:

"Jay Somerset" wrote in message
...

On 18 Nov 2004 22:28:49 GMT, (PaulaJay1) wrote:


In article PM7nd.527035$mD.5173@attbi_s02, (Ben Jackson)

writes:

I fly a warrior. If I am not doing a short field technique I usually

take off with one notch of flaps.

In the Comanche one notch of flaps makes for a much crisper transition

from rolling to flying. The takeoff angle is noticably steeper, too.

With my Archer if I put in 2 notches of flaps at 60 knots, I rise like a

helo.

For how long?


I would guess about 50ft! :-) My observations in a 172 are the same,
you can gain speed then leap up over obstacles...I believe there's a
technique where you can "leap" up over an obstacle, get to less than
the (1g) stall speed while pushing forward over the obstacle to unload the
wing (less-g = lower stall). I don't think I'd really like to try that.

If there's a headwind, wouldn't climbing at less than Vx possibly give you
a better angle of climb as seen from the ground?

Yes. The V speeds are based on calm conditions.

Matt