Stalls??

Angelo Campanella wrote:

By that I mean for laminar flow wings without stall strips, the
stall occurs at a low speed is not reversable; it really requires an
increase of speed to start flying again.

Not trying to be confrontational here, but I would rethink the way you
phrase this issue.


First of all, the stall can occur at ANY speed, and it absolutely
reversible, and it's reversible by decreasing the angle of attack below
stall. THIS is what "starts" the wing flying again...not an increase in
speed...although an increase in speed is coincident with the stall recovery.

For example, the P51 I flew had a laminar wing without stall strips and
I can assure you that just like any other airplane, the stall
characteristics of the wing were normal in every way.

--
Dudley Henriques

On Fri, 15 Feb 2008 02:44:25 -0800 (PST), D Ramapriya
wrote:

On Feb 14, 5:57 am, "Blueskies" wrote:

Every flight in a light GA single should end in a full stall...right as the wheels roll on to the runway...


Interesting... is the nosewheel strut generally designed to bear the
impact of a full-stalled landing?

Why would it need to? The nose shouldn't drop unless the pilot screws
up.



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

Ol Shy & Bashful wrote:

Why is it so many pilots are afraid of stalls? I see it over an over
when doing flight reviews and checks. Why are pilots so afraid of
flying in the low end of the speed envelope? Isn't that where the
nasty things can happen? Isn't that where a pilot should be
comfortable and competent?
What do you think?

I think that to consider stalls within the confines of the low-speed end of
the envelope is naive at best and dangerous at worst. With 24,000+ hours
you obviously know that, but after skimming through the many (many) replies
to this thread I see scant little, if any, acknowledgement that the stall
occurs at a given angle of attack (AoA), not a SPEED!

You can safely (as in not over-stress the airframe) use full control
deflection from the bottom of the green arc (usually Vs) to Vmo. At Vmo,
full elevator deflection will result in the airframe's maximum certified G
load, right before the stall. IOW, max-G and stall occur simultaneously.
Below Vmo, the wing will stall before max-G. At 1G, the wing stalls at Vs.

Here's something to really fry your noodle: at zero-G, the wing wont stall
(think about it).

My point is, stalls are an aerodynamic phenomena that is tied to the AoA,
not the ASI. I have a CFI, ATPL, aerobatics endorsements, etc, and
several thousand hours too...but all this is basic aeronautical knowledge
that is taught at ab-initio stage. Stalls shouldn't be feared, just
understood, then practised until they are as familiar as any other phase of
flight - right across the speed envelope.

BTW, you haven't lived until you've done accelerated stalls that transition
into accelerated spins! Hoo-har!!

James
--
Write yourself a threatening letter and pen a defiant reply.

"Centurion" wrote in message ...

BTW, you haven't lived until you've done accelerated stalls that transition
into accelerated spins! Hoo-har!!

James
--
Write yourself a threatening letter and pen a defiant reply.



About 1978, in a C-150 @ ~2500 agl under a cloud bank, student practicing steep turns, and I notice he is trying to hold
the nose up using top rudder, with the ball off to the left. I also notice the speed decaying, but I figure I'll let him
get a little deeper in to it. The buzzer chipped and over we go into a right snap roll and down into a spin. Piece of
cake, except this guy is bigger than I am and he froze up on the controls, yoke back and spinning. I finally busted it
loose from him and effected a recovery, and when I checked the altimeter we were at about 800'. I decided that I would
not let students get that far out of shape anymore...

Centurion wrote:
Ol Shy & Bashful wrote:

Why is it so many pilots are afraid of stalls? I see it over an over
when doing flight reviews and checks. Why are pilots so afraid of
flying in the low end of the speed envelope? Isn't that where the
nasty things can happen? Isn't that where a pilot should be
comfortable and competent?
What do you think?

I think that to consider stalls within the confines of the low-speed end of
the envelope is naive at best and dangerous at worst. With 24,000+ hours
you obviously know that, but after skimming through the many (many) replies
to this thread I see scant little, if any, acknowledgement that the stall
occurs at a given angle of attack (AoA), not a SPEED!

You can safely (as in not over-stress the airframe) use full control
deflection from the bottom of the green arc (usually Vs) to Vmo. At Vmo,
full elevator deflection will result in the airframe's maximum certified G
load, right before the stall. IOW, max-G and stall occur simultaneously.
Below Vmo, the wing will stall before max-G. At 1G, the wing stalls at Vs.

Here's something to really fry your noodle: at zero-G, the wing wont stall
(think about it).

My point is, stalls are an aerodynamic phenomena that is tied to the AoA,
not the ASI. I have a CFI, ATPL, aerobatics endorsements, etc, and
several thousand hours too...but all this is basic aeronautical knowledge
that is taught at ab-initio stage. Stalls shouldn't be feared, just
understood, then practised until they are as familiar as any other phase of
flight - right across the speed envelope.

BTW, you haven't lived until you've done accelerated stalls that transition
into accelerated spins! Hoo-har!!

James

Correct me if I'm mistaken as it's been a long long time since I've been
in a Cessna 182, ( and I'm just using a 182 as an example here out of
the inventory of everything that flies since the Vmo for the Skylane
pops into my rather feeble brain :-)) but if I remember right, the Vmo
on the Skylane was 160 KIAS. The Va or maneuvering speed on the Skylane
at GW was 111.
It's just a suggestion mind you, but I wouldn't be in all that much in a
hurry to apply full back elevator on the airplane at 160knots or Vmo
unless I wanted to crack the world record for a Cessna 182 making it
sans a few misc parts from where ever it was in the sky when I did this
to impact on the ground :-))

--
Dudley Henriques

wrote in news:c2611450-2801-4cb7-9fc9-
:

On Feb 17, 3:58*pm, Bertie the Bunyip wrote:
True, but having said that, the ASI should e regarded with some
suspicion even IMC. Most pilots ( and I did this exercise in the sim
the
other day) when presented with bad airspeed info will chase it in
preference to attitude info. this has caused lots of accidensts over
the
years. Two I can remember off the top of my head are the 757 off the
coast of Peru, I think, and the 727 in upstate new york. I'm sure
there
have been lots of others in light airplanes. It's amazing to watch.
The
airspeed sems to run away and the guy just zeroes in on it and pulls
or
pushes until the whole scene is just such a mess recovery would be a
miracle.

Yeah, worst case is when the pitot freezes over or otherwise gets
sealed off, so the ASI says you're slowing down when you're speeding
up, and vice versa (because of the changing static-port pressure as
you climb or descend). In theory, the ASI should then be out-voted by
the altimeter and the attitude indicator, but I imagine it's tricky
(I've never experienced it myself).

I have a couple of times and I had no problem, but apparently it can be.
it certainly gives you a jolt when you see it. I had it in a Twin Beech
once and the airspeed instantly went to the barberpole. Had it in some
singles as well I t doesn't take much to clog them.

That's one situation where the mushy response of a slow plane, or the
stiff controls and whooshing sound in a diving one, might be
especially helpful in augmenting what the instruments are saying (at
least for the light planes I fly--dunno how well that applies to
airliners).

It's the same, though the feel is simulated through an artificial system
that is reliant on.. you guessed it, airspeed! Older airplanes had
dedicated pitots for this ( you can see them on the fin of older
Boeings) but newer machines tend to use the air data computer which is
fed by standad pitots on the nose.

Bertie

wrote in
:

I guess I'm going to have to start (and perhaps finish) my primary
training in order to understand this comment completely.

I understand that being able to see outside helps the brain make a
connection between the behavior of the airplane and what it looks
like. However, couldn't you learn to feel the airplane and how it
behaves only on instruments ever? Could you complete a PPL without
ever looking out the window? At the risk of sounding like a simmer,
why is this "feel" so necessary when training the beginning pilot and
then relearned for an instrument rating? I know I'm making an error
of logic here (otherwise pilot training would be much different), but
what is it exactly?

I have done enough research to understand the difference between VFR,
VMC, IFR, and IMC and who and why you would fly in each one. I would
imagine this is part of training when getting a PPL. So how would a
pilot mix up these two worlds?


Well, one good reason that visual flying is a better way to go if you
are flying visually.... Umm...

Anyhow, flying instruments has, for instance, one aspect that makes it
very different and that is; you are constantly fighting a number of
signals coming from your body. I'm sure you've heard about spatial
disorientation arising from when the signal from your inner ear
conflicts with the info coming from your eyes. This never really
entirely goes away no matter how much intsrument flying you do. ( at
least it hasn't for me)
Contarily-wise, these signals are an absolute asset to a pilot flying
visually. They are working in concert with your eyes.
So the long and short of it is, when you are flying with your eyes
outside, dozens of signals that give you nothing but grief when your IMC
and soaking up a lot of your resources, are now complementing them and
aiding you in controlling the airplane.

Bertie

Angelo Campanella wrote in
:



By that I mean for laminar flow wings without stall strips, the
stall
occurs at a low speed is not reversable; it really requires an
increase of speed to start flying again. With stall strips, loss of
lift occurs at a slightly higher speed where just dropping the nose to
reduce the angle of attack will resume flying status. I suspect that
of one could fly the same plane with and without stall strips, the
bare wing would be flying all the time at the speed where the plane
with stall strips would experience the mushing... I really can't say
which plane would do which... I'm just reierating some basic
aerodynamics.

No. this just isn't so. Laminar airfoils are just like any other except
they tend to break a little more briskly.


Bertie

Dudley Henriques wrote:

Centurion wrote:
Ol Shy & Bashful wrote:

Why is it so many pilots are afraid of stalls? I see it over an over
when doing flight reviews and checks. Why are pilots so afraid of
flying in the low end of the speed envelope? Isn't that where the
nasty things can happen? Isn't that where a pilot should be
comfortable and competent?
What do you think?

I think that to consider stalls within the confines of the low-speed end
of
the envelope is naive at best and dangerous at worst. With 24,000+ hours
you obviously know that, but after skimming through the many (many)
replies to this thread I see scant little, if any, acknowledgement that
the stall occurs at a given angle of attack (AoA), not a SPEED!

You can safely (as in not over-stress the airframe) use full control
deflection from the bottom of the green arc (usually Vs) to Vmo. At Vmo,
full elevator deflection will result in the airframe's maximum certified
G
load, right before the stall. IOW, max-G and stall occur simultaneously.
Below Vmo, the wing will stall before max-G. At 1G, the wing stalls at
Vs.

Here's something to really fry your noodle: at zero-G, the wing wont
stall (think about it).

My point is, stalls are an aerodynamic phenomena that is tied to the AoA,
not the ASI. I have a CFI, ATPL, aerobatics endorsements, etc, and
several thousand hours too...but all this is basic aeronautical knowledge
that is taught at ab-initio stage. Stalls shouldn't be feared, just
understood, then practised until they are as familiar as any other phase
of flight - right across the speed envelope.

BTW, you haven't lived until you've done accelerated stalls that
transition into accelerated spins! Hoo-har!!

James

Correct me if I'm mistaken as it's been a long long time since I've been
in a Cessna 182, ( and I'm just using a 182 as an example here out of
the inventory of everything that flies since the Vmo for the Skylane
pops into my rather feeble brain :-)) but if I remember right, the Vmo
on the Skylane was 160 KIAS. The Va or maneuvering speed on the Skylane
at GW was 111.

Ooops. You're 100% correct - I mean't Va NOT Vmo! Serves me right for not
proof-reading my post :P

It's just a suggestion mind you, but I wouldn't be in all that much in a
hurry to apply full back elevator on the airplane at 160knots or Vmo
unless I wanted to crack the world record for a Cessna 182 making it
sans a few misc parts from where ever it was in the sky when I did this
to impact on the ground :-))

Indeed. That's a quite possible outcome. IIRC ultimate load for normal
category aircraft is 150% rated G (as in 1.5 times). The following thread
will be of interest to those interested in the high-speed end of the flight
envelope and how that is determined based on component failure
probabilities:
http://tinyurl.com/yrqz4f (links to http://www.eng-tips.com/)

Thanks for highlighting my misinformation

James
--
Are you making all this up as you go along?

Blueskies wrote:


"Centurion" wrote in message
...

BTW, you haven't lived until you've done accelerated stalls that
transition into accelerated spins! Hoo-har!!

James


About 1978, in a C-150 @ ~2500 agl under a cloud bank, student practicing
steep turns, and I notice he is trying to hold the nose up using top
rudder, with the ball off to the left. I also notice the speed decaying,
but I figure I'll let him get a little deeper in to it. The buzzer chipped
and over we go into a right snap roll and down into a spin. Piece of cake,
except this guy is bigger than I am and he froze up on the controls, yoke
back and spinning. I finally busted it loose from him and effected a
recovery, and when I checked the altimeter we were at about 800'. I
decided that I would not let students get that far out of shape anymore...

Yep - similar story for me, only student was climbing and trimming
for "constant back-pressure" instead of trimming out the control force.
I'd corrected him on a few flights, so thought I'd let it go and let him
see what happens. End up with the nose about 55-60deg pitch up, full power
and over it went. Student lets go of the controls and grabs me! So there
we are going round and round, down, down, down with full power. Shook him
off and recovered, but decided that accelerated spin training is probably
best left for later phases :P

You live and learn. If you do neither, you're dead.

James
--
You will triumph over your enemy.