For a while I have been wondering why there seem to be no
airplanes with a low wing and a high tail. Say for instance
with a fuselage and epenage like the Zodiac 701, but with
a low wing instead of the high wing. Then I read about deep
stall, as illustrated here:

http://www.answers.com/topic/deep-stall-png

Here deep stall is defined as a condition in which the
main wing is stalled and the stabilizer is enveloped
in the turbulent wake of the stalled wing so that
the pilot has lost pitch control and thus cannot lower
the nose to recover. For certain airframe geometries,
(such as the illustration above) that condition can
occur even if the aircraft is within the proper CG limits.

My question regards the orientation that immediately
precedes the deep stall. If the angle of attack at stall
is exactly the same as the angle that puts the stabilizer
in the shadow of the wing, that will precipitate a deep
stall, right?

What if the wing stalls at a lower AOA? Would the
stabilizer then drop into the wake?

ISTM that if the AOA that stalls the wing is higher than
the AOA that puts the stabilizer in the wake of the wing
then that aircraft is immune to this sort of deep stall,
so long as it is flying within the CG limits, right?

--

FF

"Fred the Red Shirt" > wrote in message
oups.com...
> For a while I have been wondering why there seem to be no
> airplanes with a low wing and a high tail.

Like This?

http://www.kesnat.com/DSC06717.JPG


> ISTM .....

ISTM????

On Sep 5, 6:39 pm, "El Maximo" > wrote:
> "Fred the Red Shirt" > wrote in ooglegroups.com...
>
> > For a while I have been wondering why there seem to be no
> > airplanes with a low wing and a high tail.
> > [rest of description deleted by EM]
>
> Like This?
>
> http://www.kesnat.com/DSC06717.JPG

Not quite. I was thinking of a conventional tail with the fin
and rudder extending above the stabilizer, rather than a
T-tail with the stabilizer perched on top of the fin.

That is why I described it as being like a Zodiac 701, but
with the wing dropped down to a low-wing position.

>
> > ISTM .....
>
> ISTM????

It Seems To Me.

--

FF

On Sep 5, 11:29 am, Fred the Red Shirt >
wrote:
> For a while I have been wondering why there seem to be no
> airplanes with a low wing and a high tail.

Duchess and Seminole come to mind.

On Sep 5, 12:45 pm, Fred the Red Shirt >
wrote:
> On Sep 5, 6:39 pm, "El Maximo" > wrote:
>
> > "Fred the Red Shirt" > wrote in ooglegroups.com...
>
> > > For a while I have been wondering why there seem to be no
> > > airplanes with a low wing and a high tail.
> > > [rest of description deleted by EM]
>
> > Like This?
>
> >http://www.kesnat.com/DSC06717.JPG
>
> Not quite. I was thinking of a conventional tail with the fin
> and rudder extending above the stabilizer, rather than a
> T-tail with the stabilizer perched on top of the fin.
>
> That is why I described it as being like a Zodiac 701, but
> with the wing dropped down to a low-wing position.
>
>
>
> > > ISTM .....
>
> > ISTM????
>
> It Seems To Me.
>
> --
>
> FF

Commander 112 is sort of like this if I understand what you
describing.

http://www.commander.org/

Biran

On Sep 5, 11:29 am, Fred the Red Shirt >
wrote:
> For a while I have been wondering why there seem to be no
> airplanes with a low wing and a high tail.

Tomahawk.

On Wed, 05 Sep 2007 21:18:53 -0700, Airbus > wrote:

>In article om>,
says...
>>
>>
>>On Sep 5, 11:29 am, Fred the Red Shirt >
>>wrote:
>>> For a while I have been wondering why there seem to be no
>>> airplanes with a low wing and a high tail.
>>
>>Duchess and Seminole come to mind.
>>
>
>Not to mention the DC-9 and MDxx variants
>or the KingAir200

And the Lockheed military transports.

AFIK, the only plane that had a problem with it ws the BAC 111, That
was Braniff 250 in August of 1966. But that was a case of a severe
T-storm ripping the tail off.

Don

"Fred the Red Shirt" wrote:

> For a while I have been wondering why there seem to be no
> airplanes with a low wing and a high tail.

http://tinyurl.com/2oefh6

On Wed, 05 Sep 2007 12:06:01 -0700, cjcampbell
> wrote:

>On Sep 5, 11:29 am, Fred the Red Shirt >
>wrote:
>> For a while I have been wondering why there seem to be no
>> airplanes with a low wing and a high tail.
>
>Duchess and Seminole come to mind.

doesn't have to be a "high tail". ever heard of the Cheyenne II's
stability augmentation system? didn't really do a whole lot for
controllability, primarily made it feel like there was airflow over
the elevator when there wasn't much...

one has to be exploring the edges of the envelope, but other PA31's
are able to place the tail into "bad" air also.

TC

An early model of the experimental Velocity developed this problem
during testing - ended up pancaking into a canal, iirc. Pilot
suffered back injuries but survived.

wrote:
> doesn't have to be a "high tail". ever heard of the Cheyenne II's
> stability augmentation system?



I thought it was because of the tip tanks it had to have it.

John

On Sep 6, 12:37 am, wrote:
> On Wed, 05 Sep 2007 12:06:01 -0700, cjcampbell
>
> > wrote:
> >On Sep 5, 11:29 am, Fred the Red Shirt >
> >wrote:
> >> For a while I have been wondering why there seem to be no
> >> airplanes with a low wing and a high tail.
>
> >Duchess and Seminole come to mind.
>
> doesn't have to be a "high tail". ever heard of the Cheyenne II's
> stability augmentation system? didn't really do a whole lot for
> controllability, primarily made it feel like there was airflow over
> the elevator when there wasn't much...
>
> one has to be exploring the edges of the envelope, but other PA31's
> are able to place the tail into "bad" air also.
>

This is the sort of Zodiac-like high tail I was thinking of:

http://www.icfn.net/bluesky/air1/N700RG%20-%20PIPER%20PA-31T%20CHEYENNE%20II%20(OFEK).jpg

and this is not:

http://www.dc3d.co.nz/tutorials/OFP/images/cheyenne.lllSm.GIF

Both are what I's call a "high" tail in the sense that the horizontal
stabilizer flies at a higher altitude than does the main wing, and
hence both would seem to have the same vulnerability to
deep stall.

--

FF

On Sep 6, 4:18 am, Airbus > wrote:
> In article om>,
> says...
>
>
>
> >On Sep 5, 11:29 am, Fred the Red Shirt >
> >wrote:
> >> For a while I have been wondering why there seem to be no
> >> airplanes with a low wing and a high tail.
>
> >Duchess and Seminole come to mind.
>
> Not to mention the DC-9 and MDxx variants
> or the KingAir200

All of those have T-tails.

Are you guys not familiar with the Zodiac 701?

It does not have a T-tail.

--

FF

On Sep 5, 7:31 pm, Brian > wrote:
> On Sep 5, 12:45 pm, Fred the Red Shirt >
> wrote:
>
>
>
> > On Sep 5, 6:39 pm, "El Maximo" > wrote:
>
> > > "Fred the Red Shirt" > wrote in ooglegroups.com...
>
> > > > For a while I have been wondering why there seem to be no
> > > > airplanes with a low wing and a high tail.
> > > > [rest of description deleted by EM]
>
> > > Like This?
>
> > >http://www.kesnat.com/DSC06717.JPG
>
> > Not quite. I was thinking of a conventional tail with the fin
> > and rudder extending above the stabilizer, rather than a
> > T-tail with the stabilizer perched on top of the fin.
>
> > That is why I described it as being like a Zodiac 701, but
> > with the wing dropped down to a low-wing position.
>
> > > > ISTM .....
>
> > > ISTM????
>
> > It Seems To Me.
>
> > --
>
> > FF
>
> Commander 112 is sort of like this if I understand what you
> describing.
>
> http://www.commander.org/
>

Ah yes, that looks pretty close to what I was
thinking.

--

FF

In article . com>,
says...
> For a while I have been wondering why there seem to be no
> airplanes with a low wing and a high tail. Say for instance
> with a fuselage and epenage like the Zodiac 701, but with
> a low wing instead of the high wing. Then I read about deep
> stall, as illustrated here:
>
> http://www.answers.com/topic/deep-stall-png
>
> Here deep stall is defined as a condition in which the
> main wing is stalled and the stabilizer is enveloped
> in the turbulent wake of the stalled wing so that
> the pilot has lost pitch control and thus cannot lower
> the nose to recover. For certain airframe geometries,
> (such as the illustration above) that condition can
> occur even if the aircraft is within the proper CG limits.
>
> My question regards the orientation that immediately
> precedes the deep stall. If the angle of attack at stall
> is exactly the same as the angle that puts the stabilizer
> in the shadow of the wing, that will precipitate a deep
> stall, right?
>
> What if the wing stalls at a lower AOA? Would the
> stabilizer then drop into the wake?
>
> ISTM that if the AOA that stalls the wing is higher than
> the AOA that puts the stabilizer in the wake of the wing
> then that aircraft is immune to this sort of deep stall,
> so long as it is flying within the CG limits, right?

Only Robert's mentioned the Traumahawk - which surely remains one of the
most popular/common training aircraft today.

I did all my ab-initio training in a Tomahawk, it's a great plane to
learn stalls and spins in, with it's sharp wing drop characteristics.

I went out one day and learnt to recover from spins under the hood - my
instructor told me my recovery atitudes were fairly radicle (pointing
almost straight up), but that I had read enough into the lag to nose
over and recover to straight and level (before stalling and possibly
spinning again). I had a lot of fun and my instructor got some laughs
out of it.

He tried some very dissorientating manuevoures that I was to recover
from, the worst was using a partial panel (no AH) going into a half
roll, and letting me recover from upside down (I had no sensation of the
attitude I was in). I am pleased to report that my intructor never had
to take control of the a/c - eg. I never wound the airspeed to redline.

Anyway, back on topic, I've never noted any significant blanketing
effect in the Tomahawk in any flight condition.

Maybe I'm re-opening a can of worms, but I've also never noted any
blanketing effect (again of significance, which is important I think) in
a C-172 on the elevator when sideslipping. My instructor(s) have never
let me sideslip the C-172, but I've done it myself to see the effect
above 4,000' AGL - and I can't make it happen at any airspeed.

--
Duncan

Fred the Red Shirt wrote:

>
> Here deep stall is defined as a condition in which the
> main wing is stalled and the stabilizer is enveloped
> in the turbulent wake of the stalled wing so that
> the pilot has lost pitch control and thus cannot lower
> the nose to recover. For certain airframe geometries,
> (such as the illustration above) that condition can
> occur even if the aircraft is within the proper CG limits.
>
>

Err, that's not how I see it,

The aircraft can/will still pitch down after stall for 2 reasons: First,
the center of wing lift moves aft once the wing is stalled which will
drop the nose. Second, the tail is pushing the nose up to increase angle
of attack so that once blanketed the nose drops.

As far as I understand it, all certificated aircraft must be able to
recover from a basic stall.

My 2c

Cheers

DR wrote:
> Fred the Red Shirt wrote:
>
>>
>> Here deep stall is defined as a condition in which the
>> main wing is stalled and the stabilizer is enveloped
>> in the turbulent wake of the stalled wing so that
>> the pilot has lost pitch control and thus cannot lower
>> the nose to recover. For certain airframe geometries,
>> (such as the illustration above) that condition can
>> occur even if the aircraft is within the proper CG limits.
>>
>>
>
> Err, that's not how I see it,
>
> The aircraft can/will still pitch down after stall for 2 reasons: First,
> the center of wing lift moves aft once the wing is stalled which will
> drop the nose. Second, the tail is pushing the nose up to increase angle
> of attack so that once blanketed the nose drops.
>
> As far as I understand it, all certificated aircraft must be able to
> recover from a basic stall.
>
> My 2c
>
> Cheers
Not so for the F16. Deep stall is an issue for the Viper at specific
angles of attack and cg configurations, especially if the airplane is
out of fuel balance. The result of deep stall in the Viper is a flat
extremely fast ROD either with occiliation or without.
The ONLY way to break deep stall in the Viper is to INCREASE the aoa,
then quickly input forward stick to induce a high nose rate down through
the deep stall region into a recovery.
Make no mistake, if the aoa is not increased before this fast nose down
pitch rate, the Viper will stay in deep stall and can be completely
unrecoverable.
There is no "automatic" nose down pitch rate in deep stall in the F16.


--
Dudley Henriques

On Wed, 05 Sep 2007 17:59:53 -0700, Fred the Red Shirt
> wrote in
. com>:

>> Commander 112 is sort of like this if I understand what you
>> describing.
>>
>> http://www.commander.org/
>>
>
>Ah yes, that looks pretty close to what I was
>thinking.

The Commander 112/114 has what is termed a 'cruciform empennage.

In article om>,
says...
>
>
>On Sep 5, 11:29 am, Fred the Red Shirt >
>wrote:
>> For a while I have been wondering why there seem to be no
>> airplanes with a low wing and a high tail.
>
>Duchess and Seminole come to mind.
>

Not to mention the DC-9 and MDxx variants
or the KingAir200

> Not so for the F16. Deep stall is an issue for the Viper at specific
> angles of attack and cg configurations, especially if the airplane is
> out of fuel balance. The result of deep stall in the Viper is a flat
> extremely fast ROD either with occiliation or without.
> The ONLY way to break deep stall in the Viper is to INCREASE the aoa,
> then quickly input forward stick to induce a high nose rate down through
> the deep stall region into a recovery.
> Make no mistake, if the aoa is not increased before this fast nose down
> pitch rate, the Viper will stay in deep stall and can be completely
> unrecoverable.
> There is no "automatic" nose down pitch rate in deep stall in the F16.

Your Aeronautical point is valid, but for most of us flying spam cans,
wing loadings alone dictate that the Aerodynamic forces on the
aircraft will overpower the aircrafts momentum to eventually break
free of a deep stall, as long as the aircraft is designed such that
the cL always remains behind the cG.

On Sep 6, 3:27 pm, Dudley Henriques > wrote:
> DR wrote:
> > Fred the Red Shirt wrote:
>
> >> Here deep stall is defined as a condition in which the
> >> main wing is stalled and the stabilizer is enveloped
> >> in the turbulent wake of the stalled wing so that
> >> the pilot has lost pitch control and thus cannot lower
> >> the nose to recover. For certain airframe geometries,
> >> (such as the illustration above) that condition can
> >> occur even if the aircraft is within the proper CG limits.
>
> > Err, that's not how I see it,
>
> > The aircraft can/will still pitch down after stall for 2 reasons: First,
> > the center of wing lift moves aft once the wing is stalled which will
> > drop the nose. Second, the tail is pushing the nose up to increase angle
> > of attack so that once blanketed the nose drops.
>
> > As far as I understand it, all certificated aircraft must be able to
> > recover from a basic stall.
>
> > My 2c
>
> > Cheers
>
> Not so for the F16. Deep stall is an issue for the Viper at specific
> angles of attack and cg configurations, especially if the airplane is
> out of fuel balance. The result of deep stall in the Viper is a flat
> extremely fast ROD either with occiliation or without.
> The ONLY way to break deep stall in the Viper is to INCREASE the aoa,
> then quickly input forward stick to induce a high nose rate down through
> the deep stall region into a recovery.
> Make no mistake, if the aoa is not increased before this fast nose down
> pitch rate, the Viper will stay in deep stall and can be completely
> unrecoverable.
> There is no "automatic" nose down pitch rate in deep stall in the F16.
>


The F16 elevator is in not a high configuration is it? So, how does it
get blanketed in the way the thread is discussing?

Recently, Dudley Henriques > posted:

> DR wrote:
>> Fred the Red Shirt wrote:
>>
>>>
>>> Here deep stall is defined as a condition in which the
>>> main wing is stalled and the stabilizer is enveloped
>>> in the turbulent wake of the stalled wing so that
>>> the pilot has lost pitch control and thus cannot lower
>>> the nose to recover. For certain airframe geometries,
>>> (such as the illustration above) that condition can
>>> occur even if the aircraft is within the proper CG limits.
>>>
>>>
>>
>> Err, that's not how I see it,
>>
>> The aircraft can/will still pitch down after stall for 2 reasons:
>> First, the center of wing lift moves aft once the wing is stalled
>> which will drop the nose. Second, the tail is pushing the nose up to
>> increase angle of attack so that once blanketed the nose drops.
>>
>> As far as I understand it, all certificated aircraft must be able to
>> recover from a basic stall.
>>
>> My 2c
>>
>> Cheers
> Not so for the F16. Deep stall is an issue for the Viper at specific
> angles of attack and cg configurations, especially if the airplane is
> out of fuel balance. The result of deep stall in the Viper is a flat
> extremely fast ROD either with occiliation or without.
> The ONLY way to break deep stall in the Viper is to INCREASE the aoa,
> then quickly input forward stick to induce a high nose rate down
> through the deep stall region into a recovery.
> Make no mistake, if the aoa is not increased before this fast nose
> down pitch rate, the Viper will stay in deep stall and can be
> completely unrecoverable.
> There is no "automatic" nose down pitch rate in deep stall in the F16.
>
Thank you for this explanation! One of my favorite past-times is playing
Falcon 4.0 (F-16 sim), and there have been times when I've gotten into
deep stall and have not found a way to recover. Perhaps the game is not
sophisticated enough to execute the manouver as you've described, but at
least I understand better what's happening.

More on-topic, my basic training was in a Tomahawk, and can say that the
liklihood of deep stalls in that plane are rather slim unless there is
some significant weight in the baggage area.

Neil

On Wed, 5 Sep 2007 at 21:18:53 in message
>, Airbus > wrote:
>In article om>,
says...
>>
>>
>>On Sep 5, 11:29 am, Fred the Red Shirt >
>>wrote:
>>> For a while I have been wondering why there seem to be no
>>> airplanes with a low wing and a high tail.
>>
>>Duchess and Seminole come to mind.
>>
>
>Not to mention the DC-9 and MDxx variants
>or the KingAir200
>
The deep stall first got real attention in the crash of the BAC1-11
during test flying. The full official report is included in Brian
Trubshaw's book Test Pilot. The configuration of the BAC 1-11 and the
DC-9 were very similar. The 1-11 descended almost flat with little
forward velocity until it struck the ground during a stall test flight.
All the crew were killed.

For test flying after the crash a tail parachute was installed. Part of
the trouble was the use of servo-tab elevators which at High AoA became
almost useless.

Both aircraft went on to fly safely for many years.
--
David CL Francis

In article . com>,
says...
>
>
>On Sep 6, 4:18 am, Airbus > wrote:
>> In article om>,
>> says...
>>
>>
>>
>> >On Sep 5, 11:29 am, Fred the Red Shirt >
>> >wrote:
>> >> For a while I have been wondering why there seem to be no
>> >> airplanes with a low wing and a high tail.
>>
>> >Duchess and Seminole come to mind.
>>
>> Not to mention the DC-9 and MDxx variants
>> or the KingAir200
>
>All of those have T-tails.
>
>Are you guys not familiar with the Zodiac 701?
>
>It does not have a T-tail.
>


Yet the BAC 111 (http://www.airliners.net/open.file/1255880/M/) was
famous for its deep-stall capability - or at least one high-profile
accident is attributed to this.

In article >, says...

>
>
>Yet the BAC 111 (http://www.airliners.net/open.file/1255880/M/) was
>famous for its deep-stall capability - or at least one high-profile
>accident is attributed to this.
>

And the caravelle (http://www.airliners.net/open.file/1258343/M/) to the
best of my knowledge was not particularly associated with this trait ..

Fred the Red Shirt wrote:
> On Sep 6, 12:37 am, wrote:
>> On Wed, 05 Sep 2007 12:06:01 -0700, cjcampbell
>>
>> > wrote:
>>> On Sep 5, 11:29 am, Fred the Red Shirt >
>>> wrote:
>>>> For a while I have been wondering why there seem to be no
>>>> airplanes with a low wing and a high tail.
>>
>>> Duchess and Seminole come to mind.
>>
>> doesn't have to be a "high tail". ever heard of the Cheyenne II's
>> stability augmentation system? didn't really do a whole lot for
>> controllability, primarily made it feel like there was airflow over
>> the elevator when there wasn't much...
>>
>> one has to be exploring the edges of the envelope, but other PA31's
>> are able to place the tail into "bad" air also.
>>
>
> This is the sort of Zodiac-like high tail I was thinking of:
>
> http://www.icfn.net/bluesky/air1/N700RG%20-%20PIPER%20PA-
> 31T%20CHEYENNE%20II%20(OFEK).jpg
>
> and this is not:
>
> http://www.dc3d.co.nz/tutorials/OFP/images/cheyenne.lllSm.GIF
>
> Both are what I's call a "high" tail in the sense that the horizontal
> stabilizer flies at a higher altitude than does the main wing, and
> hence both would seem to have the same vulnerability to
> deep stall.
>
> FF

If that is your definition of "high" tail you don't have to leave the Zenith
line to find a low wing that fits that description take a close look at the
601XL. Not as high as the 701 but the bottom of the horz. stabilizer is
higher than the top of the wing.

On Thu, 6 Sep 2007 06:18:24 -0500, "Neil Gould"
> wrote:

>Recently, Dudley Henriques > posted:
>
>> DR wrote:
>>> Fred the Red Shirt wrote:
>>>
>>>>
>>>> Here deep stall is defined as a condition in which the
>>>> main wing is stalled and the stabilizer is enveloped
>>>> in the turbulent wake of the stalled wing so that
>>>> the pilot has lost pitch control and thus cannot lower
>>>> the nose to recover. For certain airframe geometries,
>>>> (such as the illustration above) that condition can
>>>> occur even if the aircraft is within the proper CG limits.
>>>>
>>>>
>>>
>>> Err, that's not how I see it,
>>>
>>> The aircraft can/will still pitch down after stall for 2 reasons:
>>> First, the center of wing lift moves aft once the wing is stalled
>>> which will drop the nose. Second, the tail is pushing the nose up to
>>> increase angle of attack so that once blanketed the nose drops.
>>>
>>> As far as I understand it, all certificated aircraft must be able to
>>> recover from a basic stall.
>>>
>>> My 2c
>>>
>>> Cheers
>> Not so for the F16. Deep stall is an issue for the Viper at specific
>> angles of attack and cg configurations, especially if the airplane is
>> out of fuel balance. The result of deep stall in the Viper is a flat
>> extremely fast ROD either with occiliation or without.
>> The ONLY way to break deep stall in the Viper is to INCREASE the aoa,
>> then quickly input forward stick to induce a high nose rate down
>> through the deep stall region into a recovery.
>> Make no mistake, if the aoa is not increased before this fast nose
>> down pitch rate, the Viper will stay in deep stall and can be
>> completely unrecoverable.
>> There is no "automatic" nose down pitch rate in deep stall in the F16.
>>
>Thank you for this explanation! One of my favorite past-times is playing
>Falcon 4.0 (F-16 sim), and there have been times when I've gotten into
>deep stall and have not found a way to recover. Perhaps the game is not

The explanation as to what is happening and how to recover is in the
Falcon 4 manual.

Roger (K8RI)

>sophisticated enough to execute the manouver as you've described, but at
>least I understand better what's happening.
>
>More on-topic, my basic training was in a Tomahawk, and can say that the
>liklihood of deep stalls in that plane are rather slim unless there is
>some significant weight in the baggage area.
>
>Neil
>

In article >, DR >
wrote:

> Fred the Red Shirt wrote:
>
> >
> > Here deep stall is defined as a condition in which the
> > main wing is stalled and the stabilizer is enveloped
> > in the turbulent wake of the stalled wing so that
> > the pilot has lost pitch control and thus cannot lower
> > the nose to recover. For certain airframe geometries,
> > (such as the illustration above) that condition can
> > occur even if the aircraft is within the proper CG limits.


An additional definition of "deep stall" occurs in some twins (Twin
Comanche and Baron come to mind) is when the nacelles develop their own
positive pitching moment (up) at very high angles of attack. The result
is that the elevator has insufficient control authority to effect
recovery.

These planes have conventional mounting of the stabilizer.

The phenomenon in the F-16 described by another poster appears to be a
similar phenomenon, where the forward fuselage develops a high pitching
moment that the elevator cannot handle.

EridanMan wrote:
>> Not so for the F16. Deep stall is an issue for the Viper at specific
>> angles of attack and cg configurations, especially if the airplane is
>> out of fuel balance. The result of deep stall in the Viper is a flat
>> extremely fast ROD either with occiliation or without.
>> The ONLY way to break deep stall in the Viper is to INCREASE the aoa,
>> then quickly input forward stick to induce a high nose rate down through
>> the deep stall region into a recovery.
>> Make no mistake, if the aoa is not increased before this fast nose down
>> pitch rate, the Viper will stay in deep stall and can be completely
>> unrecoverable.
>> There is no "automatic" nose down pitch rate in deep stall in the F16.
>
> Your Aeronautical point is valid, but for most of us flying spam cans,
> wing loadings alone dictate that the Aerodynamic forces on the
> aircraft will overpower the aircrafts momentum to eventually break
> free of a deep stall, as long as the aircraft is designed such that
> the cL always remains behind the cG.
>
My comment was in response to a general statement that deep stall
results in a nose down pitch moment. This is not always the case.
Notice as well that the Viper is NOT a T tail aircraft.

--
Dudley Henriques

wrote:
> On Sep 6, 3:27 pm, Dudley Henriques > wrote:
>> DR wrote:
>>> Fred the Red Shirt wrote:
>>>> Here deep stall is defined as a condition in which the
>>>> main wing is stalled and the stabilizer is enveloped
>>>> in the turbulent wake of the stalled wing so that
>>>> the pilot has lost pitch control and thus cannot lower
>>>> the nose to recover. For certain airframe geometries,
>>>> (such as the illustration above) that condition can
>>>> occur even if the aircraft is within the proper CG limits.
>>> Err, that's not how I see it,
>>> The aircraft can/will still pitch down after stall for 2 reasons: First,
>>> the center of wing lift moves aft once the wing is stalled which will
>>> drop the nose. Second, the tail is pushing the nose up to increase angle
>>> of attack so that once blanketed the nose drops.
>>> As far as I understand it, all certificated aircraft must be able to
>>> recover from a basic stall.
>>> My 2c
>>> Cheers
>> Not so for the F16. Deep stall is an issue for the Viper at specific
>> angles of attack and cg configurations, especially if the airplane is
>> out of fuel balance. The result of deep stall in the Viper is a flat
>> extremely fast ROD either with occiliation or without.
>> The ONLY way to break deep stall in the Viper is to INCREASE the aoa,
>> then quickly input forward stick to induce a high nose rate down through
>> the deep stall region into a recovery.
>> Make no mistake, if the aoa is not increased before this fast nose down
>> pitch rate, the Viper will stay in deep stall and can be completely
>> unrecoverable.
>> There is no "automatic" nose down pitch rate in deep stall in the F16.
>>
>
>
> The F16 elevator is in not a high configuration is it? So, how does it
> get blanketed in the way the thread is discussing?
>
>
Deep stall isn't restricted to T tails. It just happens that T tails are
especially susceptible to deep stall.
Blanketing of the tail can occur in any aircraft if the design and
weight and balance scenario couples just right.
The reason you don't see deep stall in your vanilla GA airplane is
because regulations dictate specific design parameters that insure
specific stall behavior in these airplanes.

This discussion on deep stall brings up a point that I have been making
for years in the flight instruction community.
When you learn to fly, there is a natural tendency for flight
instructors to teach people to fly based on the aerodynamics involved
with the specific airplane in use for the training.
There is a whole world of aerodynamics that isn't covered when training
is accomplished in general aviation. Some students go through entire
careers as pilots not knowing how aerodynamics are affected as design
changes and airplanes fly at greater gross weights and airspeeds.

One poster correctly suggested that a pitch down moment was to be
expected in stall recovery behavior. This is correct for a Cessna or a
Piper light GA airplane manufactured in the normal or utility categories.
Just keep in mind that the design considerations for these airplanes
that handle the aerodynamics found at stall won't necessarily hold true
for the next airplane you fly.
As for the Viper; it will enter deep stall when aoa stabilizes at a high
positive or negative value outside the pitch limiter. In this stall
configuration, the Viper doesn't have full pitch authority on the
horizontal tails and won't reduce aoa enough to break the stall.
In the case of the Viper, fuel imbalance, external stores location, and
other factors that cause a rearward cg condition can cause deep stall.

The main point to make in this discussion is that the stall conditions
you learn for your Cessna 172 in training for your PPL apply to that
general category of airplane. Pilots are well advised to extend their
knowledge WELL beyond that accepted for the certificate and to delve
deeply into the new environment in which they have chosen to operate.
Learning about deep stall is a good start along that path.

--
Dudley Henriques

On Sep 6, 3:16 am, DR > wrote:
> Fred the Red Shirt wrote:
>
>
>
> > Here deep stall is defined as a condition in which the
> > main wing is stalled and the stabilizer is enveloped
> > in the turbulent wake of the stalled wing so that
> > the pilot has lost pitch control and thus cannot lower
> > the nose to recover. For certain airframe geometries,
> > (such as the illustration above) that condition can
> > occur even if the aircraft is within the proper CG limits.
>
> Err, that's not how I see it,
>
> The aircraft can/will still pitch down after stall for 2 reasons: First,
> the center of wing lift moves aft once the wing is stalled which will
> drop the nose. Second, the tail is pushing the nose up to increase angle
> of attack so that once blanketed the nose drops.

The conditions that DEFINE Deep Stall cause a loss
of lift at tail as well, though the tail is not necessarily
stalled in the same sense as the main wing.

>
> As far as I understand it, all certificated aircraft must be able to
> recover from a basic stall.
>
> My 2c
>

Deep Stall is not a basic stall. See the description
above, or the previously referenced webpage.

--

FF

On Sep 6, 12:58 pm, Airbus > wrote:
> In article . com>,
> says...
>
>
>
>
>
> >On Sep 6, 4:18 am, Airbus > wrote:
> >> In article om>,
> >> says...
>
> >> >On Sep 5, 11:29 am, Fred the Red Shirt >
> >> >wrote:
> >> >> For a while I have been wondering why there seem to be no
> >> >> airplanes with a low wing and a high tail.
>
> >> >Duchess and Seminole come to mind.
>
> >> Not to mention the DC-9 and MDxx variants
> >> or the KingAir200
>
> >All of those have T-tails.
>
> >Are you guys not familiar with the Zodiac 701?
>
> >It does not have a T-tail.
>
> Yet the BAC 111 (http://www.airliners.net/open.file/1255880/M/) was
> famous for its deep-stall capability - or at least one high-profile
> accident is attributed to this.

http://www.airliners.net/open.file/1255880/M/

Looks like A T-tail, not a cruciform tail like the Zodiac-701.

But assuming that Deep Stall is the same for a 'high' cruciform
tail as for a T-tail, how about addressing the second part,
how the aircraft gets into that condition in the first place,
and would it be avoided if stall were delayed until after the
horizonatl stabilizer passed through the wake of the main wing
during increasing AOA?

--

FF

On Sep 5, 6:39 pm, "El Maximo" > wrote:
> "Fred the Red Shirt" > wrote in ooglegroups.com...
>
> > For a while I have been wondering why there seem to be no
> > airplanes with a low wing and a high tail.
>
> Like This?
>
> http://www.kesnat.com/DSC06717.JPG
>

Perhaps your point is that if the designer wants to put the
horizontal stabilizer higher than the main wind, a T-tail is
more aerodynamically efficient than using a cruciform tail
which would put the rubber REALLY high.

--

FF

On Sep 5, 6:42 pm, Dave Doe > wrote:
> In article . com>,
> says...
>
>
>
>
>
> > For a while I have been wondering why there seem to be no
> > airplanes with a low wing and a high tail. Say for instance
> > with a fuselage and epenage like the Zodiac 701, but with
> > a low wing instead of the high wing. Then I read about deep
> > stall, as illustrated here:
>
> >http://www.answers.com/topic/deep-stall-png
>
> > Here deep stall is defined as a condition in which the
> > main wing is stalled and the stabilizer is enveloped
> > in the turbulent wake of the stalled wing so that
> > the pilot has lost pitch control and thus cannot lower
> > the nose to recover. For certain airframe geometries,
> > (such as the illustration above) that condition can
> > occur even if the aircraft is within the proper CG limits.
>
> > My question regards the orientation that immediately
> > precedes the deep stall. If the angle of attack at stall
> > is exactly the same as the angle that puts the stabilizer
> > in the shadow of the wing, that will precipitate a deep
> > stall, right?
>
> > What if the wing stalls at a lower AOA? Would the
> > stabilizer then drop into the wake?
>
> > ISTM that if the AOA that stalls the wing is higher than
> > the AOA that puts the stabilizer in the wake of the wing
> > then that aircraft is immune to this sort of deep stall,
> > so long as it is flying within the CG limits, right?
>
> Only Robert's mentioned the Traumahawk - which surely remains one of the
> most popular/common training aircraft today.
>
> I did all my ab-initio training in a Tomahawk, it's a great plane to
> learn stalls and spins in, with it's sharp wing drop characteristics.

I've provided primary training in the Tomahawk and never found any
disturbing charactersitics. Stalls were nice and straight ahead thanks
to an AD that mandated stall strips be added. Sadly I could never spin
it because the owner wouldn't allow it but I have a friend who owns
one and he spins it all the time. However, we're both a bit "gurthy"
so I can't ride along while he does the spins.

-Robert, CFII

Recently, Roger (K8RI) > posted:

> On Thu, 6 Sep 2007 06:18:24 -0500, "Neil Gould"
> > wrote:
>> [...] One of my favorite past-times is
>> playing Falcon 4.0 (F-16 sim), and there have been times when I've
>> gotten into deep stall and have not found a way to recover. Perhaps
>> the game is not
>
> The explanation as to what is happening and how to recover is in the
> Falcon 4 manual.
>
> Roger (K8RI)
>
Thanks, Roger. After looking it over, I think I was doing everything right
except hitting the MPO switch.

Neil

Recently, Nomen Nescio > posted:

> -----BEGIN PGP SIGNED MESSAGE-----
>
> From: "Neil Gould" >
>
>> Thank you for this explanation! One of my favorite past-times is
>> playing Falcon 4.0 (F-16 sim), and there have been times when I've
>> gotten into deep stall and have not found a way to recover. Perhaps
>> the game is not sophisticated enough to execute the manouver as
>> you've described, but at least I understand better what's happening.
>
> Engage the Manual Pitch Override by pressing the "O" button. Then
> increase
> the amplitude of the pitch oscillations by rocking the nose with the
> joystick. Two or three oscillations will get the nose down enough to
> get you flying, again.
>
Thanks, Nomen. After Roger's suggestion to read up on it in the manual, I
"discovered" the MPO switch. Coming from Falcon 3, I apparently didn't
read the Falcon 4 manual as thoroughly as I should.

> BTW, the first snowfall in New England
> signals the beginning of "F 4.0 dogfight season" in our house. If
> you'd be interested in a little online combat, let me know. And if
> you've got a friend with Falcon 4.0 and would like some 2 on 2
> action, my wife can also be a rather formidable adversary (and the
> best damned "wingman" I could ever ask for).
>
I would be interested in trying some online combat, and would need some
guidance to connect up via the internet. Perhaps that's in the manual, too
(although I don't see it in the index)? ;-)

Neil

On Thu, 06 Sep 2007 12:31:39 -0400, Dudley Henriques
> wrote:

<snip>

>This discussion on deep stall brings up a point that I have been making
>for years in the flight instruction community.
>When you learn to fly, there is a natural tendency for flight
>instructors to teach people to fly based on the aerodynamics involved
>with the specific airplane in use for the training.
>There is a whole world of aerodynamics that isn't covered when training
>is accomplished in general aviation. Some students go through entire
>careers as pilots not knowing how aerodynamics are affected as design
>changes and airplanes fly at greater gross weights and airspeeds.
>
>One poster correctly suggested that a pitch down moment was to be
>expected in stall recovery behavior. This is correct for a Cessna or a
>Piper light GA airplane manufactured in the normal or utility categories.
>Just keep in mind that the design considerations for these airplanes
>that handle the aerodynamics found at stall won't necessarily hold true
>for the next airplane you fly.
>As for the Viper; it will enter deep stall when aoa stabilizes at a high
>positive or negative value outside the pitch limiter. In this stall
>configuration, the Viper doesn't have full pitch authority on the
>horizontal tails and won't reduce aoa enough to break the stall.
>In the case of the Viper, fuel imbalance, external stores location, and
>other factors that cause a rearward cg condition can cause deep stall.
>
>The main point to make in this discussion is that the stall conditions
>you learn for your Cessna 172 in training for your PPL apply to that
>general category of airplane. Pilots are well advised to extend their
>knowledge WELL beyond that accepted for the certificate and to delve
>deeply into the new environment in which they have chosen to operate.
>Learning about deep stall is a good start along that path.

Which reminds me... I've let many pilots fly the Deb. A few years back
one of the locals was interested in getting a Deb or F-33 and wanted
to see how they flew. He and his wife had been flying a Cherokee 140
or 160. I think he really liked the control harmony and response as
well as the take off and landing performance, but he was used to a
very docile airplane that would let him used the ailerons in a stall.
Do that in the Deb and it'll roll over and bite you and I do mean
roll. Which ever wing you try to raise will drop *abruptly*. You can
learn to feel the stall coming in through the yoke and the stall
warning horn and light give ample warning, but there is very little
buffet with a rather abrupt break and a *strong* tendency to roll left
if you don't stop it "with the rudder". You can put it into a stall
and bring the yoke all the way back while keeping the nose pointed up
with the rudder "with practice", but it's much like balancing on a
tight rope.

I demonstrated departure, approach, and accelerated stalls and the
ease of recovery keeping everything in the proper attitude, but after
just two tries he decided he was going to stick with something like
the Cherokee and maybe upgrade to a 180 or Archer. Stall recovery is
not difficult to learn, but it is different. He didn't like the idea
of carrying power down final either. One other thing is you can't fly
it using the VSI which is poor form in any plane, but the Deb and
F-33s are so quick, using the VSI for anything other than a trend
instrument "which is its intended purpose" will put the pilot into a
PIO of 2Gs out of the bottom and zero over the top. That's typical of
both Piper and Cessna pilots the first time they fly it. There are
exceptions though.

As you say, each plane has its characteristics and they aren't
necessarily those of what we fly as trainers. These characteristics
are not unique to the Deb although it does have some of its own. With
only a few exceptions it's characteristics are common to most high
performance retracts. If flown properly it is an outstanding short
field airplane. Surprisingly although it shouldn't be, not many pilots
land the Deb and F-33s according to the POH. "Flying by the numbers"
puts them in a flight realm they learned to avoid as students and
could avoid in most of the planes they have flown. Unfortunately that
means landing these planes much faster than necessary. The Deb and
F-33 have about twice the glide ratio of a 172, but it's in the
neighborhood of 120 MPH.

I've mentioned it before, but at the Bo specific training, you should
have heard the complaining and exclamations when they told the group
the instructors would be blocking the yoke so they wouldn't be able to
use the ailerons when doing stalls.

roger (K8RI)

On Thu, 06 Sep 2007 20:49:08 -0400, john smith > wrote:

>That's the result of poor initial flight training.
>
>Roger (K8RI) wrote:
>> I've mentioned it before, but at the Bo specific training, you should
>> have heard the complaining and exclamations when they told the group
>> the instructors would be blocking the yoke so they wouldn't be able to
>> use the ailerons when doing stalls.

Yup and only 3 out of 60 pilots had done full stalls in a Bo, only two
had done accelerated stalls, and one still continued to practice them.
Only about 6 had current charts. According to the instructor I drew,
most of them were also flying final about 10 to 20 knots too fast and
of those most would be near the higher speed.

When I was first checked out in the Deb (which has tip tanks) on the
first stall it tried to roll. After that the instructor, who also
happened to fly a Deb would no longer do full stalls. So after he
signed me off to make the insurance company happy, I went out to the
practice area and spent over an hour doing nothing but stalls. (with a
little unusual attitude recover thrown in early on<g>)


Roger (K8RI)

In article >,
says...

>The deep stall first got real attention in the crash of the BAC1-11
>during test flying. The full official report is included in Brian
>Trubshaw's book Test Pilot. The configuration of the BAC 1-11 and the
>DC-9 were very similar. The 1-11 descended almost flat with little
>forward velocity until it struck the ground during a stall test flight.
>All the crew were killed.


Deep stall got further attention with the crash of the H-S Trident near
Heathrow. This is a "high" T-tail, precursor of the Boeing 727.

>From Danny Deger:
> The space shuttle could not be certified by the FAA. It pitches up when
> stalled. Due to span wise flow, the outboard portions of the wings stall
> first. Because it is a delta wing the outboard wings are also aft, so the
> center of lift moves forward.

The dreaded Pitch Divergence!


~ CT

wrote:

>>From Danny Deger:
>> The space shuttle could not be certified by the FAA. It pitches up when
>> stalled. Due to span wise flow, the outboard portions of the wings stall
>> first. Because it is a delta wing the outboard wings are also aft, so
>> the center of lift moves forward.
>
> The dreaded Pitch Divergence!

lol, the Shuttle is flying at 40 degrees angle of attack all through entry.
This is pretty much considered flying and stable in a full stall the entire
time. (except for the last little part at the end, near the runway)

The difference between Ron Paul, and all the other candidates is that Ron
Paul looks at the Market Place to see what works, instead of the FAA.
Regulations inhibited progress in favor of the status quo, or current mode
of operation. Free Markets allow for change as technology (or, our
understanding of it) improves, change that isn't limited by the
understanding or approval of some government regulator.

It has to do with risk vs reward. Yes regulation limits risk, but also
limits reward, to those who pay to have the regulations written in their
favor. Why else would the regulated, contribute to both political parties?

--
Craig Fink
Courtesy E-Mail Welcome @

On Sep 6, 9:31 am, Dudley Henriques > wrote:

> The main point to make in this discussion is that the stall conditions
> you learn for your Cessna 172 in training for your PPL apply to that
> general category of airplane. Pilots are well advised to extend their
> knowledge WELL beyond that accepted for the certificate and to delve
> deeply into the new environment in which they have chosen to operate.
> Learning about deep stall is a good start along that path.

I don't think I agree with your statement but I will say that any
pilot transitioning from the C-172 to the F-16 should ensure they get
a complete checkout.

-Robert, CFII

Robert M. Gary wrote:
> On Sep 6, 9:31 am, Dudley Henriques > wrote:
>
>> The main point to make in this discussion is that the stall conditions
>> you learn for your Cessna 172 in training for your PPL apply to that
>> general category of airplane. Pilots are well advised to extend their
>> knowledge WELL beyond that accepted for the certificate and to delve
>> deeply into the new environment in which they have chosen to operate.
>> Learning about deep stall is a good start along that path.
>
> I don't think I agree with your statement but I will say that any
> pilot transitioning from the C-172 to the F-16 should ensure they get
> a complete checkout.
>
> -Robert, CFII
>
It's helpful if instead of simply saying you disagree with something
that you go on to state exactly WHY you disagree with it. In that way
you maximize any educational value your post might have for a new pilot.

I seriously doubt that we have to worry about anyone transitioning from
a 172 to the Viper. The F16 deep stall scenario was simply used to
emphasize the fact that deep stall is not restricted to T tails which
should have been obvious.


--
Dudley Henriques

On Wed, 05 Sep 2007 20:48:38 -0400, The Visitor
> wrote:

>
>
wrote:
>> doesn't have to be a "high tail". ever heard of the Cheyenne II's
>> stability augmentation system?
>
>
>
>I thought it was because of the tip tanks it had to have it.
>
>John

nope, they've all got tip tanks. AFAIK bigger engines led to a steeper
deck angle on climb out and dirty air over the tail.

the I's don't have enuff poop to get the nose high enuff, and the XL
has a different/longer fuselage.

when the nose gets high enuff on a II, an actuator winds up the
elevator downspring so the yoke doesn't "flop". keeps the quivering
protoplasm behind the yoke from crapping him/herself when the air
leaves the elevator.

have had the same sensation in a straight 31 with a Colemill
conversion. i kinda liked it...

TC

Recently, Nomen Nescio > posted:

> -----BEGIN PGP SIGNED MESSAGE-----
>
> From: "Neil Gould" >
>
>> Thanks, Nomen. After Roger's suggestion to read up on it in the
>> manual, I "discovered" the MPO switch. Coming from Falcon 3, I
>> apparently didn't read the Falcon 4 manual as thoroughly as I should.
>
> It's kinda academic if you're in the middle of a dogfight. By the
> time you recover, you're probably a few seconds away from going up in
> a bright
> flash if you're flying against someone, with even a moderate level of
> competence with F 4.0, who managed not to stall. :)
>
I'm sure that's true, if they're on your six. ;-)

>> I would be interested in trying some online combat, and would need
>> some guidance to connect up via the internet. Perhaps that's in the
>> manual, too (although I don't see it in the index)? ;-)
>
> It's actually fairly easy.
> One person sets up a "server" within F4 (a couple of button clicks)
> and then others connect to the server via an IP number or an address.
> I've always been on the "visitor" side of the connection since
> running the "server" side can be a little problematic with a 56k
> modem that never seems to run faster than 28k. Our area just recently
> moved into the 21st century and I now have a 6 mbps cable connection
> so I should have no problem being the "server" now unless having a
> dynamic IP # screws it up.
>
I'm sure it would, as one wouldn't know their "server" IP until after
they're on-line, and even then it may not be possible to tell. The most
reliable setup would be a server with a static IP.

> You also need to have your firewall not be blocking a couple of
> ports, but that shouldn't be too difficult to do with most systems.
>
Well... it might be with mine. I'd need to know more and research the
implications before opening up my network that way.

> But if someone else has the "server" set up, all you need to do is go
> to "multiplayer", enter the address, click on "connect", and the F4.0
> program pretty much takes care of the rest and guides you through
> entering the battle.
>
> There's gotta be a few more people here on R.A.P that enjoy playing
> around
> with Falcon 4.0 and I believe a "server" can handle up to 16 planes.
> An R.A.P Dogfighting Free For All could be quite a "Hoot" if it could
> be arranged. :)
>
> But like I said, when the snow flies around here, so do the F16's. I
> should have hosting a connection figured out by then.
>
Keep me posted!

Neil