spins from coordinated flight

I think you got me here, I cannot gin up a reference frame alibi. Let me
try this:

The airplane turns due to the horizontal component of lift. If the
horizontal component of lift
is exactly equal and opposite the apparent centrifugal force (a coordinated
turn) can the airplane
depart?

Regards
Todd

"Jose" wrote in message
. net...
Can a certificated airplane depart if the ball is precisely in the
middle[?]

If the airplane is changing heading, then it is yawing, irrespective of
the ball's position.

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

Todd W. Deckard wrote:
I think you got me here, I cannot gin up a reference frame alibi. Let me
try this:

The airplane turns due to the horizontal component of lift. If the
horizontal component of lift
is exactly equal and opposite the apparent centrifugal force (a coordinated
turn) can the airplane
depart?

Regards
Todd

"Jose" wrote in message
. net...
Can a certificated airplane depart if the ball is precisely in the
middle[?]
If the airplane is changing heading, then it is yawing, irrespective of
the ball's position.

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.


It can if you introduce an accelerated stall and a yaw rate from this turn.

--
Dudley Henriques

Todd W. Deckard wrote:
"Dudley Henriques" wrote in message
...
There is only one thing you have to know about spins. To enter one you
need 2 things to be present; stall and a yaw rate.

So to corner your answer to my question: you cannot? spin from coordinated
flight.
The airplane must be yawed during the stall break (thus the inclinometer
ball slips or skids
to one side).

My question is not to seek out practical advice in spins, or recoveries. It
is to explore two
academic debates: Can a certificated airplane depart if the ball is
precisely in the middle
and is there something telling in the emphasis from the foreign sources
cited that exposes a
gap in our US training practices and material.

Thank you for your response.

I'll be making a new years resolution to try it out in the neighboorhood
Decathalon (with an appropriate
chaperone) but as it is cold and snowy I thought I would put it to the
uunet.

Best regards,
Todd


You are correct; IF coordinated flight is being defined as ball
centered. This is indeed what is taught to most new students as they
begin flight training.....that is until they start doing slips :-))

When and if you get into aerobatics or begin flying with advanced
instructors with deep aerobatic backgrounds you learn quickly that
coordinated flight can mean cross controlled flight as well as the usual
definition with everything going ball centered in the same direction :-)
I once flew a Pitts Special the full length of a major airfield holding
it in knife edge flight. In the TRUE sense of coordinated, holding the
aircraft in knife edge would be considered as coordinated flight.

Depending on the instructor, you either learn that coordinated flight is
with the ball always in the center, or you can be taught that you are
coordinated when the control pressures are applied in the exact amount
necessary to place the airplane in the sky at the exact configuration
required at any instant in time.
I prefer the latter definition and have taught my students this way for
many years.


--
Dudley Henriques

For the purposes of my question I am referring to coordinated as:

If the horizontal component of lift is exactly equal and opposite the
apparent centrifugal force (a coordinated
turn). The pilot flying by the "seat of his or her pants" feels no skid or
slip with the seat cushion.

In your knife edge demonstration you could measure this if you rotated the
ball inclinometer 90 degrees.
I *believe* it would show you were in coordinated flight.

The Websters definition has merit for you when trying to reinforce a
fundamental learning objective
but I was trying to drive to a very specific question. Apparantly with that
I mis used "yaw"

Todd




"Dudley Henriques" wrote in message
news:QMqdnYyufd3QT-

Depending on the instructor, you either learn that coordinated flight is
with the ball always in the center, or you can be taught that you are
coordinated when the control pressures are applied in the exact amount
necessary to place the airplane in the sky at the exact configuration
required at any instant in time.

I prefer the latter definition and have taught my students this way for
many years.


--
Dudley Henriques

Todd W. Deckard wrote:

In your knife edge demonstration you could measure this if you rotated the
ball inclinometer 90 degrees.
I *believe* it would show you were in coordinated flight.

Didn't even have a ball indication in that airplane. You don't use them
in aerobatics. Even for primary instruction, it's best to get the
student's head outside the cockpit and away from the ball as soon as
possible and concentrated on nose attitude where it belongs.
Personally, I feel the ball is the least necessary instrument on the
entire panel :-)


--
Dudley Henriques

In my experience, a stall break while straight and level or in a 60 degree
bank if perfectly coordinated will drop the nose straight down.
The kicker is that 98% of the pilots have lazy feet and don't really keep
the aircraft coordinated. If power is ON, the aircraft will need more
rudder to control yaw and that amount of rudder will increase as speed is
decreased approaching the stall. Some airplanes may not have enough rudder
to stay coordinated to the stall, most pilots will not use the rudder that
is available.
Some airplanes will not spin, even wit yaw supplied by maximum rudder input
at the stall in a pro-spin direction. The Beech Skipper [BE77] requires
that the stall be entered, just before the stall, full pro-spin rudder is
applied to induce a roll. At a 90 degree bank angle, sudden and full
aileron in the opposite direction as the rudder is necessary to stall the
wing crisply at the outer half. That will cause the airplane to roll
rapidly and enter a spin. If not timed or done correctly, the aircraft will
enter a spiral.

In the accidental spin, the pilot is likely to do exactly the same thing,
just not with thought and skill. The plane is stalled while yawing
[uncoordinated] and when the break happens, the poorly trained and
non-current pilot's reaction will often be to try to pick-up the wing that
is falling and the nose with aileron and up elevator. The natural reaction,
which training and experience correct, is to "fight" the falling nose, the
falling wing, with normal control input.

IF the aircraft is coordinated perfectly, the difference in lift vector is
due slightly to the radial airspeed difference between the L&R wings, but
more my the dihedral built in the airplane. The problem is that flight is
very dynamic, control forces are changing, humans have reaction times, and
the control authority created by the aerodynamic surfaces rapidly falls with
a small decrease in airspeed [lift equation] and the other forces, such as
P-factor and engine torque involve inertia and mass.



"Todd W. Deckard" wrote in message
...
|
| "Dudley Henriques" wrote in message
| ...
| There is only one thing you have to know about spins. To enter one you
| need 2 things to be present; stall and a yaw rate.
|
| So to corner your answer to my question: you cannot? spin from
coordinated
| flight.
| The airplane must be yawed during the stall break (thus the inclinometer
| ball slips or skids
| to one side).
|
| My question is not to seek out practical advice in spins, or recoveries.
It
| is to explore two
| academic debates: Can a certificated airplane depart if the ball is
| precisely in the middle
| and is there something telling in the emphasis from the foreign sources
| cited that exposes a
| gap in our US training practices and material.
|
| Thank you for your response.
|
| I'll be making a new years resolution to try it out in the neighboorhood
| Decathalon (with an appropriate
| chaperone) but as it is cold and snowy I thought I would put it to the
| uunet.
|
| Best regards,
| Todd
|
|

clarification edit inserted
"Jim Macklin" wrote in message
...
| In my experience, a stall break while straight and level or in a 60 degree
| bank if perfectly coordinated will drop the nose straight down.
[edit--relative to the pilot, not the horizon]
| The kicker is that 98% of the pilots have lazy feet and don't really keep
| the aircraft coordinated. If power is ON, the aircraft will need more
| rudder to control yaw and that amount of rudder will increase as speed is
| decreased approaching the stall. Some airplanes may not have enough
rudder
| to stay coordinated to the stall, most pilots will not use the rudder that
| is available.
| Some airplanes will not spin, even wit yaw supplied by maximum rudder
input
| at the stall in a pro-spin direction. The Beech Skipper [BE77] requires
| that the stall be entered, just before the stall, full pro-spin rudder is
| applied to induce a roll. At a 90 degree bank angle, sudden and full
| aileron in the opposite direction as the rudder is necessary to stall the
| wing crisply at the outer half. That will cause the airplane to roll
| rapidly and enter a spin. If not timed or done correctly, the aircraft
will
| enter a spiral.
|
| In the accidental spin, the pilot is likely to do exactly the same thing,
| just not with thought and skill. The plane is stalled while yawing
| [uncoordinated] and when the break happens, the poorly trained and
| non-current pilot's reaction will often be to try to pick-up the wing that
| is falling and the nose with aileron and up elevator. The natural
reaction,
| which training and experience correct, is to "fight" the falling nose, the
| falling wing, with normal control input.
|
| IF the aircraft is coordinated perfectly, the difference in lift vector is
| due slightly to the radial airspeed difference between the L&R wings, but
| more my the dihedral built in the airplane. The problem is that flight is
| very dynamic, control forces are changing, humans have reaction times, and
| the control authority created by the aerodynamic surfaces rapidly falls
with
| a small decrease in airspeed [lift equation] and the other forces, such as
| P-factor and engine torque involve inertia and mass.
|
|
|
| "Todd W. Deckard" wrote in message
| ...
||
|| "Dudley Henriques" wrote in message
|| ...
|| There is only one thing you have to know about spins. To enter one you
|| need 2 things to be present; stall and a yaw rate.
||
|| So to corner your answer to my question: you cannot? spin from
| coordinated
|| flight.
|| The airplane must be yawed during the stall break (thus the inclinometer
|| ball slips or skids
|| to one side).
||
|| My question is not to seek out practical advice in spins, or recoveries.
| It
|| is to explore two
|| academic debates: Can a certificated airplane depart if the ball is
|| precisely in the middle
|| and is there something telling in the emphasis from the foreign sources
|| cited that exposes a
|| gap in our US training practices and material.
||
|| Thank you for your response.
||
|| I'll be making a new years resolution to try it out in the neighboorhood
|| Decathalon (with an appropriate
|| chaperone) but as it is cold and snowy I thought I would put it to the
|| uunet.
||
|| Best regards,
|| Todd
||
||
|
|

On Dec 27, 1:42 pm, "Todd W. Deckard" wrote:
Can you depart and spin from coordinated flight? Specifically a coordinated
climbing turn?



Well, yeah, prolly, but it'd have to be pretty tight. We used to spin
some glider types "over the top" as you suggest, but it's kind of
splitting hairs to suggest what you are suggesting.

And courting disaster doing a chandelle? If you're going to do a
commercial ticket you should be familair with spins intimately. An
incipient spin shouldn't even make you break a sweat.


BTW, stalls in a climbing turn are pretty much standard standard stuff
even for Private pilots.

Bertie

I have a limited exposure to spins (I've demonstrated spins or received spin
instruction in 5 different airplanes on
six different occasions). I have a commercial certificate (although you
wouldn't think so from my demonstration
of a chandelle). Maybe I did have to demonstrate a power on stall while
in a climbing 20 degree bank, once.
As I recall, we survived it.

I return to the original question: if the ball is in the middle will it
spin?

Becuase I believe snowmobile suits are for snowmobiling and not for flying I
won't have a chance to explore it
with an aerobatic instructor and an appropriate (but drafty) airplane for a
few months -- so I thought I would
put the question in a bottle and throw it in the ocean.

Regards
Todd



"Bertie the Bunyip" wrote in message
...
On Dec 27, 1:42 pm, "Todd W. Deckard" wrote:
Can you depart and spin from coordinated flight? Specifically a
coordinated
climbing turn?

And courting disaster doing a chandelle? If you're going to do a
commercial ticket you should be familair with spins intimately. An
incipient spin shouldn't even make you break a sweat.

Todd W. Deckard wrote:
I have a limited exposure to spins (I've demonstrated spins or received spin
instruction in 5 different airplanes on
six different occasions). I have a commercial certificate (although you
wouldn't think so from my demonstration
of a chandelle). Maybe I did have to demonstrate a power on stall while
in a climbing 20 degree bank, once.
As I recall, we survived it.

I return to the original question: if the ball is in the middle will it
spin?

Becuase I believe snowmobile suits are for snowmobiling and not for flying I
won't have a chance to explore it
with an aerobatic instructor and an appropriate (but drafty) airplane for a
few months -- so I thought I would
put the question in a bottle and throw it in the ocean.

Regards
Todd



"Bertie the Bunyip" wrote in message
...
On Dec 27, 1:42 pm, "Todd W. Deckard" wrote:
Can you depart and spin from coordinated flight? Specifically a
coordinated
climbing turn?

And courting disaster doing a chandelle? If you're going to do a
commercial ticket you should be familair with spins intimately. An
incipient spin shouldn't even make you break a sweat.



The answer to the ball question is no. It won't spin. A ball centered
airplane in a climbing turn is compensated by rudder and is considered
coordinated (in the classic sense).

If you introduce a climbing turn stall with the ball centered, you might
get a temporary wing drop at the break but unless you introduce a yaw
rate as the stall breaks; no yaw rate...no spin!




--
Dudley Henriques