A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Aerobatics
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

spins from coordinated flight



 
 
Thread Tools Display Modes
  #11  
Old December 27th 07, 05:22 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Todd W. Deckard
external usenet poster
 
Posts: 65
Default 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.



Ads
  #12  
Old December 27th 07, 05:26 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Dudley Henriques[_2_]
external usenet poster
 
Posts: 2,546
Default spins from coordinated flight

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
  #13  
Old December 27th 07, 05:27 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Todd W. Deckard
external usenet poster
 
Posts: 65
Default spins from coordinated flight

Thanks for this, this is consistent with what I believe (however I would be
eager to be rebutted).

Todd

"Dudley Henriques" wrote in message
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



  #14  
Old December 27th 07, 05:28 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Dudley Henriques[_2_]
external usenet poster
 
Posts: 2,546
Default spins from coordinated flight

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
  #15  
Old December 27th 07, 05:31 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Todd W. Deckard
external usenet poster
 
Posts: 65
Default spins from coordinated flight


"Kyle Boatright" wrote in message
My thought is that we're splitting hairs in this thread. If the airplane
is in coordinated flight and stalls straight ahead (no wing drop), a spin
can't happen. But on most aircraft, one wing will drop first even if the
ball is centered. This wing drop creates a yaw, opening up the possibility
for a spin.


But the links that Dan_Thomas sent me indicated that the airplane would not
stall "straight ahead" if you were in a climbing turn. The outside wing
has a higher AoA
which diverges even further as it initially drops.

It was intriging to me as our vacation strip demands a short field takeoff
into a hedgerow of trees
and you'd want to be mindful of this if you stumbled into a maximum
performance evasive manuever
thru errors in planning or execution.



  #16  
Old December 27th 07, 05:38 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Dudley Henriques[_2_]
external usenet poster
 
Posts: 2,546
Default spins from coordinated flight

Kyle Boatright wrote:

"Dudley Henriques" wrote in message
...
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!



My thought is that we're splitting hairs in this thread. If the
airplane is in coordinated flight and stalls straight ahead (no wing
drop), a spin can't happen. But on most aircraft, one wing will drop
first even if the ball is centered. This wing drop creates a yaw,
opening up the possibility for a spin.





--
Dudley Henriques



The wing drop at a 1g stall is on the roll axis not the yaw axis . You
need rudder to induce the yaw rate at the stall necessary to cause entry
into auto rotation.




--
Dudley Henriques
  #17  
Old December 27th 07, 05:45 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Todd W. Deckard
external usenet poster
 
Posts: 65
Default spins from coordinated flight

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



  #18  
Old December 27th 07, 05:53 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Todd W. Deckard
external usenet poster
 
Posts: 65
Default spins from coordinated flight

I reviewed the current copy of the Private Pilot PTS and it references
"maintain heading +/- 10 degrees in straight ahead flight, *or* not to
exceed 20 degrees ... in turning flight"
It would appear that the power on stalls may be demonstrated from straight
ahead *or* climbing turns.
They are not manditory, at least in the US at the private pilot level.

Todd


"Neil Gould" wrote in message
...
Standard, and _required_ for the practical. I had to do both climbing and
descending turning stalls for my checkride. Possibly because I chose to do
my checkride in the middle of winter with an 18 kt. breeze and the
examiner didn't want to die... ;-)

Neil




  #19  
Old December 27th 07, 06:03 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Angelo Campanella
external usenet poster
 
Posts: 30
Default spins from coordinated flight



Dudley Henriques wrote:
Todd W. Deckard wrote:
I return to the original question: if the ball is in the middle will
it spin?

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!


There is a possibility that a flip to the outside can occur in a low
speed but large bank climbing turn, since the angle of attack of the
outboard wing is greater than that of the inboard wing. Thus, in a left
climbing turn of 30 degrees or maore bank, the right wing experiences a
higher angle of attack, and will stall first if the airspeed drops low
enough, and especially if an accelerated stall is induced. I have had
this demonstrated tome in a C150. The result is dramatic. The craft
flips to the right, as in a half snap roll, ends up upside down, and one
is obliged to recover by certain mens. My instructor then practiced much
back stick to get back to right side up, managing the zoom safely. It's
a bit more of a thrill and happens quicker than a conventional spin. It
can be done in both directions, plenty of altitude, please....

NOTE: If you analyze angles of attacks in urns, level, descending,
climbing, using a spiral helical surface as reference, you will see that
in turning descent, the inner wing experiences a greater angle of attack
and will fall safely to the inside of the turn, but when climbing the
oppsite wing stalls first. Te flip to upside down is a total surprise.
Hence in climbing steeply out of a takeoff, the speed, turn rate and
bank must all be carefully managed. Usually, the less the turn rate, the
better, the ball must alwys be kept centered and the airspeed must be
kept always at least 1.2 Vso or more.

A further hint is that in a cross-wind condition, especially when
higher level winds are of a changing direction (usually rotates to the
right on ascent in the northern hemisphere), it is best to make the
first turn into the wind; If you take off of RY270 and the surface wind
is from 300, the wind at 200 feet AGL will be from 310 and that at 400
feet AGL will be at 320 degrees, and likely of a higher wind speed. A
gradual right turn (10 degrees bank) will present you with increasing
airspeed and a more rapid rate of climb; wery safe and very efficient.

On descent to landing, opposite things happen. As you descend, the head
wind speed diminshes, and in the northern heispere it shifts a bit to
the left. Here in Ohio, if there is any significant surface wind, I
usually keep about 10 knots extra on early final (if Vso is 60 kts, I
carry 70 or 80 kts. When about a half mile from touchdown, I often see a
5 to 10 konot drop in airspeed with no action on my part. Crosswind
components accordingly dimiish in speed and shift a bit to the left. A
crab angle serves on the first part of final descent. If any significant
crosswind remains below 200 feet, a shift into a side slip, where
fuselage is aligned with the runway while the upwing wing is down is
best for touchdown, often on one wheel for a moment.

Angelo Campanella

  #20  
Old December 27th 07, 06:04 PM posted to rec.aviation.piloting,rec.aviation.aerobatics
Todd W. Deckard
external usenet poster
 
Posts: 65
Default spins from coordinated flight

That is to say "stall reocover while turning and climbing is not mandatory"

"Todd W. Deckard" wrote in message
...
They are not manditory, at least in the US at the private pilot level.



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
spins from coordinated flight Todd W. Deckard Piloting 61 December 29th 07 02:28 AM
Coordinated turns and the little ball Mxsmanic Piloting 51 October 11th 06 10:17 PM
Is rudder required for coordinated turns? Mxsmanic Piloting 41 September 24th 06 06:40 PM
Snap / Flick and spins in flight simulators [email protected] Simulators 1 September 2nd 06 07:10 AM
Coordinated turning stall and spins Chris OCallaghan Soaring 20 November 18th 03 09:46 PM


All times are GMT +1. The time now is 09:10 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 AviationBanter.
The comments are property of their posters.