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Canyon Turns



 
 
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  #1  
Old March 11th 04, 03:06 AM
Marc Lattoni
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Default Canyon Turns

I found a new rental opportunity at CYBW (Springbank, Alberta) with a brand
new 172SP the other day and today went out for a Mountain check ride with
the chief CFI.

Now, I did two mountain courses over the past 18 months - one with my
original training outfit and one with the local flying club. All well. Ridge
approaches, choosing the right side of the valley, updrafts, downdrafts,
lenticular clouds, rotors, 45 degrees turns, etc.

Today we did canyon turns, not at 30, not at 45 but more than 45 degrees.
Sort of standing the airplane on its wingtip as we turn.

YIKES. I just could not get it all together. What a mess. Any more of a
mess and it would have been a real mess, the kind you need soap and Lysol
for. So, no more mountain flying until I can get this right.

Anyways folks, any suggestions? I am going to try to get this right another
day.

Marc


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  #2  
Old March 11th 04, 05:05 AM
Mike Rapoport
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Default

Practice rolling the airplane into the turn slower, figure out the required
power and pitch. Keep in mind that if you start to climb or descend in a
60deg bank, the elevator won't do much. You either have to flatten out the
bank or get the pitch/power/bank right the first time. When you have that
nailed, start rolling into the turn faster. It gets fun. In real world
flying, you are probably better off with 45deg with flaps and a lower
airspeed then 60deg and a higher airspeed. Keep in mind that most planes
are rated to only +2G with the flaps extended, so don't do 60deg banks with
flaps.

Mike
MU-2

"Marc Lattoni" wrote in message
news:[email protected]
I found a new rental opportunity at CYBW (Springbank, Alberta) with a

brand
new 172SP the other day and today went out for a Mountain check ride with
the chief CFI.

Now, I did two mountain courses over the past 18 months - one with my
original training outfit and one with the local flying club. All well.

Ridge
approaches, choosing the right side of the valley, updrafts, downdrafts,
lenticular clouds, rotors, 45 degrees turns, etc.

Today we did canyon turns, not at 30, not at 45 but more than 45 degrees.
Sort of standing the airplane on its wingtip as we turn.

YIKES. I just could not get it all together. What a mess. Any more of a
mess and it would have been a real mess, the kind you need soap and Lysol
for. So, no more mountain flying until I can get this right.

Anyways folks, any suggestions? I am going to try to get this right

another
day.

Marc




  #3  
Old March 11th 04, 09:59 AM
John Harper
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Posts: n/a
Default

There's a BIG difference between 45 and 60 degree banked
turns - which is why I practice 60 degree turns, makes 45 deg
turns seem a piece of cake. You need LOTS of pull on the yoke.
Start pulling at 30, and start to pull a lot harder at 45. In my
182 it takes two hands to hold the plane level through 360 deg,
unless you retrim (which I prefer not to, although this is a matter
of taste). If the nose starts to drop, take out some of the bank
AS WELL AS pulling back.

John


"Marc Lattoni" wrote in message
news:aJQ3c.73545$[email protected]
I found a new rental opportunity at CYBW (Springbank, Alberta) with a

brand
new 172SP the other day and today went out for a Mountain check ride with
the chief CFI.

Now, I did two mountain courses over the past 18 months - one with my
original training outfit and one with the local flying club. All well.

Ridge
approaches, choosing the right side of the valley, updrafts, downdrafts,
lenticular clouds, rotors, 45 degrees turns, etc.

Today we did canyon turns, not at 30, not at 45 but more than 45 degrees.
Sort of standing the airplane on its wingtip as we turn.

YIKES. I just could not get it all together. What a mess. Any more of a
mess and it would have been a real mess, the kind you need soap and Lysol
for. So, no more mountain flying until I can get this right.

Anyways folks, any suggestions? I am going to try to get this right

another
day.

Marc




  #4  
Old March 11th 04, 02:47 PM
Robert Moore
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Default

"Marc Lattoni" wrote

Today we did canyon turns, not at 30, not at 45 but more than 45
degrees. Sort of standing the airplane on its wingtip as we turn.


Yep! We fought this battle for about two weeks last year.
There were two groups, one was the slow down and use flaps
with a shallow angle of bank and the other group (me) quoting
the aerodynamic textbook solution of flying at maneuver speed
and using about 75 degrees angle-of-bank.

Quoting from "Aerodynamics For Naval Aviators":

"The aerodynamic limit of turn radius requires that increased
velocity be utilized to produce increasing load factors and
greater angles of bank"

"The maneuver speed is the minimum speed necessary to develop
aerodynamically the limit load factor and it produces the
minimum turn radius within aerodynamic and structural limits."

Bob Moore
  #5  
Old March 11th 04, 02:59 PM
C J Campbell
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Default


The 55 degree steep turn is a required commercial maneuver. As you have
noted, it is harder than the 45 degree turn required of private pilots. It
must be maintained within five degrees of bank throughout the turn.

This is a *visual* maneuver. A lot of pilots try to look at the instruments
too much, especially the VSI. Nearly every student that I have seen who had
trouble with the 55 degree steep turn was looking at the VSI, but they don't
all realize that they are doing this. You would be amazed at how much better
they all do when I cover the instrument.

The best way to do this turn is to never look at the instruments at all.
Roll smoothly into a 55 degree bank and do not let the nose drop. You should
be able to see the slightest vertical movement of the nose against the
horizon. Let the horizon cut like a knife across the cowling -- don't let it
rise or fall in the least. Use whatever arm strength you have to hold it
there. When you roll out, the airplane will want to pitch up sharply. If you
have used trim to help you in the turn, be prepared for an even greater
pitch up moment. Anticipate this by gradually applying forward pressure on
the nose as you roll out. Again, watch the horizon on the cowling. Don't let
it rise or fall in the slightest.

The only instrument you want to even glance at is the attitude indicator. It
also will tell you whether the pitch is up or down, and confirm that you are
at the proper bank angle. Once you have confirmed that, don't look at it
again. It is not nearly as sensitive as watching the nose on horizon.


  #6  
Old March 11th 04, 03:14 PM
Teacherjh
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The only instrument you want to even glance at is the attitude indicator
[during steep turns]

IF the goal is to maintain altitude +/- 100 feet, how do you know you did that
unless you glance at the altimiter?

jOSE

--
(for Email, make the obvious changes in my address)
  #7  
Old March 11th 04, 03:20 PM
Larry Dighera
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Default

On Thu, 11 Mar 2004 14:47:43 GMT, Robert Moore
wrote in Message-Id:
:

There were two groups, one was the slow down and use flaps
with a shallow angle of bank and the other group (me) quoting
the aerodynamic textbook solution of flying at maneuver speed
and using about 75 degrees angle-of-bank.


On 4/21/2000 John T. Lowry, PhD (author of: Performance of Light
Aircraft ISBN 1-56347-330-5) said:

Message-ID:
Actually the best turnaround bank angle (least altitude lost per
degree turned) is slightly above 45 degrees. See Performance of
Light Aircraft p. 295. Rogers neglected the inclination of the
flight path angle. For GA aircraft the extra angle beyond 45
degrees is, admittedly, negligible. For a Cessna 172, flaps up, I
get 45.4 degrees for the best turnaround bank angle. Now for that
flamed-out jet fighter ...

And on 1 Nov 1999 07:11:02 -0700:
Message-ID:
Best turnaround bank angle phi (least altitude loss per angle
turned through) for a gliding airplane is given by:

cos(phi) = (sqrt(2)/2)*sqrt(1-k^2)

where k = CD0/CLmax + CLmax/(pi*e*A)

where CD0 is the parasite drag coefficient, CLmax is the maximum
lift coefficient for the airplane's flaps configuration, e is the
airplane efficiency factor, and A is the wing aspect ratio. I know
most ng readers hate those darned formulas, but that's the way the
world works.

For GA propeller-driven airplanes, k is a small number (0.116 for
a Cessna 172, flaps up) and so the best turnaround bank angle is
very closely the 45 degrees cited by Rogers and, much earlier, by
Langewiesche (Stick and Rudder, p. 358). For the above Cessna, for
instance, it's 45.4 degrees. For a flamed-out jet fighter,
however, things are considerably different.

The formulas above, along with formulas for the banked stall
speed, for banked gliding flight path angle, and for the minimum
altitude loss in a 180-degree turn, can all be found in my recent
book Performance of Light Aircraft, pp. 294-296. The following
seven pages then treat the return-to-airport maneuver, from start
of the takeoff roll to contact with the runway or terrain, in
excruciating detail. Including wind effects, the typical
four-second hesitation when the engine stops, etc.

See also:

Message-ID:

  #8  
Old March 11th 04, 03:26 PM
C J Campbell
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Posts: n/a
Default


"Teacherjh" wrote in message
...
The only instrument you want to even glance at is the attitude

indicator
[during steep turns]

IF the goal is to maintain altitude +/- 100 feet, how do you know you did

that
unless you glance at the altimiter?


If your nose does not pitch up or down then you will maintain your altitude.
You can glance at the altimeter to after you have completed the maneuver to
see how you did.


  #9  
Old March 11th 04, 03:29 PM
David
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Default

On Thu, 11 Mar 2004 14:47:43 GMT, Robert Moore
wrote:

"Marc Lattoni" wrote

Today we did canyon turns, not at 30, not at 45 but more than 45
degrees. Sort of standing the airplane on its wingtip as we turn.


Yep! We fought this battle for about two weeks last year.
There were two groups, one was the slow down and use flaps
with a shallow angle of bank and the other group (me) quoting
the aerodynamic textbook solution of flying at maneuver speed
and using about 75 degrees angle-of-bank.

Quoting from "Aerodynamics For Naval Aviators":

"The aerodynamic limit of turn radius requires that increased
velocity be utilized to produce increasing load factors and
greater angles of bank"

"The maneuver speed is the minimum speed necessary to develop
aerodynamically the limit load factor and it produces the
minimum turn radius within aerodynamic and structural limits."

Bob Moore


I have been taught two ways of making Canyon Turns.
In New Zealand I was shown a maximum performance turn. First make a
note of horizontal references then roll over 60deg, applying full
power and pull hard on elevator with both hands. The stall warning
goes off all time. It works well but I could not pull hard enough to
get stall warning to operate (C172).

The alternative way was shown to me in the USA.
Apparently called a Texas Turn, this involved reducing throttle to
idle then pitch up until in 'White Arc'. Immediately apply full flap
then full power then full rudder. Some pull on elevator but
controlling airspeed.

The former causes lots of 'G' whilst the latter has almost no 'G' and
you turn in about one wingspan, very impressive.

It has been suggested that the latter could induce a spin. I've not
had anybody confirm but it appears to be something like a 'Wingover'
maneuver but I'm not into aerobatics! Any comments?



E-mail (Remove Space after pilot): pilot
  #10  
Old March 11th 04, 05:50 PM
MikeM
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Default

C J Campbell wrote:
The 55 degree steep turn is a required commercial maneuver. As you have
noted, it is harder than the 45 degree turn required of private pilots. It


A "canyon" turn has nothing to do with a "required commercial maneuver"!
It is a last ditch manuver to get out a bad situation.

Altitude loss may be acceptable, if you have some excess to begin with.

If the canyon is narrow, start the turn as close to one wall as you dare,
about two wingspans. You should have been near the "updraft" wall before
you figured out that you need to turn around.

If you have some excess speed, first pull up into a zoom which gains
altitude, and bleeds off the speed. Canyons are usually wider higher up.

As speed decays to 1.2Vs, deploy ~15 deg of flaps, roll away from
the canyon wall to a 45-60 deg bank, use lots of rudder, dont
pull elevator until the nose drops to about 20 below horizontal.

Since you started the turn with the nose up (in the zoom), you will
be most of the way around by the time the nose has dropped.

Roll out parallel to your original course. You will feel a small
g force as you pull out of the slight dive; you can modulate the
pull out by controlling elevator back pressure.

Done this way, you will finish the turn over the center of the
canyon, where presumably the floor of the canyon is "deeper",
so you have more ground clearance.

Starting from an airspeed of ~100mph, I can turn my 182 around
in a horizontal space of about 10 wingspans, while gaining
100 to 200 ft of altitude. btw- I have practised this dozens of
times. My airplane is hangared about 10 miles from some very deep,
very long, very narrow glacier-cut canyons. Have you ever skiied
at Alta, UT? Ever flown Lake Clark Pass in AK?

MikeM
Skylane '1MM

 




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