Canyon Turns

Why the flaps? Seems to add a bit of complexity to an otherwise simple
wingover.

Shawn
"MikeM" wrote in message
...
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

Larry Dighera wrote

Message-ID:
Actually the best turnaround bank angle (least altitude lost per
degree turned) is slightly above 45 degrees.

Note that all of Lowery's discussions deal with minimizing altitude
loss during a "loss of power return to the field". This is not the
same as minimizing turn radius in a canyon where altitude loss may
not be a factor and where power is still available to maintain air-
speed during the high-g turn.

Once again, I did not post post anything about a "return to the field"
but simply quoted a highly respected aerodynamics text with regard to
minimizing turn radius.

Bob Moore

"Robert Moore" wrote in message
. 8...
Larry Dighera wrote

Message-ID:
Actually the best turnaround bank angle (least altitude lost per
degree turned) is slightly above 45 degrees.

Note that all of Lowery's discussions deal with minimizing altitude
loss during a "loss of power return to the field". This is not the
same as minimizing turn radius in a canyon where altitude loss may
not be a factor and where power is still available to maintain air-
speed during the high-g turn.

Once again, I did not post post anything about a "return to the field"
but simply quoted a highly respected aerodynamics text with regard to
minimizing turn radius.

Bob Moore

Hi Bob;
There's a difference between a fighter turning at Vc (corner velocity) and a
Canyon Turn. Corner provides both maximum turn rate and minimum turn radius
ONLY if maximum available radial g is applied! Below corner the fighter is
aerodynamically limited at the Cl line, and above corner limited by the max
available load factor out to the limit LF.
A Canyon turn isn't a constant altitude turn against a maximum g like a
fighter turning at it's Vc. It's in fact, partly an unloaded turn through
the vertical plane if airspeed has to be bled, or decreasing in altitude
through the steepest part of the bank angle used if initiated below cruise.
These are the subtle differences between these two turns.
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
For personal email, please replace
the z's with e's.
dhenriquesATzarthlinkDOTnzt

My apologies for coming in late, if this has already been mentioned. How
about a chandelle or wing-over?
http://www.skyjackmotorsports.com/IAC24/aresti.html

"ShawnD2112" wrote in message news:O634c.279$pA3.40@newsfe1-win...
Why the flaps? Seems to add a bit of complexity to an otherwise simple
wingover.

Shawn

Flaps lower the stall speed, which rises markedly in a steep
turn. You need all the margin you can get.
In a 172 the first 20 degrees of flap lower the stall the most, and
the last 20 is mostly drag. We do minimum-radius turns at 70 kts, 20
flap, 60 degrees of bank.

Dan

"MikeM" wrote in message
...

Ever flown Lake Clark Pass in AK?

I wouldn't classify that as a tight canyon. You could turn a C130 around in
there.

PJ

"MikeM" wrote in message
...
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.


Maybe so. But the OP was basically describing a steep turn even if he did
call it a canyon turn.

On Thu, 11 Mar 2004, Casey Wilson wrote:

My apologies for coming in late, if this has already been mentioned. How
about a chandelle or wing-over?
http://www.skyjackmotorsports.com/IAC24/aresti.html

Cool Aresti diagrams, but... if you're really, honestly in need of a
canyon turn, you're unlikely to have the excess airspeed you need to pull
a wingover or chandelle off, and if you're turning away from rising
terrain you might not have the altitude needed to trade for the needed
airspeed either...

Sparky Imeson's "Mountain Flying Bible" points this out at least three
times; he's in favour of the 60-degree bank, with flaps up to full as
appropriate, and power as needed. Personally, doing these turns in a 172N
starting at ~80 KIAS, I've gotten the plane turned around inside the long
dimension of a high school running track that was below us - that's about
200-250ft, give or take.

Let me just throw out a plug for Mr. Imeson's great book, while I'm at it.
I've only had my copy of the "Mountain Flying Bible" for six months, but
it's already got a well-thumbed look to it. I keep my copy on the kitchen
table, and review bits and pieces when I've got a spare five minutes, in
addition to more regular reviews. (http://www.mountainflying.com/ is his
website; Amazon has his books too.)

Brian - PP-ASEL/Night -

I second you on Sparky Imeson's book, also on the low probability that, in a
relatively low-powered airplane like the 172, that you'd have enough
airspeed or altitude for a fancy canyon turn when you need it.

There is a speed (dependent on gross weight, density altitude, and flaps
configuration) called the "Banked Absolute Ceiling Speed" Vbac and a
corresponding angle, "Banked Absolute Ceiling Angle" PHIbac. If you have
those written down for a few likely cases (e.g., max gross wt., 12000 ft,
flaps up; two or three other combinations) and keep your airspeed above Vbac
and your bank below PHIbac, you can turn level. Of course that may not be a
very short radius turn (that radius should be written down in your cheat
sheet also). So you have to stay out of canyons of width narrower than twice
that turn radius.

For how to calculate all this stuff, see the Maneuvering chapter of
Performance of Light Aircraft.

John

--
John T Lowry, PhD
Flight Physics
5217 Old Spicewood Springs Rd, #312
Austin, Texas 78731
(512) 231-9391

"Brian Burger" wrote in message
ia.tc.ca...
On Thu, 11 Mar 2004, Casey Wilson wrote:

My apologies for coming in late, if this has already been mentioned.
How
about a chandelle or wing-over?
http://www.skyjackmotorsports.com/IAC24/aresti.html

Cool Aresti diagrams, but... if you're really, honestly in need of a
canyon turn, you're unlikely to have the excess airspeed you need to pull
a wingover or chandelle off, and if you're turning away from rising
terrain you might not have the altitude needed to trade for the needed
airspeed either...

Sparky Imeson's "Mountain Flying Bible" points this out at least three
times; he's in favour of the 60-degree bank, with flaps up to full as
appropriate, and power as needed. Personally, doing these turns in a 172N
starting at ~80 KIAS, I've gotten the plane turned around inside the long
dimension of a high school running track that was below us - that's about
200-250ft, give or take.

Let me just throw out a plug for Mr. Imeson's great book, while I'm at it.
I've only had my copy of the "Mountain Flying Bible" for six months, but
it's already got a well-thumbed look to it. I keep my copy on the kitchen
table, and review bits and pieces when I've got a spare five minutes, in
addition to more regular reviews. (http://www.mountainflying.com/ is his
website; Amazon has his books too.)

Brian - PP-ASEL/Night -

"Brian Burger" wrote in message
ia.tc.ca...
On Thu, 11 Mar 2004, Casey Wilson wrote:

My apologies for coming in late, if this has already been mentioned.
How
about a chandelle or wing-over?
http://www.skyjackmotorsports.com/IAC24/aresti.html

Cool Aresti diagrams, but... if you're really, honestly in need of a
canyon turn, you're unlikely to have the excess airspeed you need to pull
a wingover or chandelle off, and if you're turning away from rising
terrain you might not have the altitude needed to trade for the needed
airspeed either...

Sparky Imeson's "Mountain Flying Bible" points this out at least three
times; he's in favour of the 60-degree bank, with flaps up to full as
appropriate, and power as needed. Personally, doing these turns in a 172N
starting at ~80 KIAS, I've gotten the plane turned around inside the long
dimension of a high school running track that was below us - that's about
200-250ft, give or take.

Thanks for the book tip, Brian. First, about the mountain flying. All
my experience has been in the Southern Sierra Madre, south of Mt. Whitney,
generally, although I've poked the nose over a few other ranges and
ridgelines. Maybe I'm too conservative, but I don't fly "up" a canyon blind.
I have to pretty much know what's up there before I let the ridgelines get
above the wings. Same thing going down-canyon -- I've got to know where it
opens up.
As far as the chandelle and wing-over, I was looking for opinions. Now
you piqued my interest in horsing the club's 172S into a 60-degree-bank turn
with full-flaps. I don't remember doing that with flaps. I've got a date
with my CFII next week. I wonder if the club has parachutes....
Just to pick a nit... the straight sections of the high school track
(presuming it is around a football field) is closer to 400 feet. Still a
darn tight turn, though.