Glider vs. Power Pattern Bank Angle?

whereas in gliders we're taught to bank at about 45 degrees or so.

I don't think so. A "medium" turn of 30 deg. works well (gliders are
typically most roll stable near this value), is first introduced, best
rehearsed, most common (it's the famous optimum bank for "standard"
thermals), easiest to perform (Laws of Learning REPEIR, Levels of Learning
RUAC...) and gives the option to go both to a "shallow" bank of 15 deg. or a
"steep" bank of 45 deg. to adjust turn radius in progress if necessary
(maintaining good coordination and speed control) without going (at low
altitudes no less) near the parachute-wearing limit of 60 deg. or the
"abrupt..." condition of aerobatic flight. The FAA PTS does not recommend
any particular bank angle for the Landing Task, but it does define a Steep
turn Task in the Performance Maneuver Area of Operation as 45 +/-5 deg. If
that's your starting value for an ordinary turn in the pattern, how much
steeper (and more stressful) are you planning to go if your path is going
past the line of the runway?

illspam (Jim Vincent) wrote
In power, they're taught to fly patterns with very little bank angle, whereas
in gliders we're taught to bank at about 45 degrees or so. I well understand
the rationale for banking steeply in gliders, but why are power pilots taught
to do shallow turns?

Mainly because the quality of power instruction is, on the whole,
dramatically worse than the quality of glider instruction. The
majority of power instructors are low time, inexperienced pilots who
have completed a training program that takes them from zero time to
instructor (single, multi, and instrument) in less than 300 hours.
They have been taught to fly wide, power-on patterns with stabilized
power-on approaches because this is what they will be doing in the
airlines (their eventual goal) and that's what they teach their
students because they don't know anything else.

Steep turns, especially at low speed, simply scare them. Therefore,
many of them tell students not to exceed 30 degrees of bank in the
pattern.

The power-off pattern, where you bring the power to idle at about
800-1000 ft AGL and abeam the touchdown point and continue to a
landing, was once the normal pattern in general aviation for all light
trainers. Of course in such a pattern your turns will be 30-45
degrees of bank, depending on wind and how many mistakes you make.
The trainers have not changed; in fact we're mostly flying the same
ones. However, today's instructors see this as an emergency
procedure, not a normal one, because it pushes their skill level.

Michael

...instructor (single, multi, and instrument) in less than 300 hours.
They have been taught to fly wide, power-on patterns with stabilized
power-on approaches because this is what they will be doing in the
airlines (their eventual goal) and that's what they teach their
students because they don't know anything else.

No kidding! I freaked one out once during a BFR by slipping a Skylane on
short final.

Tony V

Jim wrote in message . ..
On 11 Jun 2004 05:47:17 -0700, (Brian Case) wrote:

snip

Interestingly Many Pilots (Instructors included) don't seem to realize
that many (not all) aircraft actually are much harder to stall in a
steep turn than a shallow turn. This is because unless the CG is near
or past the aft CG Limit the elevator does not have enough power to
hold the turn and stall the wing. This is somewhat supported by fact
that most stall spin accidents are not initated from a steep turn but
rather from shallow skidded turns. Generally it is actually safer to
use a steeper turn.


snip

I have experienced stall buffet at 60 degrees of bank in a thermal
in a DG-505, and I fly with a forward CG. Granted, stall buffet is
not yet a stall, and the DG's stall characteristics may be pretty
benign, but I no longer trust that a glider will be hard to stall in
steep turns. Because in a turn the inside wing is flying at a higher
AOA than the outside wing, the inside wing will likely stall, and
drop, before the outside wing. I understand that in some gliders
without the newer wing designs this inside wing stall may well be
followed an eye-blink later with an out-the-bottom spin entry.
The "Pooch" may be such a glider.

YMMV of course. I'm just glad to have noticed this.

Granted Gliders probably are more likely to stall in a steep turn than
most power aircraft due to the long wings and the larger differences
in AoA from the inside to outside wing as you noted.

Brian

John H. Campbell wrote:

whereas in gliders we're taught to bank at about 45 degrees or so.

I don't think so.

[multo snippo]

...how much steeper (and more stressful) are you planning to go
if your path is going past the line of the runway?

I guess I'd use as much bank as I need, whether 60 or 90, and whatever airspeed
and wing loading it takes to do the job, since I don't expect to be able to make
a go around. How about you? If I don't like the situation, I'll simply avoid
repeating it. Of course I have the advantage of having begun flying when the
laws of physics were considered to be useful rather than something of which to
be unduly terrified.

When the FAA again change the PTS, this time to something like a steep turn = 35
degrees, where will we be? Sixty degrees is a steep turn: 45 degrees is merely
an inappropriate pattern planning parameter. I generally fly my patterns fairly
close-in at around 20 to 25 degrees of bank. I mean, really, it's a glider after
all, not an F-105. On the other hand, if bank angle equals stress, perhaps we
should be advocating something other than flying gliders for more folks.

And Michael's following post:

...the quality of power instruction is, on the whole,
dramatically worse than the quality of glider instruction.
The majority of power instructors...teach their students
(wide, shallow bank patterns) because they don't know
anything else.

hits the nail on the head. Today's CFI-ASEL must teach wide shallow bank
patterns because that's what everyone uses, and to fly a proper pattern has
become nearly impossible when their are other aircraft in the pattern ahead, and
of course the ones behind won't know where to look for you and seem unaware of
the many possibilities.

Now if it would just stop raining, I could go out and soar instead of taking my
frustration out on good ol' John H., who is, after all, just doing what he
thinks is right.



Jack

If you can't pull off power, abeam the numbers, between 500 ft and 1000 ft
above the airport and make a landing
without adding or using power, you ought not to be flying light aircraft.
(Single engine 5000#)

Allan

"
The power-off pattern, where you bring the power to idle at about
800-1000 ft AGL and abeam the touchdown point and continue to a
landing, was once the normal pattern in general aviation for all light
trainers. Of course in such a pattern your turns will be 30-45
degrees of bank, depending on wind and how many mistakes you make.
The trainers have not changed; in fact we're mostly flying the same
ones. However, today's instructors see this as an emergency
procedure, not a normal one, because it pushes their skill level.

Michael

"Michael" wrote in message
om...
illspam (Jim Vincent) wrote

Mainly because the quality of power instruction is, on the whole,
dramatically worse than the quality of glider instruction. The
majority of power instructors are low time, inexperienced pilots who
have completed a training program that takes them from zero time to
instructor (single, multi, and instrument) in less than 300 hours.
They have been taught to fly wide, power-on patterns with stabilized
power-on approaches because this is what they will be doing in the
airlines (their eventual goal) and that's what they teach their
students because they don't know anything else.

Actually there are many reasons, some of them may be found in the SEL PTS.
Another is that airports with lots of light aircraft training end up with huge
"follow the leader" patterns.

Steep turns, especially at low speed, simply scare them. Therefore,
many of them tell students not to exceed 30 degrees of bank in the
pattern.

After several years of soaring, I recently decided to transition to power.
I have had that poor guy squirming in his seat and grabbing for the controls
more than once doing things that I considered perfectly normal, including tight
turns in the pattern.

The power-off pattern, where you bring the power to idle at about
800-1000 ft AGL and abeam the touchdown point and continue to a
landing, was once the normal pattern in general aviation for all light
trainers. Of course in such a pattern your turns will be 30-45
degrees of bank, depending on wind and how many mistakes you make.
The trainers have not changed; in fact we're mostly flying the same
ones. However, today's instructors see this as an emergency
procedure, not a normal one, because it pushes their skill level.


Come to think of it, the FAA has changed landings since our trainers were
designed. Vaguely 20 years ago, there was a sea change in the way landing
technique was taught because someone in the FAA decided that normal landings
would be accomplished with full flaps. The normal technique that is taught
these days (at least in a Cezzna) is the first notch on downwind, second notch
on base and full flaps on final. This adds so much drag that you either do a
high (and or tight) pattern or you must drag the thing around the pattern with
power. Guess which one they usually teach?


Vaughn



Michael

"John H. Campbell" wrote in message
...
whereas in gliders we're taught to bank at about 45 degrees or so.

I don't think so. A "medium" turn of 30 deg. works well (gliders are
typically most roll stable near this value), is first introduced, best
rehearsed, most common (it's the famous optimum bank for "standard"
thermals), easiest to perform (Laws of Learning REPEIR, Levels of Learning
RUAC...) and gives the option to go both to a "shallow" bank of 15 deg. or a
"steep" bank of 45 deg. to adjust turn radius in progress if necessary
(maintaining good coordination and speed control) without going (at low
altitudes no less) near the parachute-wearing limit of 60 deg. or the
"abrupt..." condition of aerobatic flight. The FAA PTS does not recommend
any particular bank angle for the Landing Task, but it does define a Steep
turn Task in the Performance Maneuver Area of Operation as 45 +/-5 deg. If
that's your starting value for an ordinary turn in the pattern, how much
steeper (and more stressful) are you planning to go if your path is going
past the line of the runway?

Thanks for this, I was starting to think I had been taught (and been
teaching) wrong.

Vaughn

Tony,
Me too!
Cheers!
"Tony Verhulst" wrote in message
...

...instructor (single, multi, and instrument) in less than 300 hours.
They have been taught to fly wide, power-on patterns with stabilized
power-on approaches because this is what they will be doing in the
airlines (their eventual goal) and that's what they teach their
students because they don't know anything else.

No kidding! I freaked one out once during a BFR by slipping a Skylane on
short final.

Tony V

In article , Tom Seim
writes
(Jim Vincent) wrote in message news:20040610165940.0224
...
In power, they're taught to fly patterns with very little bank angle, whereas
in gliders we're taught to bank at about 45 degrees or so. I well understand
the rationale for banking steeply in gliders, but why are power pilots taught
to do shallow turns?

The reason is, actually, pretty simple: power planes have god-awfull
visibility; if you bank too steeply you lose visual contact with a key
part of the pattern. This is something to keep in mind while flying in
the vacinity of power planes: if you can't see the cockpit, they can't
see you. In general, the best policy is to assume that they can't see
you and to act accordingly.

Tom Seim
Richland, WA

Not ALL power planes. Our club has 2 Robin D400 Avions for tugs and you
get a very good view out of them. The same goes for the Rallaye we used
to have.

I hesitate to say this, but maybe its just US aircraft?

--
Mike Lindsay