Glider vs. Power Pattern Bank Angle?

On 11 Jun 2004 05:26:34 GMT, illspam (Jim Vincent)
wrote:

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.

Tom, that makes sense to me for a high wing plane, but not for a low wing
plane. My friend had been taught never to bank too much in the pattern because
of the stall risk, I think. Yet us glider guiders are taught exactly the
opposite. Maybe since we fly the pattern so much closer to stall speed?


Jim Vincent
CFIG
N483SZ


I think many instructors don't like to contemplate a student pilot in
a low, slow, steeply banked turn in an aircraft with low aspect
ratios - such as most simple, powered aircraft. Low aspect ratio
means relatively high drag, thus relatively greater airspeed decay, at
a given AOA, including the relatively high AOA likely in slow, steep
turns.

The argument I've heard for the safety of steeper bank angles is
that the pilot is less likely to make the anxiety-forced error of
thinking the aircraft can be hurried around its turn by the liberal
application of pro-turn rudder: a skidded turn which produces it own
pitch and bank effects that can lead to a stall/spin.

Gliders, with their higher aspect ratio wings, suffer less drag, thus
less airspeed loss, a a given AOA.

illspam (Jim Vincent) wrote in message ...
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.

Tom, that makes sense to me for a high wing plane, but not for a low wing
plane. My friend had been taught never to bank too much in the pattern because
of the stall risk, I think. Yet us glider guiders are taught exactly the
opposite. Maybe since we fly the pattern so much closer to stall speed?


Jim Vincent
CFIG
N483SZ
illspam

I never bank *too much* in airplanes. In the pattern I use at least 30
deg, more for a high wing with a green house because that gives a good
view into the turn.

The view into the turn varies greatly for high wing airplanes. In a
182 leaning forward gives tolerable vizibility. In an Aeronca Chief
you can't see into the turn at all. That's why competent pilots will
raise the wing before starting the turn.

I don't think I flew any power plane with the view into the turn as
bad as from the 2-33 back seat!

I don't believe visibility is the reason some airplane pilots use
shallow banks in the pattern. I'm also not convinced that gliders fly
closer to stall speed in the pattern. I think it's just that some
airplane pilots were taught by instructors that didn't know any
better.

Andy

The PTS for the SEL rating requires the demonstration of steep turns,
and this maneuver is flown on virtually every check ride. I believe
that the main reason for "gentle" turns is a cultural and training
issue. Power training almost always considers the passenger in the
aircraft--something which is normally not a major issue in soaring.

Frankly, most true passengers are not comfortable in bank angles
greater than 30 degrees. A second MAJOR issue is the continuing
training toward the instrument rating. In actual instrument
conditions turns are normally accomplished at "standard" rate--a
gentle bank. This provides less chance for the pilot to loose control
while flying only with reference to instruments.

An often heard comment from the CFI during the training of a
commercial student is that when he gets his first commercial job his
performance will be judged by the smoothness of his landings
(regardless of winds, etc) and not spilling the president's drink in
the back.

Just some thoughts--

Skip Guimond

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

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?

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

"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

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

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