Are 'Single 180 Turn From Downwind to Final' and 'Stall-spin on Turnfrom Base to Final' mutually exclusive?

At 23:43 02 August 2016, wrote:
Can we agree that stalling is directly related to angle of attack and
secondarily related to airspeed?

Yes it is. The trigger for a departure is often the application of the
controls to change the attitude of the glider. Given one of the first
lessons we learn is the effectiveness of the controls in relation to
airspeed, the slower we are the more control needed.
In a constant banked turn the control movements tend to be much
reduced, the application of aileron in particular, with the consequent
changing of angle of attack at the tips of each wing, is much less.
The control required to increase or reduce bank in a turn is far less
that that required to go from level flight to banked turn. So is this a
factor? Certainly it should be that the increase in angle of attack at the

tip of the "upgoing" wing should be much less.
Like everything else in flying, if you do it right there is no problem.
When it is going wrong the application of control to put it right is quite

frequently our undoing.
To complete a 180 deg final turn requires one turn entry and one exit.
A "square circuit" requires two. In theory 50% less opportunity for
screwing it up.

Why is it always the guys who are wound to tight, the ones that accuse others of being wound too tight? (Generally doing so with the excessive use of capitals).

:O

Originally Posted by BobW

On 8/2/2016 10:58 AM, wrote:
All you expert pilots are I'm sure fully capable of flying in such a manner
as to back up your arguments and I'm sure that you are very safe due to
your refined skills. But, is your particular point really relevant to the
overall safest best practice that the sport as a whole should be teaching
and modeling? Are you always in peak form at the end of an epic XC? Are
all of your friends in soaring as reliably skilled as you?

I said it before but I'll say it again:

The majority of gliders are more stall and spin resistant at medium to
steeper banks than at shallower bank angles. (This is aerodynamically
different than most airplanes). A continuous 30 degree bank from downwind
to final exposes a pilot to a longer period of stall/spin-at-low-altitude
risk than two brief periods of stall/spin resistant steeper banked turns.
(Or 3 turns in the clipped base pattern).

Since this thread is a "natural" for topical drift, here's additional "best
pattern practices" food for thought...

While playing in this millennium's NTSB glider-fatality database this past
winter, the question floating into mental view - when considering the (very
many) landing-pattern-related departures from controlled flight fatalities -
was, "Why did Joe Deceased Pilot NOT fly "a normal pattern?"

The (closely related?) question, "Why didn't Joe Deceased Pilot fly the BEST
PRACTICES pattern?" never occurred to me, since it seemed so obvious that loss
of aerodynamic control almost exclusively occurred during "grossly
non-standard" ("drunken sailor?") patterns as distinct from "seriously botched
standard patterns." Some might think the questions a distinction without a
difference, but not to my mind.

IOW, those U.S. glider pilots killing themselves in landing patterns generally
do so from patterns not REMOTELY appearing to be an implementation of a "best
practices" pattern. Makes a person think, it does...

Bob W.

Bob,

First, I will caveat and say I am far from an expert pilot... That said, your comments are very true and obviously directly related to what are seen in accident reports. But as you mention, many accidents stem from poor patterns, which stem from denial of the need to give up trying to save something and accept a land out sooner and set up accordingly--that include room for a pattern and not having to try to scrape in at max L/D to get there. If you do not get low and slow, there is less tendency to pull back on the stick or push in rudder. Those two factors account for the majority of bad incidents. If people accepted this and at least flew in control and coordinated into crap landing areas they'd have better personal results, glider damage? maybe not so much, but that's not what's important.

To note, in flying my curved final turn, I'm not much of a rudder user. My fighter background makes me pre-disposed to inadequate rudder, and very disclosed to just banking it up if I need to turn harder. I was once told (after an early botched, late turn to final in a square pattern) that 60 degrees of bank wasn't usually used in the pattern.... I didn't want to overshoot, but I think the instructor would have preferred the overshoot to the bigger bank. Oh well...

But I understand most glider pilots do not have the same background, and can input rudder too much in continuous turns like we are talking about, therefore by nature they can be insidious. Given an error too far to the inside means a harder turn is necessary to get around, what does a different experienced person do? Rudder or bank? Or do they accept an overshoot and correct? From what I've seen, from what I've read, from your statements I'm guessing the safer courses of banking more or just accepting an overshoot are the least likely. Cutting a tight/shorter square pattern into a continuous turn or a shorter base leg is an easier correction to teach.

By discussion, I agree with the instructors that a continuous turn pattern for glider only or GA only pilots is not safer, and a square pattern provides more flexibility in correcting. I have had students who do say it is easier for them to see the turn around and to hit the cone on final out of this continuous turn than the square pattern (despite what some here say), and I feel the same. That doesn't make it less risky for low timers though. That must be understood.

But maybe if some were also taught a continuous curved pattern, using bank to turn harder if needed, might sometimes help some of these idiot patterns that are left too late, and when these people try to set up a pattern they are used to after waiting too long they are too low for it and get low and slow. If they set up closer and tried a continuous turn, keeping constant nose position, speed and bank, they might have fared better. Hard to say, but it could be a useful skill in a pinch, and maybe not left to the pinch to learn how to do if necessary.

But I do them because they are more fun, make it easier for me, and again, are something I always try to be perfect at, no matter how impossible that may be. But it's something in my tool bag. Oh, but my last land out? Big Square pattern. Just what I opted for.... Read into it what you want.

"Seems to me that if you are in danger of spinning from a shallow turn in the landing pattern, you are going much too slow."

Exactly. Or, if you are going much too slow you are in danger from spinning from a shallow turn in the landing pattern.

If you are going much too slow you are in less danger from spinning from a medium/steeper turn in the landing pattern because at low speed most gliders run out of up elevator authority before reaching critical angle of attack.

"Seems to me that if you are in danger of spinning from a shallow turn in the landing pattern, you are going much too slow."

Exactly. Or, if you are going much too slow you are in danger from spinning from a shallow turn in the landing pattern.

If you are going much too slow you are in less danger from spinning from a medium/steeper turn in the landing pattern because at low speed most gliders run out of up elevator authority before reaching critical angle of attack.

Just repeating this nonsense doesn't make it become true...

How do you teach your students to fly the approach in a glider?

How do you teach your students to fly the approach in a glider?

On Wednesday, August 3, 2016 at 12:12:40 PM UTC-4, wrote:
How do you teach your students to fly the approach in a glider?

To have more than one tool in the toolbox.

best,
Evan

On Wednesday, August 3, 2016 at 7:13:28 AM UTC-7, wrote:
"Seems to me that if you are in danger of spinning from a shallow turn in the landing pattern, you are going much too slow."

Exactly. Or, if you are going much too slow you are in danger from spinning from a shallow turn in the landing pattern.

If you are going much too slow you are in less danger from spinning from a medium/steeper turn in the landing pattern because at low speed most gliders run out of up elevator authority before reaching critical angle of attack.


If so, you have another problem -- the steep turn likely puts you below the speed at which the wings are creating enough lift to keep you in the air. At altitude, the nose will fall and you will pick up speed. Close to the ground, you may impact the terrain.