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

On Monday, August 1, 2016 at 5:10:18 PM UTC-7, Dan Marotta wrote:
First off, I DIDN'T disparage anybody, but you certainly are. You have NO IDEA what my "sphere of experience" is, or my experience in general.
To me, telling me that the way I fly is not safe is disparaging to
me.Â* True, I don't know your experience, so why don't you tell me?Â*
I've flown single, twin, and triple engined jets, single and twin
recips, and twin turboprop beginning 43 years ago.Â* I've flown
gliders for 30 years.Â* I've never damaged an aircraft in all that
time including 5 dead stick landings due to engine failures.Â* I've
flown 66 different types of aircraft.Â* I think that qualifies me to
decide which traffic pattern is best for me and I hope you'll note
that I've never told anyone the descending 180 turn to final is
best, only best for me.Â* If you've flown more years, hours, or
types, I respect that, but I don't think that makes my opinion less
valid or yours more.Â* I get stirred up when folks tell me that their
way is the safest (or best or only) way.



This translates to up to 220 ft/sec (a 180 deg turn takes 10-20 sec and complicates the design point on when to start the turn). If you hit unexpected sinking air during this turn you could be in a real pickle!
Â*



Maybe I misunderstood you, but didn't you make reference to 220 feet
per second or 130 kts ground speed?Â* I'd need a 60 kt tail wind on
downwind to achieve that kind of ground speed.Â* If you really had a
60 kt tail wind on down wind and flew a standard pattern, I'll wager
you would not have made it back to the runway.



When I flew an actual pattern with a wind 45 degrees to my right on
downwind and the GPS indicating 32 kts, I crabbed away from the
runway and spaced further, too.Â* How much?Â* Enough to fly a parallel
ground track.Â* Did I fly past the end of the runway before beginning
my 180 deg descending turn to final?Â* Heck no!Â* I started the turn
at mid field since that was the location where I wanted to stop to
clear the runway.Â* My wife, listening to AWOS, told me afterwards
that the wind was gusting to 50 kts!



I get a sense from your description that you profess flying a ground
track.Â* If I'm wrong in that, I apologize.Â* But in the above
described case a standard ground track would have resulted in me
bouncing off the side of the bluff upon which the airport is
located.Â* Simply stating that "square is safer" is, to be blunt, a
crock.



I DIDN'T say that your ground speed increases during your downwind turn. The point was you are covering a lot of ground fast and can end up further away from the runway than you expect.



Not me.Â* I'm in control of my aircraft and won't ever end up further
away than I expect unless there's some reason to widen my pattern.Â*
And I never said "downwind turn", what I said was "in turning
flight" which is exactly what the descending turn to final is.



And I said you could lose sight of the runway if you
flew a long downwind.Â* I begin my turn from downwind at or just
slightly beyond the threshold.Â* I said "you" could lose sight, not
"I" could lose sight.



You are trying to convince others of the superiority of your technique and I am offering the opposite side of the discussion. You need to calm down and discuss things rationally.


Go back and see what I've said.Â* I'm not trying to convince you or
anyone else that my way is better, though that's what the US Air
Force taught me and I think they know a bit about flying.Â* I've only
argued that all of contentions that my way is unsafe are hogwash.Â*
What works for me works for me.Â* Fly any way you want but please
quit telling me that what I do is "unsafe".Â* PS - I thought I was
being rational but apparently not, in your opinion.




On 8/1/2016 1:42 PM, 2G wrote:



First off, I DIDN'T disparage anybody, but you certainly are. You have NO IDEA what my "sphere of experience" is, or my experience in general.

My original contention stands: a square pattern is far safer than a button hook pattern.

I DIDN'T say that your ground speed increases during your downwind turn. The point was you are covering a lot of ground fast and can end up further away from the runway than you expect.

You agreed that you CAN lose sight of the runway; not losing sight requires a tight "carrier landing" turn which precludes a stabilized final. This is okay if the situation dictates, low altitude or an expedited landing for traffic, but is generally less safe than a square pattern.

You are trying to convince others of the superiority of your technique and I am offering the opposite side of the discussion. You need to calm down and discuss things rationally.

Tom




--

Dan, 5J

Hey Dan, you're strung WAY TOO TIGHT!

1. I NEVER said what you are doing IS NOT safe! YOU said that! In fact, I listed three situations where such a pattern would be not just appropriate, but preferred. What I said is that in all other situations a square (rectangular, if you prefer) pattern would be safer.

2. I am NOT going to get into a ****ing contest with you about who has the most experience; leave it be that I have PLENTY of glider experience. You can win that contest with the heavy iron experience, for what that matters.

3. I explained this before, but let's review:
a. 80 kt IAS @ 10 kft density altitude = 100 kt TAS
b. 100 kt TAS + 10 kt tail wind = 110 kt ground speed
c. 100 kt TAS + 30 kt tail wind = 130 kt ground speed

3. I don't see how you can judge wind speed and direction in a descending turn; flying a stabilized base leg gives a far better feel because you can visually see your crab angle. Same thing goes for the final approach.

4. It sounds like, but you never said, you descending turn is quite wide. Perhaps not that dissimilar to a square pattern with the two turns merged into one.

5. It seems like the CFIGs here agree with me.

6. You can fly whatever pattern you feel comfortable with, as far as I am concerned - you ARE NOT my target audience.

Tom

Sorry I don't know your name, 2G, nor do I know where you fly, and I'm
not trying to get into a ****ing contest. But let me offer you this:
Should you ever come to Moriarty or I come to wherever you are, let's
fly my Stemme together and demonstrate our patterns to each other. Then
we can laugh about it over a beer. Keyboards and time delays do make
for too much acrimony!

On 8/1/2016 7:07 PM, 2G wrote:
3. I don't see how you can judge wind speed and direction in a descending turn; flying a stabilized base leg gives a far better feel because you can visually see your crab angle. Same thing goes for the final approach.

I'll only reply to the above statement hopefully to explain but it's so
much easier to demonstrate. You can judge wind velocity during a turn
by your drift across the ground at low altitude. Then small corrections
can be made to fly the necessary ground track to arrive at the desired
location. Check it out next time you're thermalling down low.


--
Dan, 5J

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).

Turning flight presents a more dynamic visual picture then straight flight. Most normally equipped humans are better at assessing and reacting to the changing energy state of the glider (relative to landing area & speed) as well as detecting conflicting traffic and other hazards during wings level straight flight than during turning flight. This may be due to the less dynamic visual presentation in straight flight. This is especially true while under stress.

Le mardi 2 août 2016 18:58:43 UTC+2, a écritÂ*:

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).

And I ask you again: Would you please elaborate on this?

I've flown about 40 gliders, and voluntarily spun most of them. To my experience, your statement is nonsense.

At higher G loading as in steep turns many if not most gliders run out of elevator authority making them difficult if not nearly impossible to stall. Airplanes on the other hand have the propeller wash influencing elevator authority.

Le mardi 2 août 2016 22:07:26 UTC+2, a écritÂ*:
At higher G loading as in steep turns many if not most gliders run out of elevator authority making them difficult if not nearly impossible to stall.. Airplanes on the other hand have the propeller wash influencing elevator authority.

If your talking bank angles beyond 60 degrees, maybe. Anything below - absolutely not. That is, if you respect max mass in the seat.
Actually, if you stall a 25+ m ship at 60 deg bank, spin entry is much more violent than at 30 deg bank, and stopping the spin takes significantly more time. I've done that, and I won't do it again.

So, relating to patterns where you probably don't do more than 45 degree banks, your statement is senseless.

I haven't flown any 25 m gliders. I've flown about 35 types, a lot of trainers... The vast majority of them are much easier to stall and spin from shallow bank angles then from medium and steep bank angles. If I am alone in this perception that's news to me.

Not commenting on whether this is true or not but only to inform of at least one place where glider pilots are taught that steeper turns are less likely to result in a stall. From Glider Basics - From First Flight to Solo, by Tom Knauff:

"It is very important for you to understand it is extremely difficult, if not impossible, to stall a glider in turns of 30 degrees angle of bank or more." You can find the entire discussion on page 79 of his book, as well as in multiple other locations in the text.

Robert

On Tuesday, August 2, 2016 at 3:22:20 PM UTC-5, Tango Whisky wrote:
Le mardi 2 août 2016 22:07:26 UTC+2, a écritÂ*:
At higher G loading as in steep turns many if not most gliders run out of elevator authority making them difficult if not nearly impossible to stall. Airplanes on the other hand have the propeller wash influencing elevator authority.

If your talking bank angles beyond 60 degrees, maybe. Anything below - absolutely not. That is, if you respect max mass in the seat.
Actually, if you stall a 25+ m ship at 60 deg bank, spin entry is much more violent than at 30 deg bank, and stopping the spin takes significantly more time. I've done that, and I won't do it again.

So, relating to patterns where you probably don't do more than 45 degree banks, your statement is senseless.

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.

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.