Polar with spoilers extended?

I have used the high speed parasitic drag approach, and others.

First point is - no-one here has mentioned that the appropriate action depends
on the wind speed and direction.

In all cases drag increases at the square of velocity.
If you have a really low drag glider that is optimised for high speed you might
not get that high a return.
In a low performance ship the results are dramatic.

Consider being way too high on final approach in a low wing loading wood and
fabric trainer. If you are in still air, or have a tail wind then diving will
work best. Maximum drag, get close to the ground, bleed speed off.
If you have a strong headwind you can slow down and increase your angle of
decent, not rate. This is the inverse calculation of working our McCready speed
for best XC distance. Here you want to reduce the distance by flying too slowly.
One hint - you will be descending through wind gradient so leave a height +
speed reserve to compensate close to the ground.

Another technique is - if you see you are too high turning onto final, why
continue the turn. Extend the base leg a bit, make a steep 90 degree turn back
and line up. It is a sort of S turn, but more effective in that you start from
90 degrees to the landing point.

I know at least one pilot who has serious injuries from making an S turn and
losing it. So any of the approaches carries risk. We generally teach side
slipping as the preferred method, and with 6000 feet of runway - land long
rather than spin in trying to nail the threshold. Landing in a field is a
different matter.

I must agree the 360 is a bad idea. Not saying you should never do it - I did it
once to avoid conflicting traffic - but it is not advisable/comfortable to lose
sight of the runway low down. Use the appropriate one for the circumstances.

wrote:
On Oct 22, 7:57 am, wrote:
On Oct 21, 11:13 am, Tim Taylor wrote:
[snip]
If you are THAT much too high, wouldn't it also be prudent to consider
a large 360? It may not be pretty, but let's face it, if you have
turned final and just THEN realized you're way too high, you've
already lost all your style points.

Was this a serious comment? How many more people have to die to prove
you should not be suggesting turning away from the runway? A pilot was
killed in the Sierras in the last few years doing exactly this and we
had at least another major accident this year in the Sierras this year
with the same thing. It is on of the precursors to stall-spin
accidents, nasty scenarios like if unexpected lift cause the glider to
be high, the turn takes the glider out of lift, now you are going down
fast and pointing the wrong way. And low and the ground is coming up
at you, maybe I'll pull back more, push that foot to make the nose go
round, ugh, oh f!@#... Use S-turns, parasitic drag approaches, slips
etc. but don't turn away from the runway.

---

As for the high speed/paracitic drag approach Cindy Brinkner talked
about this at an SSA convention a few years ago. Maybe she has slides
available etc. I was suprised by the whispering amongst some people
in the audience about "ohh this is bad". I see it as a very useful
tool to have in your toolkit. I think Cindy's points were don't try it
by yourself - go take a ride with an knowledgeable instructor and that
in the hands of less experienced piltos in the right gliders this may
be a safer techqunique than slipping - I've seen pilots who have *no*
clue how to really slip to loose height, far too timid, nose just a
little off center - I have no idea if they were taught better and have
just forgotten or what.

Like Marc says the Duo tends to hold energy and makes this somewhat
less useful (but it still works, you do come down faster), but slips
work great in a Duo as compensation for not overly effective spoilers.
I was all set to demonstrate a parasitic drag approach in a Duo today
but the instructor doing the check ride thought a rope break would be
better :-(

Things are not black and white, I'd hope good pilots want to try out
different techniques, see what works best in different gliders and
situations and have the benefit of different tools at their disposal.

Darryl

Others have suggested
increasing speed to increase drag. I am not a big fan of this
technique because I feel it minimizes options for the pilot and is
susceptible to pilot error that can end up in over shooting the LZ.

I didn't think so either until Marty Eiler at Cal City demonstrated it
for me as part of a BFR. Practiced, and properly done, it can produce
an unbelievably steep angle from decision point to stopping point. Yes
you have to point the nose at the ground and look temporarily like
you'll undershoot. Definitely not for beginners, but not a maneuver to
be dismissed either.

A suggestion: I bought a copy of the condor flight simulator a while
ago, in part to explore on the ground how things like this work out.
It does let you practice and explore limits of glider abilities. You
can find out, for example, exactly how much altitude a 360 will take
in various configurations, or how much altitude you really need for a
180 back to the airport.

John Cochrane

On Oct 22, 11:30 am, BB wrote:
Others have suggested
increasing speed to increase drag. I am not a big fan of this
technique because I feel it minimizes options for the pilot and is
susceptible to pilot error that can end up in over shooting the LZ.

I didn't think so either until Marty Eiler at Cal City demonstrated it
for me as part of a BFR. Practiced, and properly done, it can produce
an unbelievably steep angle from decision point to stopping point. Yes
you have to point the nose at the ground and look temporarily like
you'll undershoot. Definitely not for beginners, but not a maneuver to
be dismissed either.

A suggestion: I bought a copy of the condor flight simulator a while
ago, in part to explore on the ground how things like this work out.
It does let you practice and explore limits of glider abilities. You
can find out, for example, exactly how much altitude a 360 will take
in various configurations, or how much altitude you really need for a
180 back to the airport.

John Cochrane

Doing these tests in the actual glider (at high altitude) with a data
logger will produce reliable numbers. The simulator might or might
not reproduce the performance accurately enough.

Todd Smith
3S

BB wrote:
Others have suggested
increasing speed to increase drag. I am not a big fan of this
technique because I feel it minimizes options for the pilot and is
susceptible to pilot error that can end up in over shooting the LZ.

I didn't think so either until Marty Eiler at Cal City demonstrated it
for me as part of a BFR. Practiced, and properly done, it can produce
an unbelievably steep angle from decision point to stopping point. Yes
you have to point the nose at the ground and look temporarily like
you'll undershoot. Definitely not for beginners, but not a maneuver to
be dismissed either.

I find it a very useful technique if I am high enough on final to use
it. Generally, I use it shortly after turning final as I realize I am
too high, even with full spoiler. That's when I have 500' agl or so,
which is plenty. Going from 50 knots to 70 knots (watch the flap setting
speed) doubles the rate of energy loss. When I slow down to 50 knots
again (still at full spoiler), my new "aim point" is much closer, and I
can reduce the spoilers to (ideally) about half.

If I'm "low", say less than 200', when I decide I'm too high, slipping
is my choice. I've never used S turns: if I'm high enough to make turns
on final, it's easier and safer to dive off the speed.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

On Oct 22, 5:58 pm, Eric Greenwell wrote:
I find it a very useful technique if I am high enough on final to use
it. Generally, I use it shortly after turning final as I realize I am
too high, even with full spoiler. That's when I have 500' agl or so,
which is plenty. Going from 50 knots to 70 knots (watch the flap setting
speed) doubles the rate of energy loss. When I slow down to 50 knots
again (still at full spoiler), my new "aim point" is much closer, and I
can reduce the spoilers to (ideally) about half.

All this is way outside my experience, and I'm not going to attempt it
myself (though I might nobble an instructor experienced at it).
However I still have a question: do you dive and then return to normal
approach speed before rounding out, or round out at the much faster
speed? If the latter, does not the extra float in ground effect negate
the losses from extra drag in the dive, especially with a slippery
glass ship versus a draggy wood and fabric glider (such as one a pilot
might train in)?


Dan

BB wrote:
Others have suggested
increasing speed to increase drag. I am not a big fan of this
technique because I feel it minimizes options for the pilot and is
susceptible to pilot error that can end up in over shooting the LZ.

I didn't think so either until Marty Eiler at Cal City demonstrated it
for me as part of a BFR. Practiced, and properly done, it can produce
an unbelievably steep angle from decision point to stopping point. Yes
you have to point the nose at the ground and look temporarily like
you'll undershoot. Definitely not for beginners, but not a maneuver to
be dismissed either.


I had this taught to me as part of my UK Basic Instructor renewal
course/checks. It works well in a glider with good airbrakes, but not in
something like my Open Cirrus (unless, perhaps, it's a long, long
approach so that there's time to drop below glide path with full brake
and normal approach speed, then bleed off the speed and come back into
the approach funnel at the proper speed).

It's one for the experienced (and properly taught) because you need to
know what's going to happen after you round out. In, say, a Puchacz, the
brakes are so good that you get only a comparatively small increase in
float. In my Cirrus, 10kt extra with full airbarke will far more than
double the float at a height where there is nothing you can do about it
except hang on. Libelles are known to be similar, and from a previous
poster the Duo Discus as well. Fortunately, those who fly gliders with
"weak" airbrakes soon learn about approach speed control ....

Tim Taylor wrote:

[....]

I have used the technique of slowing down to minimize forward speed,
increase sink and decrease glide angle. Others have suggested
increasing speed to increase drag. I am not a big fan of this
technique because I feel it minimizes options for the pilot and is
susceptible to pilot error that can end up in over shooting the LZ.
Last years article in soaring I believe confirms my feeling that this
is a technique that should not be held up as one of the primary
techniques that should be used. I am working on developing models to
asses each in terms of effectiveness, time required, safety and
options left to the pilot.


Increasing speed has its uses, and it has the distinct advantage of
being able to get out of rather more easily and safely than slowing
down, when you find you have over-done it. Of course there is the
concern that those who find themselves needing a lot of it may not be
the persons who'll know promptly when they've had enough, nor how best
to handle having too much--but there are ways to avoid being one of them.

The S-turns can be helpful when one has both the horizontal and
vertical space for them, if we arrange to be finished with them before
we are low, and ALWAYS watch our drift, as it changes with altitude and
airspeed changes--both IAS and GS--throughout the final approach. I
often see people failing to correct for drift as soon as they should,
which only leads to further complications.

I've found it useful to practice with increasing amounts of variation
from the basic final approach airspeed, both plus and minus, in order to
get to know what works with my glider in the relatively controlled
environment of my home field. This is at least a start in preparing for
the inevitable off-field or strange-field approach and landing, not to
mention the unheralded/unheeded arrival of geese, Cessnas, Boeings, or
skydivers in the pattern.

I can only advise any rated pilot to try each of those techniques
under benign conditions, working in small increments away from the
nominal speeds and configurations, changing one variable on each
approach. Pretty much what you learned to do in high-school science
labs. It may not be rocket science, but please do have a plan on every
approach--just as you do on every departure--to include touchdown and
stop points. And when you are on the ground make sure you know why the
plan worked, or why it did not--before you take the next step.

Thanks for the opportunity to harangue the assemblage. I'll try to
remember to impose some limits on this sort of thing next time, possibly.


Jack

High on Final, Summary

Thanks to all that have given input so far. My original intent was to
do some modeling before starting the discussion, but this is RAS and
it has a life of it's own.

So here is the issue. You are high on final and full spoilers are to
enough; what do you do?

List of options so far:

1. Slip
2. "S" turns
3. Dive until intercepting normal angle for spoilers
4. Dive until near the ground, then decelerate
5. Slow down until intercepting normal angle for spoilers
6. 360 degree turn

Unfortunately I still don't have good data for what happens to the
polar as speed increases with the spoilers open. Condor was a good
suggestion, and I am working to see if I can get meaningful data from
it.

John Cochrane brought the discussion back to the real point which is
what would you use in the real world? It is interesting but not that
useful to discuss how you do this at your home airport with 2500 to
9000 feet of runway and know precisely the field elevation. When your
aircraft and your own safety are on the line in a real off-field, what
are you going to do?

This is where I find teaching some of these other techniques
interesting, but possibly dangerous. The rule of primacy for learning
or as the Doobie Brothers album from the 70's title "What were once
vices are now habits" suggests we will do in an emergency what we have
practiced. Is someone really going to dive a glider to the ground and
pull out to land in a short off field landing? Is there really a need
to be on the ground 10 seconds faster than using some of the other
techniques? Maybe only if a severe thunderstorm is approaching and
you must be on the ground now. I think in general the high parasitic
drag technique being taught by some schools is a hyped method that may
give some less experienced pilots the idea this is a good technique to
use for off-field landings. I think it is time to get back to basics
and teach sound techniques that provide the best tools for pilots to
use day in and day out.

The dive until intercepting normal angle for spoilers has some merit,
but I still think should be used with caution. Why, because we train
to look at landings from a specific angle for a narrow range of
landing speeds. To dive at high speed leaves the aircraft with a much
greater kinetic energy that must still be lost someplace. Depending
on the ship type some may take much longer to dissipate this excess
and make it more difficult to precisely hit a touch down point. Often
the greater sink rate is held up as the reason for using this
technique. It is true that sink rate goes up with speed, but the
actual decent angle does not go up nearly as much. For my Ventus B at
45 knots descent rate is 122 ft/min while at 135 knots it is 894 ft/
min, but actual loss per nautical mile is 163 ft/ktm verses 397 ft/
ktm. The other thing we don't mention is the average pilot going to
handle the decision making process better at higher speeds and less
time? At stable speeds it takes about 11 seconds to lose 300 feet at
135 knots with the spoilers out verses 22 seconds at 45 knots. Do we
need that extra time to make proper judgment and fine adjustments to
hit a target for a tight off-field landing?

Ok, lets try a hypothetical (well maybe not, been there done that ;-)
off-field landing.

The situation: You are 70 miles from home over unfamiliar territory
(read not sure of exact elevation of the terrain below, your altimeter
is useless now). You have gone for a Cu over a dry lake bed and it
doesn't work. You have selected a landing site in the lake bed that
is about 350 feet long and 100 feet wide that looks safe to land.
There are tree stumps and other object in other parts of the lakebed.
There are no obstructions on the ends of the site so you can do a
normal approach. The winds are 15 to 20mph out of the south so you
are landing from the north to south. As you drop lower you make a
rectangular pattern over the site checking for any missed obstacles.
The downwind is fast with the tailwind, as you turn base you estimate
you are 400 feet. Your adrenaline is pumping as you prepare for a
fairly technical landing. You want to keep it close so that you don't
end up short back into the wind and you turn base a little too soon.
You are on short final about 350 feet, but about 100 feet over full
spoilers decent. What do you do?

Slip?
"S" turns?
Dive until intercepting normal angle for spoilers?
Dive until near the ground, and then decelerate?
Slow down until intercepting normal angle for spoilers?
360 degree turn?

In the real world nearly 15 years ago this was in a 1970 "A" model
Standard Cirrus. If you think the Duo will float try the Standard
Cirrus. What should we be teaching students? You are somewhere
between 11 and 30 seconds from being on the ground and that 100 extra
feet will take you past the whole safe landing area and into the tree
stumps.

Dive until intercepting normal angle for spoilers?

Maybe, but can you dive, lose the altitude, decelerate and get it on
the ground for a tail wheel first, full stall landing? I would give
this a 6 out of 10. This also shortens the time available to make
adjustments and requires rapid and precise decisions.

Dive until near the ground, and then decelerate?

My guess is your chances are slim that you can pull this off and get
the ship stopped. Especially, if you were flying my Std. Cirrus. My
rating is a 1 out of 10.

360 degree turn?

I never like to turn my back on a field. Low and with the winds a
good result is not likely. My rating is a 0 out of 10.

Slow down until intercepting normal angle for spoilers?

This technique is useful for very high approaches, but must be broken
off before 300 feet agl because you must have height to accelerate and
be able to recover from any inadvertent stalls. From about 1000 feet
to 500 feet this technique has the advantage of giving a higher decent
rate and giving the pilot more time to evaluate the situation, but the
pilot must be ready to respond to any sign of stall. My rating is a 0
out of 10 here.

"S" turns?

This might be useful. You are low, but may have time to extend the
your descent. Any turn at this point will require nearly at least 180
degrees of turning (45 away, 90 back and 45 back to final.) and up to
360 degrees with three changes in direction and roll. The advantage
is your speed stays constant and you can see the touchdown point the
whole time. A disadvantages is you are no longer lined up on the
target so your perception changes as you roll and move to the side.
My rating is a 7 out of 10 here.

Slip?

The forward slip can be very effective at bringing "most" ships down.
Check you flight manual of your aircraft and practice at altitude.
The old joke about you could always tell who the Std. Cirrus and
Libelle pilots were because they were slipping on final is true. But
we got very good at it. It would nearly double the sink rate and when
kicked out you were nearly at the correct speed. The Std. Cirrus if
flown even 5 knots too fast would float a long way before settling.
The nice thing about a slip is your speed and angles all stay the same
without speeding up the process. You can use your trained judgment to
say the angle looks about right here and kick out of the slip and
proceed with a normal landing. My rating is a 10 out of 10 here.


Summary
Each situation is different, but I think we should focus on teaching
techniques that are robust and give that average pilot the best
opportunity to have a good outcome in an off-field landing. I know of
very few off-field landings that start at 1000 feet at the end of down
wind. If I have found that much lift on downwind I have cycled the
gear and am climbing out, not landing. Any technique that requires
bleeding speed in ground effect should not be taught as anything other
than a curiosity and never considered for off-filed landings.

On Oct 24, 5:36 am, Tim Taylor wrote:
High on Final, Summary

Thanks to all that have given input so far. My original intent was to
do some modeling before starting the discussion, but this is RAS and
it has a life of it's own.

So here is the issue. You are high on final and full spoilers are to
enough; what do you do?

List of options so far:

1. Slip
2. "S" turns
3. Dive until intercepting normal angle for spoilers
4. Dive until near the ground, then decelerate
5. Slow down until intercepting normal angle for spoilers
6. 360 degree turn

Unfortunately I still don't have good data for what happens to the
polar as speed increases with the spoilers open. Condor was a good
suggestion, and I am working to see if I can get meaningful data from
it.

John Cochrane brought the discussion back to the real point which is
what would you use in the real world? It is interesting but not that
useful to discuss how you do this at your home airport with 2500 to
9000 feet of runway and know precisely the field elevation. When your
aircraft and your own safety are on the line in a real off-field, what
are you going to do?

This is where I find teaching some of these other techniques
interesting, but possibly dangerous. The rule of primacy for learning
or as the Doobie Brothers album from the 70's title "What were once
vices are now habits" suggests we will do in an emergency what we have
practiced. Is someone really going to dive a glider to the ground and
pull out to land in a short off field landing? Is there really a need
to be on the ground 10 seconds faster than using some of the other
techniques? Maybe only if a severe thunderstorm is approaching and
you must be on the ground now. I think in general the high parasitic
drag technique being taught by some schools is a hyped method that may
give some less experienced pilots the idea this is a good technique to
use for off-field landings. I think it is time to get back to basics
and teach sound techniques that provide the best tools for pilots to
use day in and day out.

The dive until intercepting normal angle for spoilers has some merit,
but I still think should be used with caution. Why, because we train
to look at landings from a specific angle for a narrow range of
landing speeds. To dive at high speed leaves the aircraft with a much
greater kinetic energy that must still be lost someplace. Depending
on the ship type some may take much longer to dissipate this excess
and make it more difficult to precisely hit a touch down point. Often
the greater sink rate is held up as the reason for using this
technique. It is true that sink rate goes up with speed, but the
actual decent angle does not go up nearly as much. For my Ventus B at
45 knots descent rate is 122 ft/min while at 135 knots it is 894 ft/
min, but actual loss per nautical mile is 163 ft/ktm verses 397 ft/
ktm. The other thing we don't mention is the average pilot going to
handle the decision making process better at higher speeds and less
time? At stable speeds it takes about 11 seconds to lose 300 feet at
135 knots with the spoilers out verses 22 seconds at 45 knots. Do we
need that extra time to make proper judgment and fine adjustments to
hit a target for a tight off-field landing?

Ok, lets try a hypothetical (well maybe not, been there done that ;-)
off-field landing.

The situation: You are 70 miles from home over unfamiliar territory
(read not sure of exact elevation of the terrain below, your altimeter
is useless now). You have gone for a Cu over a dry lake bed and it
doesn't work. You have selected a landing site in the lake bed that
is about 350 feet long and 100 feet wide that looks safe to land.
There are tree stumps and other object in other parts of the lakebed.
There are no obstructions on the ends of the site so you can do a
normal approach. The winds are 15 to 20mph out of the south so you
are landing from the north to south. As you drop lower you make a
rectangular pattern over the site checking for any missed obstacles.
The downwind is fast with the tailwind, as you turn base you estimate
you are 400 feet. Your adrenaline is pumping as you prepare for a
fairly technical landing. You want to keep it close so that you don't
end up short back into the wind and you turn base a little too soon.
You are on short final about 350 feet, but about 100 feet over full
spoilers decent. What do you do?

Slip?
"S" turns?
Dive until intercepting normal angle for spoilers?
Dive until near the ground, and then decelerate?
Slow down until intercepting normal angle for spoilers?
360 degree turn?

In the real world nearly 15 years ago this was in a 1970 "A" model
Standard Cirrus. If you think the Duo will float try the Standard
Cirrus. What should we be teaching students? You are somewhere
between 11 and 30 seconds from being on the ground and that 100 extra
feet will take you past the whole safe landing area and into the tree
stumps.

Dive until intercepting normal angle for spoilers?

Maybe, but can you dive, lose the altitude, decelerate and get it on
the ground for a tail wheel first, full stall landing? I would give
this a 6 out of 10. This also shortens the time available to make
adjustments and requires rapid and precise decisions.

Dive until near the ground, and then decelerate?

My guess is your chances are slim that you can pull this off and get
the ship stopped. Especially, if you were flying my Std. Cirrus. My
rating is a 1 out of 10.

360 degree turn?

I never like to turn my back on a field. Low and with the winds a
good result is not likely. My rating is a 0 out of 10.

Slow down until intercepting normal angle for spoilers?

This technique is useful for very high approaches, but must be broken
off before 300 feet agl because you must have height to accelerate and
be able to recover from any inadvertent stalls. From about 1000 feet
to 500 feet this technique has the advantage of giving a higher decent
rate and giving the pilot more time to evaluate the situation, but the
pilot must be ready to respond to any sign of stall. My rating is a 0
out of 10 here.

"S" turns?

This might be useful. You are low, but may have time to extend the
your descent. Any turn at this point will require nearly at least 180
degrees of turning (45 away, 90 back and 45 back to final.) and up to
360 degrees with three changes in direction and roll. The advantage
is your speed stays constant and you can see the touchdown point the
whole time. A disadvantages is you are no longer lined up on the
target so your perception changes as you roll and move to the side.
My rating is a 7 out of 10 here.

Slip?

The forward slip can be very effective at bringing "most" ships down.
Check you flight manual of your aircraft and practice at altitude.
The old joke about you could always tell who the Std. Cirrus and
Libelle pilots were because they were slipping on final is true. But
we got very good at it. It would nearly double the sink rate and when
kicked out you were nearly at the correct speed. The Std. Cirrus if
flown even 5 knots too fast would float a long way before settling.
The nice thing about a slip is your speed and angles all stay the same
without speeding up the process. You can use your trained judgment to
say the angle looks about right here and kick out of the slip and
proceed with a normal landing. My rating is a 10 out of 10 here.

Summary
Each situation is different, but I think we should focus on teaching
techniques that are robust and give that average pilot the best
opportunity to have a good outcome in an off-field landing. I know of
very few off-field landings that start at 1000 feet at the end of down
wind. If I have found that much lift on downwind I have cycled the
gear and am climbing out, not landing. Any technique that requires
bleeding speed in ground effect should not be taught as anything other
than a curiosity and never considered for off-filed landings.

Great summary Tim !

To further your point on training: One thing we need to do in
training is demonstrate the effect of flying the final too fast.
Back-to-back pattern flights with different final speeds and
the same aim point really help pilots internalize this.
Especially for transition pilots (Cirrus, 1-35 come to mind),
practicing this on an appropriately long runway brings
religion to pattern energy management like no amount
of briefing...

Be careful out there,
Best Regards, Dave "YO"

On Oct 24, 7:09 am, wrote:
Great summary Tim !

I agree.

A quick response to the above choices would be based on how much too
high I was. And Tim's list is pretty much in the correct order:

1. Slip
2. "S" turns
The first one likely being an overshoot of the turn to final, then a
120-180 back toward the runway, repeat if necessary, then line up on
the runway.

3. Dive until intercepting normal angle for spoilers
4. Dive until near the ground, then decelerate
Not sure if I like this one... I think #3 is the proper way to do
it. Though, if one is REALLY high, then the proper angle for 'normal'
final would be pretty close to the ground. I would be in this
situation if there are strong winds and chance of downbursts (been
there, done that). Turn final way high expecting the 40+ headwind to
be there (perhaps downburst since the storm is nearby), but instead
the wind quits! In my ASW-20B, I just did a full flap, full spoiler
slip with the nose way below the horizon, so it really was a diving
slip - remember I was WAAAY high. Ended up stopping at my intended
spot even though there was a slight 2-3 knot tailwind.

5. Slow down until intercepting normal angle for spoilers
Perhaps

6. 360 degree turn
Actually, I doubt one would be on final when this decision is made, so
perhaps a 270 degree turn from base to final. But only if the weather
is considered to be benign. I watched an ASW-22BL do this at a fairly
low altitude while going into a fairly short field on a relatively
calm day and it made sense. Due to the ship's low sink rate, the
pilot was able to drop perhaps 100' and also end up slightly farther
away from the touchdown spot.

-Tom