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

[son_of_flubber]

The 'Single 180 Turn From Downwind to Final' (aka 'military style pattern') and 'Stall-spin on Turn from Base to Final' are both well discussed as independent topics on RAS. But I've not seen anything about how these pieces fit together.

Having recently tried the 'Single 180 Turn...' and LIKED it, I'm wondering if there is any good reason why I should not fly this approach at an uncontrolled airport with mostly glider traffic. What about at a controlled airport with mostly GA power traffic?

And I'm wondering if anyone has ever stall-spinned from a 'Single 180 Turn...' pattern and whether there are subtle 'gotchas' associated with that pattern shape that I should know about.

What is the military's track record wrt 'Stall-spin in the pattern'? Does it happen just as often with the 'Single 180 Turn...'?

[tkn...@earthlink.net]

You need to try the inverted flight landing pattern. It gives a great view of the earth, making it easier to make some decisions.

Yep, there is a "best way" after you take everything into consideration.

Tom

[Giaco]

If you are talking about glider flying for the military, I don't believe West point has a club, Navy flies at a local SSA club, and the Air Force Academy Flies a standard right-hand pattern that is tower controlled and in Class D Airspace.

The Air Force's record prior to making it an enforced and strict program was not all that terrific, but since regimenting the program and beating airspeed control into student's heads, they may have one of the best safety records in the gliding world (incident per flights)...

Probably goes to show that you can fly whatever pattern you want as long ask you maintain a safe airspeed for your flight condition.

[markm...@gmail.com]

I don't normally weigh in on things like this because of the (many) passionate opinions about "proper" this or that, but last year when I was getting a check ride with a Designated FAA Examiner in the jet powered TsT-14 BonusJet glider(www.desertaerospace.com), I was chastised for doing a tight 180 to final. "Your head and eyes are focused on the threshold and touchdown point from downwind to final. This is an uncontrolled airport. If you had a guy without a radio on final, you will never see him. Do a square pattern with crisp a 90 degree turn from downwind to base, look over to the opposite direction to clear for traffic and make a crisp 90 to final."

Two flights later, that scenario happened while I was approaching to land in my Pegasus 101A. Looked right on my left downwind to base and saw a rather disturbing sight. I elected to take the adjacent taxiway to avoid being run over by a KingAir who had made a long straight-in final approach, happily announcing his intentions over the radio....but not on the airport frequency.

I mentioned it to him as he was getting gas. At first he growled about almost getting "cut off" in the pattern by some dumbass glider pilot, but his face went white when I asked him what frequency he was using. Turns out he was still on ABQ Center and not 122.90, the Moriarty frequency. Live and learn. I appreciate good advice, and my normal pattern for landing has some margin built in after that little incident.

[Bob Whelan]

On 7/27/2016 5:33 PM, son_of_flubber wrote:
> The 'Single 180 Turn From Downwind to Final' (aka 'military style pattern')
> and 'Stall-spin on Turn from Base to Final' are both well discussed as
> independent topics on RAS. But I've not seen anything about how these
> pieces fit together.

So how many glider pilots are in the room and how many opinions will they have
regarding your implicit question?! (Chortle.) As always, the devil is in the
details, and in my (experience-based) view there's no single "absolutely
right" answer. There are many very good reasons we're instructed to "fly
regulation glider patterns," but the accident record clearly shows that
attempting to do so is far from a panacea. If it's possible and it helps you,
then fine - do it. You'll likely have full approbation of the glider
community, instructors included. But never lose sight of what a landing
pattern is intended to do: help you make a safe landing, at the spot you've
selected.

Some years ago I flew an original-spanned HP-14 with the as-designed (see next
paragraph) ailerons from a busy, non-towered GA airport with 3 parallel
runways (Boulder, CO). Back then, the paved/lit one was "the power runway"
(legally available for glider use, of course). (An estimated) 100 feet
center-line-to-center-line to the north were two, unpaved "glider only"
runways. The northernmost one was the one from which 99.9% of all gliders
launched (trailers/tiedowns/assembly-area being immediately north of it), and
maybe 70% of the gliders and 50% of the towplanes landed. The center one
(rarely) launched and (variously) landed the remainder. Occasionally
non-towing taildraggers would use one or the other of "the glider runways."
The glider runways' landing percentages varied with traffic volume, landing on
the northernmost runway being the default, traffic permitting. When the sky
occasionally rained gliders, gliders would sometimes "land long," overflying
ships landed short, though this wasn't common. Point being, it was/is a *busy*
airport, and pilots were/are taught/expected to keep their heads on a swivel.
Shoot, we practiced their "situational awareness" long before it became a
catchphrase, as a means of NOT having to do anything "unusual" in the landing
pattern! (Google Earthing will show the northernmost runway is now paved. Last
time I looked, there was a glider in the pattern!)

A common mod to original-aileroned HP-14s was to convert the outer 3-feet of
each flap to ailerons, since as-designed, no one would characterize its roll
rate as "spritely." Evidently the increased roll rate was deemed more
worthwhile than the reduced (but still manly) flap-power....but I wouldn't know.

Boulder's published/recommended pattern procedure, is for gliders to fly a
rectangular pattern, crosswind entered at midfield, downwind/base/final inside
the power equivalents, left-hand to the east, right-hand to the west. It's not
uncommon to have a power plane or two buzzing along downwind for company,
though parallel takeoffs are "seriously discouraged"/prohibited and parallel
landings likewise discouraged. At some point in every landing pattern, of
course, the glider's spacing/timing options vanish, though some might find it
surprising how much flexibility gliders bring to the table, assuming good
"situational awareness."

The preceding verbosity can be shortened to: gliders must fly their patterns
inside the power plane pattern. It generally works well.

So - I'm landing a slow-rolling glider with relatively high stick forces in
roll (and light elevator forces), using a pattern distinctly constrained in
size. While it was possible to make 90-degree-turn-patterns in the HP-14 at
Boulder, it pretty much took both hands on the stick to do it and was
something of a distraction/PITB judging when to begin the turn to final. It
was considerably easier, both in stick forces and in
mentally/visually/continuously assessing the approach, to make the transition
from downwind to final a continuously/varying-as-necessary-banked turn. I felt
it was equally as safe as "a standard glider pattern" too, in
traffic-avoidance turns...I could still easily check the power final, for
example, and one can rationalize that banked gliders are easier to spot than
unbanked ones.
- - - - - -

> Having recently tried the 'Single 180 Turn...' and LIKED it, I'm wondering
> if there is any good reason why I should not fly this approach at an
> uncontrolled airport with mostly glider traffic. What about at a
> controlled airport with mostly GA power traffic?

There's a lot to be said favoring "When in Rome, do as the Romans," but YMMV.
I've no doubt others will share other (and I'll wager, strongly held!) views
on these questions.
- - - - - -

> And I'm wondering if anyone has ever stall-spinned from a 'Single 180
> Turn...' pattern and whether there are subtle 'gotchas' associated with
> that pattern shape that I should know about.

Having immense faith in human ability to screw up, I'll put real money on
people "departing from controlled flight" in *every* landing pattern known to
mankind! Personally, I think the circling-pattern gotchas not fundamentally
different from *any* pattern's "Gotchas!" Airspeed and coordination rule.
Presupposing those are as-desired, don't hit anything other than the spot for
which you're aiming. As for judging how you're doing relative to bad things to
hit in the landing pattern while in controlled flight, there's considerable
experience favoring certain pattern shapes...and less for others (due both to
less use, and as well to "It's just a bad idea!" for some [e.g.
straight-ins]). In my motherhood and apple-pie view, a pattern is no more and
no less than an unavoidable-vehicle/useful-aid to making safe landings.

I never discerned substantive differences/difficulties between using
rectangular patterns and circling patterns, but YMMV.

When I sold the HP and began flying a Zuni, I transitioned back to rectangular
patterns, following the "When in Rome..." philosophy. The (sole) off-field
landing I made in the HP I used a rectangular pattern, just because the chosen
field was huge, with a no-brainer approach, and I could.
- - - - - -

> What is the military's track record wrt 'Stall-spin in the pattern'? Does
> it happen just as often with the 'Single 180 Turn...'?

Good luck obtaining hard data on this front! I've read (can't recall where)
the Navy's approach-to-carrier-landings accidents (metric unknown) dropped by
a factor of 3 when they post-WW-II adopted the circling approach in
conjunction with "flying AOA" (early 1950s?). I'd love to see that data.

Bob W.

[Dan Marotta]

I'm in the 180 descending turn to final camp and, flying downwind much
closer than the "squares" I spend half my time watching my touchdown
point and the final approach path for unannounced traffic on long final
approaches. It's no big effort to look out on final during the turn
while monitoring my intended touchdown point.

Having said the above, I think any pilot will make better patterns if he
flies them as he was taught and has practiced. Of course, you can learn
and practice the other method but you won't be quite as good at it until
your experience at it improves. Have fun and fly safe!

--
Dan, 5J

[waremark]

It sounds as though what we teach in the UK may be a little different to the USA approach (sorry for the pun).

We divide the downwind to base turn into two approximately 45 degrees turns, to insert a 'diagonal leg'. After passing low key, instead of continuing a long way downwind to make a rectangular circuit, we turn 45 degrees onto a diagonal, and later make another 45 degree turn onto a shorter base. Advantages over the rectangular circuit are keeping the landing area in site, and maintaining something closer to a constant glide angle to the reference point, which makes it easier to judge whether too high, too low or about right. It is a matter of judgement how soon or how far after passing low key to turn onto the diagonal.

[tkn...@earthlink.net]

Sorry to be so flip with my first response, however subjects like this keep coming up. Bottom line - there is a best practice technique for most tasks. Many of these best practices are designed to result in the safest methods.

From this "best practice" there develops alternative methods. Some of these other methods are for good reason, but they do not supplant the reasons for the best practice method.

This is a big subject, and I have submitted a lengthy article regarding landings for publishing in Soaring Magazine - probably after the first of the year.

Gather your stones for throwing.

Tom Knauff

[Charlie M. (UH & 002 owner/pilot)]

Whatever method you use, if you don't make a controlled arrival to the ground, you still broke something.
Even a "normal day at normal field" can bring surprises..........
Have a plan, make adjustments as required......
Don't break the glider, you won't likely break yourself.

[son_of_flubber]

On Thursday, July 28, 2016 at 5:43:41 PM UTC-4, tkn...@earthlink.net wrote:
> Sorry to be so flip with my first response, however subjects like this keep coming up.

I tried the 'Inverted Flight Landing Pattern' and I DID NOT LIKE IT.

Looking forward to your article on landings.

[son_of_flubber]

On Thursday, July 28, 2016 at 5:36:38 PM UTC-4, waremark wrote:

> We divide the downwind to base turn into two approximately 45 degrees turns, to insert a 'diagonal leg'. After passing low key, instead of continuing a long way downwind to make a rectangular circuit, we turn 45 degrees onto a diagonal, and later make another 45 degree turn onto a shorter base.

And then you make a 90 degree turn from base to final?

[Paul Rice]

At 00:26 29 July 2016, son_of_flubber wrote:
>On Thursday, July 28, 2016 at 5:36:38 PM UTC-4, waremark wrote:
>
>> We divide the downwind to base turn into two approximately 45 degrees

>tur=

>ns, to insert a 'diagonal leg'. After passing low key, instead of

>continuin=

>g a long way downwind to make a rectangular circuit, we turn 45 degrees

>ont=

>o a diagonal, and later make another 45 degree turn onto a shorter

base.=20

>
>And then you make a 90 degree turn from base to final?
>

Yup

[wby0...@aol.com]

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.

While it is true that many of you normally performing well trained pilots can safely fly all kinds of approaches, common sense suggests training and establishing flying habits that are more likely to result in safe outcomes when normal conditions and normal performance deteriorates.

The fact that we are still debating these things in 2016 makes me want to beat my head against the canopy.

[Tango Whisky]

Le vendredi 29 juillet 2016 16:33:21 UTC+2, wby0...@aol.com a écrit :
> 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).

I'm sure you can elaborate on this...

[John Cochrane]

Some of the reasons for standard patterns rather than 180:
- it's what other traffic at airports expects. It's what most instructors checking you out on their planes, airports, BFRs, or FAA examiners expect.
- it gives you good time to look from base to see if there is other traffic on final
- many stall spin accidents come from overshooting base to final, then ham-handed corrections. That's more likely from a 180
- many off field accidents come from being too close to the field. planning a 180 puts you close automatically
- less adjustment room if things go wrong.
- A test: try doing your no-spoiler approach that way.

John Cochrane BB

[John Wells]

Another advantage of a standard-ish circuit, is that the focus is on preparing for the final turn -- you aim to have your final turn completed at a safe height (and speed) in a reasonable place.

There's no reason you can't do this in a 180 deg turn too, but my guess it that it somewhat reduces this focus if it's not trained well. It could potentially have you focusing on your reference point too early, flying more cramped-in circuits as a result?

[Dan Marotta]

Yesterday, as I held short for takeoff, I watched a Grob overshoot final
out of a "square" pattern. It appeared to me that the pilot did not
check, comprehend, or compensate for the crosswind from the right on
downwind (left-hand pattern), and the wind blew him across the final
approach requiring a great steepening of the bank to pull it back around
and then a turn reversal to line up with the final approach. Note that
there was a CFI-G on board and I'll assume that he was letting the
student make the mistake as a training event.

My opinion on the turning approach is that it gives me continuous
feedback as to my ground track and allows me to continually correct for
the effects of cross winds. Of course I listen to AWOS entering the
pattern and set up a crab on downwind for the expected drift, and
correct that as required. I also watch the final approach course on
downwind and during my turn to final.

This is not rocket science, it's being aware of your situation and
surroundings, a condition less and less apparent these days. And
frankly, it's a lot easier, for me at least, to note and correct for
wind drift during a turn than to notice any effect of a tail wind while
flying a square base leg and then overshooting during the turn to final.

--
Dan, 5J

[Paul Agnew]

For students in any type - SEL, Rotorcraft, Glider - having a final approach "box" to hit gives clearer feedback on the approach than a slick turning arrival. At the expert level, I can accept that the continuous turn is more fun, but for low-time pilots it really helps them check their progress if they know they should be close to a specified altitude at a specified distance from the landing zone. Of course, there are adjustments for winds, but being able to instantly evaluate whether you're higher or lower than target helps you make immediate corrections. TLAR works better for experienced pilots.

I remember going up with a friend who was a newly certified Private-SEL. His approaches and landings were all over the place until I showed him how to crosscheck himself by looking for 500' at 1/2 mile on final. With that in mind, he was able to mentally project his progress better and make quicker adjustments.

Paul A.
Jupiter, FL

[Bob Whelan]

On 7/29/2016 8:33 AM, wby0...@aol.com wrote:

> 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.

Hey Matt, howzis for a data point? The 2nd-most-stressful landing approach I
ever made (microburst [just like #1 & #3] - not recommended for the
faint-hearted!) was done in the Zuni to a (shortish, with drop-off to an
arroyo at the threshold) prairie runway on which I'd never before landed (Owl
Canyon's SE one), from a close-in circling approach, with zero flaps until
v-e-r-y short final, begun from overhead the field at ~3,000' agl and
completed with (essentially) only a 270-degree turn from crosswind to final.
Gives me the mild shakes just recalling it!

Judging the "lower altitude bits" angle of bank was trivially easy compared to
deciding when to steepen the "downwind" portion of the turn into the "downwind
to final" portion. Why? The breathtaking descent rate (estimated later at
~3,000 fpm) "visually overwhelmed" the normally-to-be-expected sight picture
for "normal conditions." How bad was it? It nearly gave me heart failure, when
- for a brief, "I didn't, did I?!?" moment on downwind - the *vertical* ground
rush (contrasted with the downwind's seemingly-absent, more expected,
*horizontal* rush/related rapid progress over the ground) made it seem as if
I'd turned the wrong way onto downwind. I knew I hadn't, but it alarmed me so
much I "wasted" a few moments looking back over my left shoulder just to see
if there was still dust blowing from the SE immediately off the east end of
the target runway. (If I'd turned upwind rather than downwind, a serious
accident would likely have been in my immediate future.) The microburst
downwind sight picture and "over the ground feel" was more akin to what you'd
expect from turning downwind the wrong way on a "normally breezy day...i.e.
agonizingly slow progress over the ground in conjunction with a dismal
L/D....sort of like flying through molasses in terms of "expected downwind
progress." Despite trying to make a conservatively judged approach - e.g. not
planning a base much beyond the approach threshold, etc. - for a while it was
looking as if base would be made entirely within the shortish (2,000'?) runway
length...and crosswind had been at midfield!

As it was, I straightened up on final *maybe* 300' beyond the lip of the
dropoff (quite possibly less...no one on the ground saw the approach to share
their estimates), but I was too focused on judging final approach to give that
estimate much attention. Thermalling-flaps-only until past the threshold lip,
and still several hundred feet aloft; down and stopped well before midfield
after not using the wheel brake (trying to minimize the walking retrieve -
stress removed, we humans revert quickly to "energy saving mode," ha ha!).

I'd reckon prolly 95-98% of my attention throughout the approach was devoted
to "getting the approach path correct" with the remainder being "the usual"
airspeed/coordination cross-checks. There was very little "waiting for the
situation to develop" aspect to this approach, as is typically the case in
more routine patterns. Thanks to the sink rate, things developed "all too
quickly!" as in from 3,000'agl atop midfield. followed by two quick,
thermalling-flaps-only, 360s and on the ground. The first 360 was to clear the
pattern, positively locate a 1-36 I'd figured would opt to land before I did
(he turned out to be clueless, afterward, but got away with it just fine!),
and indubitably verify ground winds (as in "Where in heck is the center of the
downburst?), the second one was the pattern itself.

I don't remember my target pattern airspeed, but it likely wasn't all that
much higher than normal, because throughout, the air - other than being
abbie-normally descendant - was astoundingly smooth, so the primary airspeed
tasks seemed likely to be "only" retaining sufficient energy to deal with
low-level shear while not "overdoing" things. Control wasn't an issue (not the
case with #1 alluded to earlier, and to a lesser extent, #3).

- - - - - -

> While it is true that many of you normally performing well trained pilots
> can safely fly all kinds of approaches, common sense suggests training and
> establishing flying habits that are more likely to result in safe outcomes
> when normal conditions and normal performance deteriorates.

I agree with your general sentiment, but would add that "actual reality" is
the ultimate arbiter of "what must be done" in every landing pattern. Under
the above conditions, I doubt I could have pulled off "a full rectangular
pattern" that wouldn't have terrified me even more than the one performed, due
to the (almost certainly likely) need to turn final well within the runway
western/downwind boundary, and (at some point) to be facing a rapidly
decreasing headwind...my overshoot concerns weren't far behind my undershoot
concerns. As with undershooting, the overshooting options on that runway are
nonexistent, short of barbed-wire fence/railway
embankment/fence-in-borrow-trench/interstate highway/fence/etc., or, (major
yikes) trying to convert to a howling crosswind landing to the south on open
prairie. I dunno if the preceding explanation makes sense, but under the
circumstances and at the time, an "analog" circling pattern seemed more
amenable to fine-tuned approach adjustments than did a "digital" rectangular
pattern, while also likely maximizing runway ahead without wasting runway behind.

I didn't "originally plan on" a circling pattern, it simply seemed the best
and most natural of the available options...and worked superbly.

- - - - - -

> The fact that we are still debating these things in 2016 makes me want to
> beat my head against the canopy.

Aw, c'mon - please don't. The latest scientific evidence suggests doing so can
be harmful to canopies: plastic and cranial (and, the latter's contents)! A
baseline landing pattern standard is a great thing for many reasons...but I
see no fundamental harm in assessing why (and why not) it may not be the cat's
meow for *all* circumstances. You DO want your students to retain, and further
develop, their critical thinking skills, right? :)

Bob W.

[kirk.stant]

my $.02:

First, the beauty of the 360 "Overhead" pattern is that it makes it really easy to fly exactly the same pattern at ANY airfield. As long as you come up initial at the same speed, and pitch out at the same bank angle, you will end up at the same place on downwind (adjusted for x-wind, of course). The, you just configure, motor to the perch, and roll into your easy 180 turn to line up on final. Done well, it's one of the most satisfying maneuvers in aviation.

And it has the advantage of being a really quick way to enter the pattern, slow down, and land - useful for towplanes.

BUT - it's meant for relatively fast movers with bigger turn radius's; works fine in a Pawnee at 120 mph, no so good in a J-3 at 65 mph, and not at all in most gliders (yes I've tried).

So, for gliders, all that is really useable is the second half - the continuous 180 degree turn to final. As others mention, that is not what is normally taught, and has some limitations that need to be taken into consideration; the main one is that it has to be done from a low downwind, and it happens fast.

And that is why I think it is actually a useful skill to practice: If you end up low and tight, you should be able to fly a safe 180 (or 270, or 90) pattern and land out of it - because you don't have the option of going around!

Just realize that most other traffic will not be expecting it and fly accordingly.

In regards to you question about the military's track record - I don't have numbers but would bet an expensive bottle of whiskey that it's a LOT better than that of GA - after all a military pilot is better trained, flies more often, gets lots of check rides, etc. That being said, modern military jets are more susceptible to high-sink rate problems in the pattern that stall/spins; look up almost any T-38 accident and getting low and slow on final will pop up often. For a supersonic jet, it is really a dog when slow!

Kirk
66

[wby0...@aol.com]

Bob W wrote, "actual reality" is

the ultimate arbiter of "what must be done" in every landing pattern.

I'm not saying that everyone should always fly square approach patterns. I'm saying that in glider operations straight legs with well-banked instead of shallow continuous turns are a generally safer way to operate and train.

[wby0...@aol.com]

And that there are well established aerodynamic and human factors to support this as best practice.

[BobW]

On 7/29/2016 1:10 PM, kirk.stant wrote:

<Snip...>

> So, for gliders, all that is really useable is the second half - the
> continuous 180 degree turn to final. As others mention, that is not what is
> normally taught, and has some limitations that need to be taken into
> consideration; the main one is that it has to be done from a low downwind,
> and it happens fast.

I don't comprehend why a circle-from-downwind-to-final landing pattern in a
glider "...has to be done from a low downwind, and it happens fast." I
understand it CAN be done that way, but not why it MUST be done that way.

If Joe Glider Pilot is aiming to produce a threshold landing directly from the
180-degree turn, I suppose an overall lower flight path compared to the case
where he seeks to achieve the same "no straight final leg" threshold landing
directly from the base-to final turn would be the case, simply because the
latter/"tangencies-to-the-circle" flight path pattern would be longer due to
the "uncut corners," and hence the "rectangular path" pattern has greater
distance over which spoilers can be modulated. (The preceding scenario assumes
a "normal downwind offset distance;" the closer in the final, the less
additional distance flown, of course.) But if the goal is "simply" to hit a
pre-selected landing spot on a runway, he can also do "the circling thing" to
final, rolling out short-of and "normally above" the runway onto his final
approach path...which is what all of my "circling patterns" sought to achieve.
IOW, my circling-to-final in the HP allowed me to be able to use less bank
angle-per-unit-time (aka lower roll rate/stick forces) to a high, straight,
final approach path; I wasn't trying to emulate Joe Carrier Pilot in any way
beyond borrowing his 180-degree downwind-to-final turn. Likewise, the
microburst-influenced "fully circling pattern" described in another post, in
actuality, by design, resulted in a (very) short straight final.

Tangentially and as noted elsewhere, for whatever reason, I found no
difference in difficulty judging "howzitgoing" with respect to my glider's
status "in the descent cone" whether circling from downwind to final or using
separate, distinct, 90-degree turns to get there...if anything, the circle
seemed "more natural" to me..but then I preferred playing outfield to infield
as a kid! Either way, every pattern's goal: to arrive on a straight final
"somewhere on the high side" of my ship's theoretical descent cone.

Back to my original puzzlement...am I correct in believing "military approved"
circling approaches essentially do NOT include "a straight final" portion,
a-la the "immediately before touchdown" curving flight path understandably
employed by (e.g.) Pitts biplane pilots as a means of retaining over-the-nose
vision for as long as possible until the runway edges appear on either side of
the nose?

> And that is why I think it is actually a useful skill to practice: If you
> end up low and tight, you should be able to fly a safe 180 (or 270, or 90)
> pattern and land out of it - because you don't have the option of going
> around!

"Roger that!" on the go-around-impossible bit. (No mulligans in sailplane
landing patterns!) When I blundered into the sport, the concept of being
unable to "re-do a poor pattern" by going around was a
new/completely-foreign/ignorantly-scary concept to my "power-polluted" (in the
reading sense of things) brain. Upon becoming "stick-time/usefully familiar"
with the flight physics of sport sailplanes, the no-go-around reality quickly
mentally-morphed into "entirely normal and not a big deal"...so long as
reasonable and continuing assessment of "minding the approach store" was part
of the piloting package. It was immediately clear to me "an easily repeatable"
landing pattern was the primary tool in minding the store.

And "Roger that!" on being able to safely do (or more accurately, salvage, if
previous inattention/screwups have contributed, sardonic chuckle) low
patterns. Following "licensure," safely expanding one's flight envelope surely
is the name of the aviation game! So - where do I go to practice departures
from controlled flight *in* my landing pattern? :)

Bob W.

[uncl...@ix.netcom.com]

I would be curious as to why you think you like the single 180 degree turn better than the conventional rectangular pattern.
Care to explain?
UH

[son_of_flubber]

On Friday, July 29, 2016 at 7:03:37 PM UTC-4, uncl...@ix.netcom.com wrote:
> On Wednesday, July 27, 2016 at 7:33:48 PM UTC-4, son_of_flubber wrote:

> > Having recently tried the 'Single 180 Turn...' and LIKED it,

> I would be curious as to why you think you like the single 180 degree turn better than the conventional rectangular pattern.
> Care to explain?
> UH

My strong preference is for the conventional 'square' pattern. Here is a recap on my sole '180' pattern and a guess about what felt right.

I'm using an .igc file at one second intervals to aid recollection.

My default procedure is to set spoilers to 50% open, then adjust pattern shape to make my aim point. In this case, I encountered lift on downwind, so I opened spoilers before turning to base. We had had a lot of low altitude slack rope on tow and I was anticipating similar on the way down.

I started to turn base early due to my chosen airspeed, my sink rate and a strong crosswind pushing me away from the runway. I realized right away that I had started to turn prematurely, and decided to 'fly base on a 45 diagonal' relative to the runway (instead of 90 degree square) in order to place my 'turn to final' farther from the threshold.

At this point, I had just started to bank for the turn to base, so my bank angle was not steep yet, and for no deliberate reason, I held the bank angle steady as I tried to read where the glide slope was going to intersect the ground and how the crosswind was affecting the flight path. The crosswind reduced my rate of turn.

I have a tendency/preference to hold control inputs steady and evaluate the result.

Referring to the flight path recorded in the .igc file I see that when I completed 90 degrees of turn, I opted to increase the bank to make the additional 90 degrees of turn. From to the .igc, I completed the turn 300 feet above my touchdown point. (Given the slot cut in the forest that we fly through on final, and the possibility of sink, this height is just about right.)

I flew two connected shallow 90 degree turns, not a true 180 constant bank turn from downwind to final (that's harder I expect). I assume that there is some similarity. I liked that it seemed rather easy to judge the intersection of the glide slope with the ground. My compensation for crosswind was gradual because my heading changed gradually. It seemed easy to keep my chosen airspeed rock steady (2X stall speed). It seemed easy to align final with the runway. Because everything was smooth, gradual and consistent, it was easy to evaluate how things were going and make small adjustments as needed.

I did not set out to fly a '180 turn pattern'. It happened. I accidentally deviated from my training and 'best practices'. I'm reporting and not advocating. I'm looking for perspective.

[Tango Eight]

On Saturday, July 30, 2016 at 12:51:25 AM UTC-4, son_of_flubber wrote:
> My default procedure is to set spoilers to 50% open, then adjust pattern shape to make my aim point.

I'd like to hear some well experienced CFIGs weigh in on that statement. Email fine if you don't want to feed the frenzy here.

best,
Evan Ludeman (rookie CFI)

[Dan Marotta]

On 7/29/2016 4:19 PM, BobW wrote:
> Back to my original puzzlement...am I correct in believing "military
> approved" circling approaches essentially do NOT include "a straight
> final" portion, a-la the "immediately before touchdown" curving flight
> path understandably employed by (e.g.) Pitts biplane pilots as a means
> of retaining over-the-nose vision for as long as possible until the
> runway edges appear on either side of the nose?

It's been quite a long time, but as I recall, the roll out on final was
around 1/2 - 3/4 mile from touchdown and that goes pretty quickly in a
jet. The way I currently fly the glider, it's closer to 1/4 mile from
completion of the turn to the touchdown point. I try to make my final
approach about the same flight time (vs. distance). Years of practice
have made this pretty routine.
--
Dan, 5J

[tkn...@earthlink.net]

As reported in the not very popular booklet, "Preventing Landing Accidents," (another important book very few glider pilots in denial have bothered to read.)

64% of fatal glider accidents occur during the landing phase.

64% !!!

There is no reason for disagreement of a proper landing technique.

Tom Knauff

[Michael Opitz]

I took my CFIG check with an FAA examiner as an 18 year old back
in 1969. On the second flight, the examiner had me cover up the
altimeter at about 1500' overhead the airport, and then told me to
do continuous circles until it was time to roll out and land. I did it,
and made my spot landing too. He told me it would be good
practice for judging an off-field landing where I didn't know the
terrain elevation.

Rectangular traffic patterns on uncontrolled civilian airports are
probably the safest (because other pilots know where to look to find
you), and give you as a pilot the chance to clear for others
blundering into your space before you make each turn. It is also
easier to teach because you can set altitudes to hit at certain check
points along the way. It makes for a cookie cutter pattern that will
keep a student safe as long as they set it up properly. The problem
with soaring is that Murphy always rears his head, and glider pilots
get presented with non cookie cutter situations to deal with. That's
where learning "judgement" comes into play. If the student winds
up caught downwind with sink, will the judgement be there to
realize they don't have the altitude to do the cookie cutter pattern
any more? I have personally witnessed 2 occasions where the
person flew the "correct" ground track, but wound up in the trees
short of the runway because they started the pattern too low.
Judgement is not an easy thing to teach, but it is vital to learn.
Pilots need to be able to recognize things and circumstances have
changed, and be able to adapt to those changes on a running basis.
If that means doing a tight 180 degree turn to intercept the desired
final glide path prior to touchdown at the desired point, the pilot
has to be able to adapt to that. If it means flying a mirror image
traffic pattern from the other side of the airport because that's all
that altitude and energy will allow any more, they have to have the
judgement to realize that's what is required to get on the ground
safely. That is the hard part to teach...... You have to be able to fly
and chew gum at the same time. Some pilots get so locked in on
one thing that they don't see the real danger coming from another
approaching issue...

Overhead 360 degree traffic patterns were lots of fun to fly in the
military, and are a great way to safely recover a bunch of aircraft in
a very short period of time. Doing the Space Shuttle like SFO
(Simulated Flame Out) approaches from 8000' overhead at 215
knots in an F-16 were a blast. All of these are generally done in a
controlled traffic environment where you (for the most part) don't
have to worry about someone blundering into your way once you
have clearance. These patterns also have their place and time.

For civilian glider operations on uncontrolled airfields, the standard
rectangular patterns that everyone expects to see (and clear for)
are the way to go, with the caveat that one has to get the glider on
the ground safely. If circumstances dictate doing something other
than the standard robotic pattern in order to get on the ground in
one piece, then judgement has to come into play, and things will
need to be modified as necessary to yield a positive final outcome.

RO

[uncl...@ix.netcom.com]

This sounds like someone experimenting to try to find a better way than the proven rectangular pattern that works well for most every flight. Obviously adjustments need to be mad periodically.
Maybe we need a thread on do it yourself brain surgery.
I hope low time folks don't take this stuff to heart.
UH

[son_of_flubber]

On Saturday, July 30, 2016 at 8:50:08 AM UTC-4, Tango Eight wrote:

> On Saturday, July 30, 2016 at 12:51:25 AM UTC-4, son_of_flubber wrote:
> > My default procedure is to set spoilers to 50% open, then adjust pattern shape to make my aim point.
>
> I'd like to hear some well experienced CFIGs weigh in on that statement.

What I left unsaid, because I thought it was understood, is that the pilot will first adjust the spoilers moderately, and then if necessary, change the heading of the base leg.

You want a CFIG to weigh in?

To quote Tom Knauff from 'Preventing Launching and Landing Accidents' page 27

"After the turn onto the base leg, the pilot has two plans of action in case the apparent final approach glide angle appears too steep or too shallow. If the slope appears too steep, the pilot uses a plan of action to open the dive brakes and angle away to extend the glide path to lose some altitude. If the glide angle appears too shallow, the pilot will immediately close the dive brakes and turn towards the landing area." Copyright 2004 Knauff and Grove

A schematic figure that shows a non-rectangular pattern follows immediately in the text.

On page 26 "The dive brakes of a typical modern glider will allow the glider to descend anywhere from 5:1 to a very conservative 20:1. The pilot should never be very close to either of these extremes." Copyright 2004 Knauff and Grove

Based on this and other things written by Tom, I conclude that aiming to keep the spoilers near 50% effectiveness gives the pilot the most flexibility (either way) to compensate for things that don't go according to plan. That's my default (goal) as previously noted.

So changing the heading on base leg (non-square pattern) is a Knauff-recommended means to recover from an incorrectly timed turn to base. That said, almost all of my patterns are square, my turns are steep, and my spoilers stay open to about 50% until I touch down.

If my pattern speed needs to be higher to deal with wind and turbulence, I'll delay opening the spoilers, and if conditions are intimidating, I might turn to base a bit early, so that I have more reserve to deal with the possibility of extraordinary sink, and if it turns out to be just ordinary sink, I'll add a little more spoiler on final to get down.

In the last 30 days, I've flown glider on 13 days, and because I think safe and optimal landing is utterly important and merits practice, I've landed 21 times, (and as often as possible in utter crap conditions in order to stay proficient). So if you think I'm a mad anarchist pilot trying to tear down the status quo, then I've communicated poorly and/or you're projecting something that isn't there.

[Tango Eight]

No, I'm not projecting anything. I just wanted to see if the very experienced guys had a different take on your story than I did.

FWIW, putting the *priority* on maintaining spoilers half open, and adjusting the pattern to keep it that way struck me as profoundly odd. In fact I'd rate it right up there with the advice in Joy of Soaring about how to fly the final approach**: it's precisely backwards. Sure, you can make it work. That doesn't make it a best practice.

The normal procedure for correcting glide slope is to use more or less spoiler to capture the desired glide slope for the pattern being flown. Adjustments to the pattern are sometimes necessary or desirable, and the ability to make these adjustments when needed is essential skill for any glider pilot. The passages you've quoted from Tom's books are fine as far as they go, I simply think you've misunderstood the application. Generally, one can make corrections for all but the grossest of errors with spoilers alone. In the case of a really big error (or rotor, or big wind shear or whatever), then you add the pattern variations as Tom describes.

**The Joy of Soaring approach to final approach was this: aim with the nose (in pitch), control airspeed with spoilers.

best,
Evan

[Giaco]

Evan,
Flying a pattern with the intention of 50% spoilers is to provide the safety buffer in both directions (high and low), rather than needing to adjust your ground track and preserve the sacred rectangular pattern. While you are completely correct that most spoilers can cure your excessive altitude problems in the pattern, if you fly a pattern that is sized to not need any spoilers/airbrakes and you are too low, you must now change your pattern rather than closing the airbrakes a bit. It is mostly about making the size of your pattern halfway between what would be required for a no-spoilers pattern and a full spoilers pattern.

Chris

[Tango Eight]

Hi Chris,

In a word -- baloney! Read it again:

On Saturday, July 30, 2016 at 12:51:25 AM UTC-4, son_of_flubber wrote:
> My default procedure is to set spoilers to 50% open, then adjust pattern shape to make my aim point.

That is a very different SOP / not something I ever do / not something I plan to teach / something I would likely intercept and work on correcting if a pilot brought it to my club.

I like Tom's emphasis on best practices.

See ya,

Evan

[John Carlyle]

Maybe I misunderstood, but Flub’s description of his approach technique seems very mechanical and/or contrived. To me it seems very similar to how I was taught in a 2-33 using Joy of Soaring, except instead of “being at 500 feet over the red barn” he keeps 50% spoiler and moves his ground track toward and away from the airport.

Tom Knauff transitioned me into my ASW-19 at Ridge Soaring, and of course he taught me to use TLAR. What I took away from him was to “always look and judge how the approach is going”, and to do what you had to do with the controls to put the glider into the proper position. Those of you who’ve flown at Ridge Soaring know that the approach to 25 is never amenable to recipe flying...

Tom’s TLAR has served me well during both routine and very tricky approaches. Honestly I couldn’t tell you where my spoilers are, unless I hit either the forward or aft limit while reacting to extreme sink or lift. But I can always tell you if I’m too high or too low! And during every approach I always hear my instructor Jack chanting “airspeed, yaw string”, over and over.

-John, Q3

[Matt Herron Jr.]

One consideration I don't think was mentioned; A straight base leg gives the pilot a chance to really look hard for head-on traffic in the opposite pattern. A situation that killed a friend of mine.

Matt

[tkn...@earthlink.net]

I may have mentioned this before, but the series of my articles and tests currently being printed in Soaring magazine will continue for a few more months. As a result of this discussion, I am submitting a rather lengthy article about landing procedures / technique. My guess is it will not be published until early next year.

If I send in two pages of my popular Glider Flight Training Manual each month, it will take 15 years to publish all the information it contains.

You might consider upgrading to this new version rather than waiting.

Tom Knauff

[2G]

I thought of four situations when this "military",or button hook, landing pattern MIGHT be appropriate:

1. Terrain/buildings forced a tight base leg, such as an airstrip in a canyon.
2. Remaining altitude is at an absolute minimum for landing.
3. Unusual local weather conditions, like microbursts, are occurring.
4. The pilot wanted to impress his/her girl/boyfriend (just JOKING!).

In all other situations a square pattern (or a modified square pattern) is far safer. Flying a button hook pattern puts the runway out of sight to the pilot, so it is hard to judge how far you have flown, making it much more likely that an overshoot or undershoot landing will occur.

An important aspect of the square pattern, in addition to the visibility part, is to assess the winds aloft by the amount of crab required. I have been flying lately in conditions of high cross winds (10-20 kt) and even higher gusts (20-30 kt). Having a stabilized base leg is essential to judge this (the AWOS is just to old to be relied upon). If I were to fly a button hook pattern I would have a ground speed of 110-130 kt, given the high density altitudes we are flying and an 80 kt IAS (100 kt TAS + 10-30 kt tail wind)! 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! You may not experience these conditions where you fly, but a lot of accidents occur when flatlanders venture into high density altitude airports.

I also like to have A LOT of altitude when entering the pattern (2,000 ft). It is easy to burn off that altitude in modern gliders and it gives me options if something unexpected happens (like a plane pulling out onto the runway unannounced). Altitude lost is like runway behind you - it doesn't do you any good.

Tom

[Giaco]

> Hi Chris,
>
> In a word -- baloney! Read it again:
>
> On Saturday, July 30, 2016 at 12:51:25 AM UTC-4, son_of_flubber wrote:
> > My default procedure is to set spoilers to 50% open, then adjust pattern shape to make my aim point.
>
> That is a very different SOP / not something I ever do / not something I plan to teach / something I would likely intercept and work on correcting if a pilot brought it to my club.
>
> I like Tom's emphasis on best practices.
>
> See ya,
>
> Evan

Sorry, i totally misread that... That pattern makes no sense to me then if you are just setting an arbitrary airbrake setting and building a pattern around it.

[Dan Marotta]

In all other situations a square pattern (or a modified square pattern) is far safer. Flying a button hook pattern puts the runway out of sight to the pilot, so it is hard to judge how far you have flown, making it much more likely that an overshoot or undershoot landing will occur.

What???  I always fly a descending 180 to short final and I never lose sight of the runway.  What are you doing that puts you in that position?  It's trivial to keep the landing point in view over your shoulder until you begin the turn, unless you're flying way too far out before beginning your final.

An important aspect of the square pattern, in addition to the visibility part, is to assess the winds aloft by the amount of crab required. 

It's easy to assess winds on downwind and continuously through the final turn without losing sight of the touchdown point. Drift is recognized with peripheral vision and quick glances down at the ground.  Final and opposite patterns are monitored from downwind throughout the final turn.  Angle of descent is easily controlled by keeping the angle to the touchdown point constant.

I have been flying lately in conditions of high cross winds (10-20 kt) and even higher gusts (20-30 kt). Having a stabilized base leg is essential to judge this 

As said above, it's easy to judge during the downwind and throughout the turn.

 (the AWOS is just to old to be relied upon).

Very true!

 If I were to fly a button hook pattern I would have a ground speed of 110-130 kt, given the high density altitudes we are flying and an 80 kt IAS (100 kt TAS + 10-30 kt tail wind)! 

Why would you have a higher ground speed in turning flight than in straight flight?

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!

No, you're close enough that reducing dive brake will compensate for any sink.  If you're in a location with known high sink on final, e.g., Salida, CO, you should make your turn at the proper height and distance from the runway.

 You may not experience these conditions where you fly, but a lot of accidents occur when flatlanders venture into high density altitude airports.

I also like to have A LOT of altitude when entering the pattern (2,000 ft).

There goes flying where other pilots expect to see you!

 It is easy to burn off that altitude in modern gliders and it gives me options if something unexpected happens (like a plane pulling out onto the runway unannounced). Altitude lost is like runway behind you - it doesn't do you any good.

Tom

Fly what works for you and don't disparage techniques that are out of your sphere of experience.

--
Dan, 5J

[Tango Eight]

On Sunday, July 31, 2016 at 10:32:02 PM UTC-4, Dan Marotta wrote:

> Fly what works for you and don't disparage techniques that are out
> of your sphere of experience.

...pop quiz then.

You're #3 in the pattern behind a student in a 1-34 flying a standard glider pattern and a tow plane. Behind you is another student + CFI in an L-23. What kind of pattern are you going to fly, and why?

I think there's a right answer to this question.

best,
Evan

[kirk.stant]

On Monday, August 1, 2016 at 6:59:04 AM UTC-5, Tango Eight wrote:

> ...pop quiz then.
>
> You're #3 in the pattern behind a student in a 1-34 flying a standard glider pattern and a tow plane. Behind you is another student + CFI in an L-23. What kind of pattern are you going to fly, and why?

Situation number 2: You enter the pattern a bit low (so not enough to orbit) and a student in a L-23 enters the pattern behind and below you - what kind of pattern are you going to fly and why?

There are times when a big "bomber" pattern are necessary and safer; there are also times when you have to get on the ground as fast as possible. A competently trained pilot can adapt to whatever situation is encountered and fly accordingly.

kirk
66

[Eric Greenwell]

2G wrote on 7/31/2016 4:07 PM:
> I also like to have A LOT of altitude when entering the pattern
> (2,000 ft). It is easy to burn off that altitude in modern gliders
> and it gives me options if something unexpected happens (like a plane
> pulling out onto the runway unannounced). Altitude lost is like
> runway behind you - it doesn't do you any good.

I like to have a lot altitude in the pattern, generally entering at 1000
feet agl. I don't like to be any higher, because I worry about
descending onto aircraft below me in the standard pattern (they can be
hard see, and usually are not looking up for aircraft above them). To
avoid that, I descend away from the airport, watching below me, until I
can make a "standard" 45 degree entry to downwind, arriving there in the
1000' - 1200' range. I don't use spoilers until I've turned final, so my
turns to base and to final are relatively high.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-Launching Sailplane Operation"

https://sites.google.com/site/motorgliders/publications/download-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/Guide-to-transponders-in-sailplanes-2014A.pdf

[Tango Eight]

So: what type of traffic pattern allows the greatest degree of flexibility to meet the needs of a wide variety of situations (traffic, weather, etc.)?


Where I'm going with this: the guy who has made up his mind 5 (or 500) miles out what sort of pattern he is going to fly ("I always...") and sticks to that plan like glue is a pain in the ass (at best).


best,
Evan

[Bob Whelan]

On 8/1/2016 9:34 AM, Tango Eight wrote:
<Snip...>

>> There are times when a big "bomber" pattern are necessary and safer;
>> there are also times when you have to get on the ground as fast as
>> possible. A competently trained pilot can adapt to whatever situation is
>> encountered and fly accordingly.
>>
>> kirk 66

Completely agree...

> So: what type of traffic pattern allows the greatest degree of flexibility
> to meet the needs of a wide variety of situations (traffic, weather,
> etc.)?

Is this a trick question? :)

> Where I'm going with this: the guy who has made up his mind 5 (or 500)
> miles out what sort of pattern he is going to fly ("I always...") and
> sticks to that plan like glue is a pain in the ass (at best).
>
> best, Evan

Completely agree with the PITA bit...nor do I see any fundamental conflict
between the above two views. "Choose wisely," is a great aviation mantra.

FWIW, the only two times I've been "surprised" in the pattern at Boulder (CO,
described earlier in the thread) was from bozo (as in both were experienced
enough and "should have known better [than to do what they did])" glider
pilots, one a visitor, one a local, who entered the pattern (very) late (and
low) from non-standard directions for prevailing conditions, necessitating I
alter my pattern plans, for separation and safety. "Properly educating" locals
is relatively straightforward; the visitor never reappeared & I have no idea
if he learned anything useful from his self-inflicted "idiot's pattern." It
easily could have had something of a bad snowball effect, depending on the
skills and experience of the others in the pattern just then (and there were 2
more in addition to me, as I recall).

Why anyone would thoughtfully choose to fly those sorts of patterns under
busy, benign-weather, conditions is beyond my way of thinking...

Bob W.

[kirk.stant]

On Friday, July 29, 2016 at 5:19:53 PM UTC-5, BobW wrote:

> I don't comprehend why a circle-from-downwind-to-final landing pattern in a
> glider "...has to be done from a low downwind, and it happens fast." I
> understand it CAN be done that way, but not why it MUST be done that way.

Because you are taking out the base leg - and the altitude and time spend exiting the first 90 degree turn, flying the base leg, then entering the second 90 degree turn to final. All this takes time and altitude so either you fly a tight, low downwind and 180 to final, or you fly higher and wider and use 2 90s (or 2 45s and a 90). That's assuming you want to use reasonable angles of bank, not a real shallow 180 turn.

> Back to my original puzzlement...am I correct in believing "military approved"
> circling approaches essentially do NOT include "a straight final" portion,
> a-la the "immediately before touchdown" curving flight path understandably
> employed by (e.g.) Pitts biplane pilots as a means of retaining over-the-nose
> vision for as long as possible until the runway edges appear on either side of
> the nose?

No, it is based on rolling out on final at a comfortable distance from the threshold to allow for the final lineup and xwind correction. In jets it was about 1 mile out, in a glider it can be closer but you still want a comfortable final. The old "continuous turn to touchdown" was used by WW2 fighters (and Pitts', BTDT!) where you couldn't see the runway over the nose on a straight final. But it works nicely in a glider if your front seat passenger has big hair! ;^)

In our sport you take whatever pattern entry you can and should be able to safely land. Yesterday I was working a weak thermal just off the end of our club's runway - I had notified ground ops where I was and could see that there was no conflicting traffic, and used the opportunity to work on low save/landout procedures - which didn't work so I just rolled out at 500' or so and landed straight ahead, rolling up to the clubhouse. No standard pattern, but good training, I think. Some may disagree, and that's fine. I've had to do the same in real landouts and I like practicing non-standard approaches in a safe environment (I was watching the pattern and could break out and land at any time if conflicting traffic appeared). Perhaps that is from military training where you often practice emergency procedures in the air - watch F-16s doing SFO (simulated flame out) approaches sometime - there is an exciting way to land!

Kirk
66

[Dan Marotta]

Hi Evan,

Of course you think there's a right answer because you're a proponent of the square pattern which, if you've read my posts, I'm not at all against.  I just prefer to fly the pattern which works best for me and to date, nobody has complained about.

That said, I start monitoring the local field from about 20 miles out and am aware of the traffic situation so I plan ahead and don't get into the situation of being #3 but should it still happen:

1.  I can reduce my speed considerably and pull up to give time to others.
2.  Take a thermal and climb
3.  Land on the parallel taxiway
4.  Land on the cross wind runway
5.  Land opposite direction (we have a long runway)
6.  Land way long
7.  Make a close in pattern in front of the 1-34 who's probably at twice my distance from the runway.  I'll be clear at the taxiway likely before he turns final.

I'm sure I can think of more ways to mitigate the situation but I don't feel constrained to drive an aircraft as though it were a train stuck on the tracks.  That's the main problem I see with "by the book" flying.  I'm not an outlaw and don't mean to come across that way, but I have to sniff when I'm told that there's only one right way to do something.  One of my EE professors back in the early 70s (an old German) used to sniff at what he called "cooking book engineers".  I took that to heart and try to do what I think is best for a given situation and what works best for me.  I understand that, as a CFI you're pretty much constrained to teach by the book, but let me ask you this:  Is there anything in the FAA's Glider Flying Handbook that you know to be wrong?  Do you teach it wrong if it's so published or do you teach it right? I do what needs to be done and yes, I could fly a square pattern in the situation you described. 

And another question:  Have you ever seen someone really get into trouble because the pilot in front of him in the pattern flew way too far out before turning base and #2 felt that he had to fly even further to maintain spacing?  I have.

Now please tell me your correct answer.  I'm genuinely interested and I've enjoyed this discussion and hope that others less experienced might undertake to learn to think outside the box.

Regards,
Dan

--
Dan, 5J

[Dan Marotta]

Bob,

I doubt anyone tried to fly a bozo pattern. Sometimes we get into a bad
situation and barely scrape home and do the best we can to salvage the
situation. Hopefully the "offending" pilot would apologize to all at
the airport for throwing the proverbial wrench into the works. I do
recall thermalling over a mall parking lot in Boulder once having
mistakenly followed a crow to the back side of the Flat Irons. I
thought it was a hawk and immediately regretted my decision. I don't
recall the pattern I flew that day.

--
Dan, 5J

[Squeaky]

Well, not that my answer matters much as I'm only a six year glider
pilot, but I do come from a USAF background.

All else being equal I fly a curved pattern all the way from downwind to
final. Flying that pattern does not stop nor preclude cross checks. I
do not stare at the land point all the way around. I check the opposite
base along my entire downwind leg. I check again throughout my pattern,
and I look for straight in traffic prior to passing the 100-110 degree
point where it gets under my belly. I also do not stop cross checks
into the cockpit to monitor airspeed, altitude and yaw string. That
constant cross check and outside look out has been ingrained in me for
years. Even on short final I look around, nod to the duty crew,
whatever. I have yet to see anything dangerous in this technique. I
was taught you fly a pattern to get you to final in the envelop/cone
where you still have correction ability on final--i.e. about half speed
brakes.

I also fly TLAR... My goal in the pattern, is to hit half brakes all
the way around the turn, never changing anything to fly a perfect
pattern, roll out, no changes until flare, then touchdown at my aim
point. I never quite get there, but that perfection goal challenges and
pleases me, and I get pretty close some times. I have been able to fly
the same pattern with multiple aircraft in the pattern (almost all of
whom fly wider than I do). If I can't time my pattern to follow someone
ahead and/or with someone behind, and not conflict with either no matter
how I fly, I've got no business flying. Heck, I've held on opposite
(right) base to let four gliders land who were in the opposite pattern
before I curved my way in behind them in the remaining space.

That said, I am more than capable of flying square patterns, and I
actually hit 45 degree or higher bank angles in my turns when I do. I
do this when winds are high as a matter of course--the long, lower bank
angle, continuous turn allows the winds to affect me more, and I prefer
the hard, shorter turns, and the wind corrections and min drag of the
straight legs and fast turns to the longer gentler draggier effects of
the continuous turn. Less wind drag, less wind effect with the
straighter legs it seems to me (i.e. more efficient approach).

My thoughts: my pattern keeps me closer to the field in case of rapid
deterioration of flight conditions or glider problems. I find it much
easier to visualize the cone and my approach to it as I'm flying it all
the way around the pattern. Since I do not have to time the final turn,
I have more time to do lookout, cross checks, etc as my flight inputs
are relatively minor corrections all the way around. if I need to get
down faster, outside rudder works great (practiced it on purpose, but
have never required it).

It does make other glider pilots, or instructors at strange field
checkouts a little nervous when they fly with me however, as they feel
tight and find the constant turn weird or different.... But they have
always said I've handled it safely and easily and got on final with zero
issues.

Squeak




--
Squeaky

[2G]

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

[uncl...@ix.netcom.com]

As an instructor I spend most of my time trying to get pilots to get in the box and stay there.
That box involves the use of a rectangular pattern with adjustments as needed for the situation at hand. Cook book- Yes. That said following a cook book doesn't often lead to disaster.
UH

[Tango Eight]

Hi Dan,

No, it wasn't a trick question (good one, Bob :-)), the answer is "the standard pattern".

My $0.02: There's no science, no engineering, no product development going on, just traffic sequencing for landing.

The standard pattern makes you predictable, adaptable within wide bounds, visible, unhurried. What's not to like? It's the perfect way to sequence.

If you have the pattern to yourself (which is often the case where I mostly fly), then knock yourself out. There's the guy that can precision park the G-103 ride glider every time without using the wheel brake, the 2-33 pilot who likes his no-spoiler, no wheel brake precision landings and the XC hotshots doing their low passes in formation. I love that stuff. But when it's time to share with other traffic, particularly other traffic that includes student pilots, the best practice is a standard pattern.

And yes, the glider handbook has some issues.

best,
Evan

[Dan Marotta]

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.  True, I don't know your experience, so why don't you tell me?  I've flown single, twin, and triple engined jets, single and twin recips, and twin turboprop beginning 43 years ago.  I've flown gliders for 30 years.  I've never damaged an aircraft in all that time including 5 dead stick landings due to engine failures.  I've flown 66 different types of aircraft.  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.  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.  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!

 

Maybe I misunderstood you, but didn't you make reference to 220 feet per second or 130 kts ground speed?  I'd need a 60 kt tail wind on downwind to achieve that kind of ground speed.  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.  How much?  Enough to fly a parallel ground track.  Did I fly past the end of the runway before beginning my 180 deg descending turn to final?  Heck no!  I started the turn at mid field since that was the location where I wanted to stop to clear the runway.  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.  If I'm wrong in that, I apologize.  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.  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.  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.  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.  I begin my turn from downwind at or just slightly beyond the threshold.  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.  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.  I've only argued that all of contentions that my way is unsafe are hogwash.  What works for me works for me.  Fly any way you want but please quit telling me that what I do is "unsafe".  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

[Dan Marotta]

Squeaky, you're so much more articulate than I am. Thank you for
telling it the way I tried to!

Dan

Dan, 5J

[Dan Marotta]

All good points, Evan. And, to be fair, our pattern is rarely clogged
with another aircraft so predictability is rarely an issue. And yes, I
can fly a square pattern and do occasionally, and I've made my
preference clear but my precision is better with a curved final turn so
that's what I use If I have to land out. Fortunately, with the Stemme,
that's pretty much a thing of the past.

On 8/1/2016 2:02 PM, Tango Eight wrote:
> Hi Dan,
>
> No, it wasn't a trick question (good one, Bob :-)), the answer is "the standard pattern".
>
> My $0.02: There's no science, no engineering, no product development going on, just traffic sequencing for landing.
>
> The standard pattern makes you predictable, adaptable within wide bounds, visible, unhurried. What's not to like? It's the perfect way to sequence.
>
> If you have the pattern to yourself (which is often the case where I mostly fly), then knock yourself out. There's the guy that can precision park the G-103 ride glider every time without using the wheel brake, the 2-33 pilot who likes his no-spoiler, no wheel brake precision landings and the XC hotshots doing their low passes in formation. I love that stuff. But when it's time to share with other traffic, particularly other traffic that includes student pilots, the best practice is a standard pattern.
>
> And yes, the glider handbook has some issues.
>
> best,
> Evan

--
Dan, 5J

[2G]

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 pissing 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

[NG]

Really, if you look at patterns that people actually fly, there is not so much difference in philosophy as you think. I challenge everybody to download log files from your airport, or contest, plot them, and see what they look like. Some base legs have long straight segments between sharp turns, some are merely connected gentle turns from downwind to final, but we all end up in the same place, on a controlled glide path and airspeed, safely aligned with the runway. The only thing that is confusing to students is authoritarian pronouncements of single and often incorrect ways to fly it. For example, nobody really flies downwind with a 45 degree lookdown angle to the runway, that would put them 800' away at 800 AGL, with no hope of flying a controlled base leg. Even the author of that silly guideline doesn't fly that close, if you look at his igc files at competitions. Most people fly downwind 2000-2500 away from the runway, which is more like a 20 degree lookdown angle. Do the math, look at what you actually fly, look at what other people fly. For example, see http://noss.ws/temp/patterns.jpg for a sampling of patterns a dozen or so experienced pilots flew and logged on OLC in varying conditions at the same location on the same runway.

[Squeaky]

'NG[_2_ Wrote:
> ;927571']Really, if you look at patterns that people actually fly, there

Now this part is true and very believable. I have seen this and when I
look at traces from others at my gliderport they are definitely twice as
wide (or wider) than I fly for my pattern. As previously mentioned,
being an ex USAF guy, and used to using angles to set up patterns for
bomb deliveries, I did try to do exactly what the books say, and at 1000
feet entering down wind I'd try to be at a 45 degree look down. By my
'rough' calculations (trig and all that), that means I'm on downwind
1000 feet away from the runway. Aint no one else at our glider port
that close...

I then check air brakes and leave them out in order to start getting
down and aim to hit abeam my touchdown point at a 30 degree look down
angle (from texts, 500' alt abeam touch down point, and trig again).
That position, rolling off downwind into a 25 degree bank rocks you
nicely around to final with a continuous not too hard turn, plenty of
correction, easy to see wind effect, roll out 1/4 mile aligned with
runway, simple.

I'm not sure who came up with the angles, but they either do not
understand trig, or did not do the calculations and compared them to
suggested altitudes at each point. As mentioned, since I see almost no
one else running down downwind at 1000 feet off set from the runway (and
usually at 2000') I'm pretty sure no one else is using that 45 degree
look down number.




--
Squeaky

[Dan Marotta]

Sorry I don't know your name, 2G, nor do I know where you fly, and I'm
not trying to get into a pissing 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

[wby0...@aol.com]

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.

[Bret Hess]

> We [British] divide the downwind to base turn into two approximately 45 degrees turns, to insert a 'diagonal leg'.

I'm going to give this a try. I don't like the "wait until the touchdown point is 45 degrees behind you before turning base" part of the square pattern training...I can't see the touchdown point then. This BGA method seems like better training for XC outlandings than a square pattern

[Tango Whisky]

Le mardi 2 août 2016 18:58:43 UTC+2, wby0...@aol.com a écrit :
>
> 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.

[BobW]

On 8/2/2016 10:58 AM, wby0...@aol.com 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.

[wby0...@aol.com]

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.

[Tango Whisky]

Le mardi 2 août 2016 22:07:26 UTC+2, wby0...@aol.com a écrit :
> 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.

[wby0...@aol.com]

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.

[soa...@gmail.com]

On Tuesday, August 2, 2016 at 3:03:43 PM UTC-7, wby0...@aol.com wrote:
> 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.

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. If you are going that slow, won't a sudden steep turn put you below the stall speed? And won't that cause you to fall rather quickly from the sky?

[resi...@sbcglobal.net]

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

[wby0...@aol.com]

Can we agree that stalling is directly related to angle of attack and secondarily related to airspeed?

[Tango Whisky]

Le mercredi 3 août 2016 01:43:20 UTC+2, wby0...@aol.com a écrit :
> Can we agree that stalling is directly related to angle of attack and secondarily related to airspeed?

Absolutely.
At moderate bank angles, say below 60 degree, all gliders I've flown so far do have enough elevator authority to stall them. As the g-loads increase with banking angle, the momentum created by one wing stalled and the other sill flying increases, so departure into spin will be more violent.

Now, if you moce the center of gravity forward, the you will limit the elevator authority needed to stall the glider. Seats are typically limited to 242 pounds due to the maximum allowable stress on the harness attachment points and exceedig this, you often can't stall the glider even with wings levelled. In trainers, this is more pronounced as part of the backseat load counts towards the effective load in the front seat (in a Duo, it's about one third). So, having two stately mammiferes on board will drastically increase spin resistance, and decrease the maximum bank angle where you can still stall the glider.

But the typical single seater glass ship flown within the CoG range defined by the manufacturer has no increased spin resistance whatsoever at bank angles used during pattern.

[Don Johnstone]

At 23:43 02 August 2016, wby0...@aol.com 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.

[cjlbo...@gmail.com]

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

[Squeaky]

BobW;927595 Wrote:
> On 8/2/2016 10:58 AM, wby0...@aol.com 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).-

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.




--
Squeaky

[wby0...@aol.com]

"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.

[Tango Whisky]

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

[wby0...@aol.com]

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

[Tango Eight]

On Wednesday, August 3, 2016 at 12:12:40 PM UTC-4, wby0...@aol.com 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

[soa...@gmail.com]

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.

[tkn...@earthlink.net]

Regarding the many ideas posted, it is probably fitting to repost the following:

"64% of fatal glider accidents occur during the landing phase."

Tom Knauff

[Don Johnstone]

That's a bit like saying that 99% of people who enter a retirement
home die there. You only have to get 30 seconds of any flight
absolutely right, the first and last 15 seconds, you can get away with
most everything else. You only crash when the ground gets in the way.

[Charlie M. (UH & 002 owner/pilot)]

True (for me....).

"Train for the worst, plan for the best".

I do a sorta standard 3 sided pattern, allowing for adjustments.
I will also allow students to get low on the "wrong side of the pattern" to see what they do.
At the end of tha day, are they OK, is the aircraft flyable?
If yes to both, that's a start, discuss from there.

Some here know where I've landed before, not happy on my end other than worst was a broken gear door hinge or grass stains......
I can teach from my "less than wonderful choices" in the past.
Do the "standard pattern" (at least in the US) most of the time so others can "guess" what you're doing.
Adjust as needed.
Be prepared for stupid stuff "weather, other pilots, ground peeps, etc......".

[wby0...@aol.com]

Or over speed, or over G, or collide with another aircraft, unintentional IMC, land long, land too fast...

[kirk.stant]

Then perhaps we are teaching it wrong?

Or not beating into new pilots' the deadly importance of AOA (or airspeed, for the unwashed...) when low and slow?

A landing pattern is just a procedure. When it becomes a crutch for poor airmanship (knowledge, skills, currency) it can apparently become pretty deadly!

Kirk
66

[NG]

Would you be happier if the distribution of fatal accidents favored some other phase of flight? The goal should be to reduce overall accidents, not to shift fatalities to some other phase of flight!

[Bruce Hoult]

More than that .. take students lowish (300 or 400 ft) downwind of the field or on the wrong side of the pattern (or both), or directly over the touchdown point (deliberately "thermalling" in sink works well) and then "you have control". If they can't sort it out with a non-standard circuit then they're not ready for solo.

[mdfa...@gmail.com]

An AOPA article states that the AOPA Safety Institute and University of North Dakota are studying the "circular vs rectangular" pattern as a result of the NTSB "Most Wanted Safety Improvements. It'll be interesting to see what the study produces.

[Dan Marotta]

To reply to the subject question in a word: NO.

You can stall and spin from any attitude or airspeed. All you have to
do is plan and execute it correctly or simply f*ck up the turn.

On 11/18/2016 6:25 AM, mdfa...@gmail.com wrote:
> An AOPA article states that the AOPA Safety Institute and University of North Dakota are studying the "circular vs rectangular" pattern as a result of the NTSB "Most Wanted Safety Improvements. It'll be interesting to see what the study produces.

--
Dan, 5J

[2G]

It's REALLY hard to spin while flying coordinated - if you know of a way I would truly like to know. It is also tough to stall while flying coordinated because it takes a very high angle of attack and you would really have to work it keeping the glider coordinated as you approach stall. The FAA is emphasizing an angle of attack indicator to prevent spins; I think what is needed is an audible flight coordination indicator. In our gliders we have a heads-up flight coordination indicator which is even better - it's called a yaw string (but you have to look at it and react to it).

Tom

[Bruce Hoult]

Define "coordinated". No problem to spin with the string perfectly centered.

It's true in any glider with enough elevator, but the Blanik is excellent for demonstrating it. Shallow turn, very graaaadually slow it down, maintaining constant bank angle with aileron and keeping the string in the middle with the rudder. Pretty soon you've got a whole heap of out of turn aileron and into turn rudder. But the string is in the middle and the nose isn't even very high. And then BAM full-on incipient spin.

[Martin Gregorie]

Sounds like something the Puchacz would also do rather well. Must try it
during my next annual check.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Dan Marotta]

My Stemme has built-in AoA indication but it's on the EFIS and I'm
looking outside during the pattern. All you really need is to be able
to recognize sloppy controls, reduced noise, and uncommanded movement of
the nose. This has been discussed to death (no pun intended). There's
no instrument that can protect you as well as training and practice and,
if you need to rely on an instrument, maybe you should be keeping
tropical fish instead of flying.

--
Dan, 5J

[2G]

I rely on my instruments EVERY time I fly, especially in the landing phase; don't you? Training and practice are a good thing, but they CAN'T substitute for good instruments, only teach us to use them properly. One can compensate for the loss of an instrument, like airspeed, but one would not deliberately not pay attention to a working ASI in the landing phase.

I, too, have an AOA; it is the artificial horizon in my Air Avionics (aka Butterfly) vario. I do not find it particularly helpful. I prefer to monitor the real-time wind indicator instead. I also assume that you pay attention to wind socks...

Tom

[2G]

You just confirmed what I said: it is very HARD to spin flying coordinated (not that it can't be done). You also have to ignore your other instruments, particularly the ASI.

Tom

[kirk.stant]

Link to the AOPA/UND landing pattern safety study:

https://www.aopa.org/news-and-media/all-news/2016/november/17/aopa-air-safety-institute-und-study-stabilized-approach

No doubt in my mind which is the safer way to fly a pattern - the one that doesn't require rolling into and out of several 90 turns at low altitude...

I hope they also evaluate the best way to enter a pattern - The beauty of using the overhead entry to downwind (See AIM for details) is that if you know the field elevation, an overhead pattern will always put you at the same place on downwind relative to your landing aim point, regardless of whether it's your home airfield or someplace you have never been before. Combined with a 180 turn to land, it makes arrivals and landings reliably repeatable and consistent - and safer, IMO (and apparently in the opinions of most militaries, etc...).

Looking at this image of experienced pilots landing (cribbed from a previous post, thanks!) http://noss.ws/temp/patterns.jpg, I see only ONE trace that is a classic square pattern, with a couple more that are a bit less angular. The rest seem to be more or less continual turns to final.

Kirk
66

[Dan Marotta]

AWOS before entering pattern
Wind sock, also before entering pattern
ASI occasionally
I can't think of anything else I need to fly a pattern.

When my wife was training in a G-103, a bug plugged the pitot tube. She
had no trouble flying the pattern without an ASI.

--
Dan, 5J

[Waveguru]

I pay more attention to my vario in the pattern than I do my ASI. The wind sock is probably the most important thing to be aware of when landing, everything else you can feel, hear, and see. It's very easy to miss that the wind has doubled since you took off.

Boggs

[SoaringXCellence]

Tom,

Is the Artificial Horizon really an AoA Indicator? If you hold a true nose-on-the-horizon in a glider, it will slow down and begin a descent, which means the AoA is increasing, but the nose still shows a 0 degree reference to the horizon. I've been teaching and flying instruments for 22 years and even in a power plane the Artificial Horizon almost never shows the Angle of attack.

Mike