Undershoot Vs. Overshoot airport landing accidents

[[email protected]]

I always assumed that there are more overshoot airport accidents than undershoot ones. That is mainly due to our general knowledge that it's better to be too high than not high enough.
Am I correct here ?
Dan

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

I will say for more than 40 years flying sailplanes (and some power) undershoots are more common at an airport.
Offfield, I would guess more like 50/50........

My common thing in the beginning of the flying season.....get current, then do several "hang all the crap out from high on final!" To see what it looks like.
This could be a SGS-xxx to a ASW-20A or C (which come down like homesick bricks when pushed).

As in other disciplines, "train for the worst, hope for the best!"

Yes, 8 years as a CFIG, did a lot more basic through XC training.
Some here know where I have landed before with no more than grass stains.

[Mike the Strike]

On Wednesday, April 17, 2019 at 8:28:44 AM UTC-7, wrote:
> I always assumed that there are more overshoot airport accidents than undershoot ones. That is mainly due to our general knowledge that it's better to be too high than not high enough.
> Am I correct here ?
> Dan

In 50+ years of soaring, I've only ever seen one overshoot - a pilot mistook the flap handle for the spoiler and flew the whole length of the runway with full flaps and no spoilers. I've seen plenty come short, including two hitting wire fences at the beginning of a mile-long runway! Modern sailplanes can dump altitude spectacularly - I have turned from base to final at 1,000 feet and still made a descent to the proper end of the runway. Wind shear and unexpected sink in the pattern can ruin your day!

Mike

[Ramy[_2_]]

Overshoots are more likely in small field landouts. Undershoots are more likely in airports due to low patterns.

Ramy

[Steve Leonard[_2_]]

On Wednesday, April 17, 2019 at 3:51:44 PM UTC-5, Ramy wrote:
> Overshoots are more likely in small field landouts. Undershoots are more likely in airports due to low patterns.
>
> Ramy

Unless you are flying an AS-W12. I heard a story from a very well know pilot that he had been given the advice on slipping the 12 to landing of "don't take it out of the slip early, as it will float forever. It will even float further than you think it might if you take it out of the slip when you are afraid of spearing the wingtip into the ground." So, he slipped for all he was worth, took it back to straight, and landed short of the runway!

But in general, yes. I have seen people fly low patterns far more often than I have seen someone land long. And I have seen people be praised after a low pattern, never touching the dive brakes, and floating in ground effect for an incredible distance to make it to the desired stopping place.

Steve Leonard

[BobW]

On 4/17/2019 2:51 PM, Ramy wrote:
> Overshoots are more likely in small field landouts. Undershoots are more
> likely in airports due to low patterns.
>

Likely generally true, IMO, and to anecdotally expand a bit...

Home-field anecdotes - I know of (did not see) exactly one OVERshoot (defined
as 'overshooting the runway' and NOT merely the intended aiming point) on my
home field post-'1977: L-13; pilot ended up with a strand of barbed wire taut
across his throat after heaving mightily on the flaps handle (thinking it was
the spoiler handle) until stopped by the fence. OTOH I've seen multiple (as
in, WAY too numerous to count) low-patterns, including one that ended in the
small lake off the west end of the most-commonly-used runway, another that
('safely') clipped a tree on final, and one (mine, I'm embarrassed to note)
that *almost* ended in the lake due to slightly misjudging a short-field,
full-HP-14-flaps, practice-approach to the actual runway threshold located
perhaps 200' beyond the end of the lake. At least I stopped ON the runway (by
about a fuselage length)...and thereafter never-again practiced short-field
landings with a zero-margin aiming point. (Duh!)

Off-field opinionating - It's - again, IMO - 'fairly common' for newbies and
those lacking 'much' off-field landing experience to fly in-too-tight downwind
legs (evidently 'feels safer'?) to ultimately end up high on final...which has
'the usual expected results' if the field they're aiming for is (in their
estimation) a short one. A buddy totaled his PIK-20B by overshooting a
shortish field in the mountains. Per his recounting, he made 3 fundamental
errors: 1) downwind final (!); 2) high/tight downwind (no surprise to me); 3)
5+ knots of 'safety speed' throughout the pattern (for the wife and
kiddies...but inappropriate under the circumstances). He was fortunate to not
be injured. His post-mortem concluded the field was of sufficient length for a
properly flown/executed approach/pattern/flare to a reasonable aiming
point...IOW it definitely did NOT require 'all-out pilot-proficiency' as a
chosen field.

I'll bet Real Money 'foolishly low approaches' are wincingly common at the
vast majority of USA gliderports, based on decades of critiquing 'em at many a
field as an interested, bystanding, soaring nut.

Bob W.

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[Z Goudie[_2_]]

Confucius he say "Better the far fence at 15kts than the one on approach at
stall speed".

[[email protected]]

2 years ago our club (Soaring Club of Houston) invited a speaker from the Soaring Safety Foundation to speak at our club's annual safety meeting. Part of that presentation included a discussion on how to more effectively scrub excess altitude. The procedure is simple. Extend full airbrakes and then push the nose over to speed up. The drag is exponential to airspeed so a 15-20 knot increase in airspeed generates a tremendous sink rate. No need to slip.

A bit later that spring another SCOH pilot asked me to fly with him for a couple pattern tows so I had the opportunity to teach and video from the back seat. In the link that follows we're in a ASK-21 at 900 ft AGL on base and using the described procedure it only required speeding up to 80 knots to reach the approach end of the runway and use less than 1,000 ft to stop.

My take away from the lecture and this procedure is that it's always better to be on the high side.

https://www.youtube.com/watch?v=DE61D5QJHZE&feature=share

[Tango Whisky]

Le jeudi 18 avril 2019 14:17:40 UTC+2, a écritÂ*:
> 2 years ago our club (Soaring Club of Houston) invited a speaker from the Soaring Safety Foundation to speak at our club's annual safety meeting. Part of that presentation included a discussion on how to more effectively scrub excess altitude. The procedure is simple. Extend full airbrakes and then push the nose over to speed up. The drag is exponential to airspeed so a 15-20 knot increase in airspeed generates a tremendous sink rate. No need to slip.
>
> A bit later that spring another SCOH pilot asked me to fly with him for a couple pattern tows so I had the opportunity to teach and video from the back seat. In the link that follows we're in a ASK-21 at 900 ft AGL on base and using the described procedure it only required speeding up to 80 knots to reach the approach end of the runway and use less than 1,000 ft to stop..
>
> My take away from the lecture and this procedure is that it's always better to be on the high side.
>
> https://www.youtube.com/watch?v=DE61D5QJHZE&feature=share

Go and try that with a DuoDiscus.

Bert TW

[Steve Leonard[_2_]]

On Thursday, April 18, 2019 at 8:12:20 AM UTC-5, Tango Whisky wrote:
>
> Go and try that with a DuoDiscus.
>
> Bert TW

But, only on a runway that is clear off the departure end. Because you will depart, right, Bert?

Steve Leonard

[Tango Whisky]

Le jeudi 18 avril 2019 15:36:08 UTC+2, Steve Leonard a écritÂ*:
> On Thursday, April 18, 2019 at 8:12:20 AM UTC-5, Tango Whisky wrote:
> >
> > Go and try that with a DuoDiscus.
> >
> > Bert TW
>
> But, only on a runway that is clear off the departure end. Because you will depart, right, Bert?
>
> Steve Leonard

Well, you will float over the runway forever.
I always prefer a slip (which works extremely well in both ASK21 and DuoDiscus) - no change of attitude, and dosage is much easier.

But in the end, I prefer to train people to do a proper approach pattern, where you end up un final with 50% airbrakes.

[Tim Taylor]

Please don't teach the dive to lose altitude technique. The problem is total energy, simply the kinetic plus potential energy. Most pilots are trained with judgment on altitude (potential energy) but have poor judgment how speed (kinetic energy) will impact touch down point and speed. Our brains are much better at doing estimates with constant speed. Yes, it is a neat trick to dive at the ground but has a higher probably for error than simpler techniques. See the article in soaring about the pilot that flew off the end of the runway. If you are really high, 500 to 1000 feet agl, the glider polar works both ways around the best l/d, rather than speeding up it is better to slow down and use full spoilers and a slip. I have modeled both techniques and the achieved l/d over the ground is just as low with the slower technique and there is no speed to scrub once you are back in correct height band for the approach. If you are really high, slow down to near stall speed, use full spoilers and slip. As you get lower (about 400 feet agl) accelerate to normal approach speed for the conditions.

Even better is to teach students to be flexible and not get fixated on completing a traditional pattern, S-turns or a 360 if a pilot is really too high are better options.

[Andreas Maurer[_2_]]

On Thu, 18 Apr 2019 07:00:39 -0700 (PDT), Tango Whisky
> wrote:

Steve Leonard
>
>Well, you will float over the runway forever.
>I always prefer a slip (which works extremely well in both ASK21 and DuoDiscus) - no change of attitude, and dosage is much easier.

100% agree.

>
>But in the end, I prefer to train people to do a proper approach pattern, where you end up un final with 50% airbrakes.

.... not to mention that precise speed control is the thing that
counts.

It is absolutely necessary in an outlanduing, and in my humble opinion
ought to be trained in any landing, even if there''s a 6.000 ft
runway.

Cheers
Andreas

[Tango Eight]

On Thursday, April 18, 2019 at 10:47:26 AM UTC-4, Tim Taylor wrote:
> Please don't teach the dive to lose altitude technique. The problem is total energy, simply the kinetic plus potential energy. Most pilots are trained with judgment on altitude (potential energy) but have poor judgment how speed (kinetic energy) will impact touch down point and speed. Our brains are much better at doing estimates with constant speed. Yes, it is a neat trick to dive at the ground but has a higher probably for error than simpler techniques. See the article in soaring about the pilot that flew off the end of the runway. If you are really high, 500 to 1000 feet agl, the glider polar works both ways around the best l/d, rather than speeding up it is better to slow down and use full spoilers and a slip. I have modeled both techniques and the achieved l/d over the ground is just as low with the slower technique and there is no speed to scrub once you are back in correct height band for the approach. If you are really high, slow down to near stall speed, use full spoilers and slip. As you get lower (about 400 feet agl) accelerate to normal approach speed for the conditions.
>
> Even better is to teach students to be flexible and not get fixated on completing a traditional pattern, S-turns or a 360 if a pilot is really too high are better options.

No 360s please. That has disaster written all over it.

Kai Gersten introduced me to the "reversed base leg" approach years ago. This works great, it's easy to fly, easy to teach and the technique is the same in any glider. You extend the (too high) base leg past the runway centerline some appropriate distance, make a 180 (turn towards the runway), make a second base leg from the other side of the runway.

I've experimented with S-turns (after reading George Moffatt). They work well. I was able to turn a much too high approach into a spot landing twice in two tries. Glider folk on the ground won't enjoy this, they'll think something is wrong.

best,
Evan Ludeman / T8

[[email protected]]

> I've experimented with S-turns (after reading George Moffatt). They work well. I was able to turn a much too high approach into a spot landing twice in two tries. Glider folk on the ground won't enjoy this, they'll think something is wrong.
>
> best,
> Evan Ludeman / T8

Yeah, S-turns work well. They were part of our curriculum 50+ years ago but I"m not sure how many U.S. pilots have experience with them now. I've used them at the airport and going into fields. At the airport, they can confuse folks on the ground and, especially, others in the pattern. But MUCH preferable to a 360 once you're down to pattern altitude.

I like coming in fairly high with plenty of airspeed. I can always get rid of it. Diving it off works but, as Tim observes, can be deceptive. I love slips.

Chip Bearden
JB

[[email protected]]

Bert, Would you accept an Arcus vs a Duo?

[Mike the Strike]

On Thursday, April 18, 2019 at 7:47:26 AM UTC-7, Tim Taylor wrote:
> Please don't teach the dive to lose altitude technique. The problem is total energy, simply the kinetic plus potential energy. Most pilots are trained with judgment on altitude (potential energy) but have poor judgment how speed (kinetic energy) will impact touch down point and speed. Our brains are much better at doing estimates with constant speed. Yes, it is a neat trick to dive at the ground but has a higher probably for error than simpler techniques. See the article in soaring about the pilot that flew off the end of the runway. If you are really high, 500 to 1000 feet agl, the glider polar works both ways around the best l/d, rather than speeding up it is better to slow down and use full spoilers and a slip. I have modeled both techniques and the achieved l/d over the ground is just as low with the slower technique and there is no speed to scrub once you are back in correct height band for the approach. If you are really high, slow down to near stall speed, use full spoilers and slip. As you get lower (about 400 feet agl) accelerate to normal approach speed for the conditions.
>
> Even better is to teach students to be flexible and not get fixated on completing a traditional pattern, S-turns or a 360 if a pilot is really too high are better options.

I've been playing with the high base approach lately as it was suggested by a visiting instructor and was also taught to me at a British glider site that suffers from bad rotor (a traditional approach at that site on a breezy day would have you whack into a stone wall well short of the runway!).

Many gliders handle the high speed descent very well - 70+ knots and full spoilers. I find the PW-6 is a delight in this approach and slowing down at landing quite natural. Some other gliders not so much! A colleague suggests that the Grob 103 prefers slower speeds where its sink rate is also quite high. Soaring pilots should be familiar with all landing approaches at their disposal and use the appropriate one for their glider and site conditions.

Far more pilots end up short through insufficient height or low energy than the reverse - the only two observations in this thread about overshooting a home field were pilots who mistook the flap handle for spoiler! I know of one outlanding overshoot in which the pilot deliberately flew across a huge field in an attempt to finish close to the gate and overran into a hedge..

Mike

[George Haeh]

Drag increases with the square of the airspeed (not exponentially).

So increasing airspeed from 55 to 70 increases drag by 62%.

Judgement is needed in round out.

Our Grob 103 can get frisky close to the ground with extra speed, single panel spoilers and one pilot. Older two seat trainers tend to have lots of wing area and small spoilers; so, you can go a long way in ground effect.

But no problem when your aim point is the threshold - much more interesting on hangar landings.

Kinetic energy remains constant with constant airspeed. On final we are using drag to dissipate potential energy instead of allowing it to convert to kinetic energy.

[Bob Whelan[_3_]]

On 4/18/2019 9:13 AM, Tango Eight wrote:
> On Thursday, April 18, 2019 at 10:47:26 AM UTC-4, Tim Taylor wrote:
>> Please don't teach the dive to lose altitude technique. The problem is
>> total energy, simply the kinetic plus potential energy. Most pilots are
>> trained with judgment on altitude (potential energy) but have poor
>> judgment how speed (kinetic energy) will impact touch down point and
>> speed. Our brains are much better at doing estimates with constant
>> speed. Yes, it is a neat trick to dive at the ground but has a higher
>> probably for error than simpler techniques. See the article in soaring
>> about the pilot that flew off the end of the runway. If you are really
>> high, 500 to 1000 feet agl, the glider polar works both ways around the
>> best l/d, rather than speeding up it is better to slow down and use full
>> spoilers and a slip. I have modeled both techniques and the achieved l/d
>> over the ground is just as low with the slower technique and there is no
>> speed to scrub once you are back in correct height band for the approach.
>> If you are really high, slow down to near stall speed, use full spoilers
>> and slip. As you get lower (about 400 feet agl) accelerate to normal
>> approach speed for the conditions.
>>
>> Even better is to teach students to be flexible and not get fixated on
>> completing a traditional pattern, S-turns or a 360 if a pilot is really
>> too high are better options.
>
> No 360s please. That has disaster written all over it.
>
> Kai Gertsen introduced me to the "reversed base leg" approach years ago.
> This works great, it's easy to fly, easy to teach and the technique is the
> same in any glider. You extend the (too high) base leg past the runway
> centerline some appropriate distance, make a 180 (turn towards the runway),
> make a second base leg from the other side of the runway.
>
> I've experimented with S-turns (after reading George Moffatt). They work
> well. I was able to turn a much too high approach into a spot landing
> twice in two tries. Glider folk on the ground won't enjoy this, they'll
> think something is wrong.

Apologies for 'going further off into the weeds' here - at least relative to
the OP's explicit original question - but this is the sort of discussion I: 1)
find personally interesting, because 2) it touches upon 'stuff' that every
'serious' gliderpilot likely also finds interesting. I'm defining 'serious' in
this context as every Joe Glider Pilot interested in preservation of
self/glider for another fun flight tomorrow, regardless of whether it's to
sit-on-the-flagpole or go XC or whatever...

If JGP has somehow botched a pattern to the point he's 'uncomfortably high' on
final - and haven't we all done so for various reasons, ranging from
intentional practice, to unexpected serious/sustained lift on base or final,
to 'something(s) else' - he'll be faced with 'What to do about it to safely
salvage the situation?'

FWIW, I'm not a believer in 'specific rules of thumb that are always 100%
correct/applicable,' but am more a 'fundamentalist thinker.' In high-final
terms, I fall into the category that believes salvation is most likely safely
accomplishable for Joe Average Glider Pilot (me!) by avoiding - as far as
'reasonably possible' - edging into Joe Test Pilot territory. I put 360's on
final into the JTP category, for example...*somewhat* akin to 'practicing
departure-from-controlled-flight in the pattern,' in the sense that the
potential 'good return' isn't worth the unavoidably-accepted 'in-flight risk.'
("Hey! Lemme practice turning my back on the field at the last minute; it
seems like a good idea just because it flashed into my mind as 'salvation.'
Woohoo!")

At my specific home field (Boulder, CO), doing so would also guarantee either
crossing (twice!) through a parallel power-plane-runway's final approach, or
(again, twice) 'somewhat below' the glider pattern's final/base legs. Not so
wise in my book, regardless of the 'wisdom' (Not!) of turning one's back on
one's intended touchdown area.

Those times I (intentionally, mostly, but rarely, unintentionally) found
myself 'WAY too high on shortish final approach' at Boulder I opted either for
landing long (once convinced it was safely possible) or,(seriously considered,
but never actually required) S-turning along final to lengthen the final's
flightpath length. The latter was always Option 2, in a preferred sense, for
the reasons Tango Eight alludes to. (It's bad enough to alarm myself; no need
to go out of my way to alarm other pilots who may be sharing nearby airspace!
Ground-pounders? Worry about 'em later...)

I rejected the 'dive-n-drag' approach (commonly used 'for fun' at one time by
the gliding FBO's ride pilots in their 2-32s 'just because hey could') cuz I
never ended up 'ridiculously high' in a spoilered ship, only in (my own)
large-deflection-landing-flapped ships, and if there's a *second* situation
such ships don't handle particularly gracefully (the first being low, slow,
and short), it's being in ground-effect with excess speed and full flaps.
(Kids, can you spell: F - L - O - A - T ???)

WRT off-field approaches, both the S-turning option and the 'extended/reversed
base leg seem 'eminently-safely-usable' to me, without 'messing about with'
(for the first time, likely, for many) the suddenly-increasing-kinetic-energy
playground associated with a diving-final-approach. (Best to avoid JTP-land,
again...)

YMMV, of course.

Bob W.

P.S. I believe it's GOOD (for JGP) to seriously consider, and 'safely practice
this sort of stuff' by way of self-education and preparation for their own,
personal 'Reality Show!'

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[ProfJ]

On Wednesday, 17 April 2019 09:28:44 UTC-6, wrote:
> I always assumed that there are more overshoot airport accidents than undershoot ones. That is mainly due to our general knowledge that it's better to be too high than not high enough.
> Am I correct here ?
> Dan

Some good take-homes here that are generally true:

1. You are more likely to err and land short on airport landings.
2. You are more likely to err and land long or with too much energy on outlandings.
3. You can dump more energy with drag at high speed BUT...
4. This is very glider-dependent (i.t.o. your state at the threshold of runway)
5. Lengthening your glide path safely is easy BUT...
6. Not that easy to practice, depends on your home site.

[Piet Barber]

> Go and try that with a DuoDiscus.
>

Pfft.

https://youtu.be/Yc-oTfr5Zwc?t=525

[[email protected][_2_]]

‘No 360s please. That has disaster written all over it.’ T8

Disagree once the pilot is proficient and not a student. I consider a 360 circling pattern to an off field landing preferable, especially when field elevation is unsure.
S K makes a mistake, to ‘Preach’ to him not to use a proven technique to improve knowledge of the field condition because some can’t make a coordinated turn below 1000’ agl a bit of snake handling.

R

[Tango Eight]

On Thursday, April 18, 2019 at 2:43:00 PM UTC-4, wrote:
> ‘No 360s please. That has disaster written all over it.’ T8
>
> Disagree once the pilot is proficient and not a student. I consider a 360 circling pattern to an off field landing preferable, especially when field elevation is unsure.
> S K makes a mistake, to ‘Preach’ to him not to use a proven technique to improve knowledge of the field condition because some can’t make a coordinated turn below 1000’ agl a bit of snake handling.
>
> R

Hi Henry:

There's nothing wrong with a 360 degree pattern (that is, one that completely encloses the landing area). The 360 I am taking issue with is the tight 360 that happens on final because the pilot thinks he's hopelessly high. As previously noted, better solutions exist.

best,
Evan

[Tango Whisky]

Yes. Anytime.

[Tango Whisky]

What's your point? That was an easy situation.
How about you're too high on a field 700 ft long? 750 ft is about what I can expect as a field where I fly. And I've got away with 300 ft.

Bert TW

[Paul Agnew]

Lots of great insight to digest...Dive and Drag is an interesting solution, if you have enough runway to scrub off the excess speed and/or your spoilers are effective. My ASW19 stock spoilers are just not effective enough for me to try the Dive and Drag method.

Reverse Base Method = 180° turn to reverse + 90° turn to final = 270° (two turns & wind corrections).

Why not just make a stable, descending 270° turn when crossing the final? In powered, fixed-wing aircraft, it's not unusual to get assigned a right or left 270 to final by tower to improve spacing on departing aircraft. It's a basic ground reference maneuver that could be adapted for gliders so you roll out aligned with the runway.

We're supposed to be able to turn back to land above 200ft with a rope break, which is based on our collective understanding that we can safely execute a turn, maintain speed, and align with the runway from that minimum altitude. That requires 180° of turn, if the towplane drifted downwind and you turn into the wind (ideal, but our guys don't). Or, 210-270° total if you have to reverse course, angle for the runway, then turn back to align with the runway. The second scenario requires multiple, low-altitude turns. Is that ideal?

Performing a stable, 270° or 360° turn for altitude correction should be within out skillset, but only if the excessive altitude is above a certain threshold for your ship. 100-200ft high? Maybe not the best option. Clear knowledge of your ship's descent rate in a turn is critical for decision making.

That said, I've always been successful with a little slip to correct for any excess altitude. Starting the correction on the base leg and performing a slipping turn to final burns off a lot of excess altitude. (I learned to do this with Phil Beale on my CFI-A checkride back in 1986.)

Paul A.
Jupiter, FL

[Jonathon May]

At 21:14 18 April 2019, Paul Agnew wrote:
>Lots of great insight to digest...Dive and Drag is an interesting
>solution,=
> if you have enough runway to scrub off the excess speed
and/or your
>spoile=
>rs are effective. My ASW19 stock spoilers are just not effective
enough
>for=
> me to try the Dive and Drag method.=20
>
>Reverse Base Method =3D 180=C2=B0 turn to reverse +
90=C2=B0 turn to final
>=
>=3D 270=C2=B0 (two turns & wind corrections).
>
>Why not just make a stable, descending 270=C2=B0 turn when
crossing the
>fin=
>al? In powered, fixed-wing aircraft, it's not unusual to get
assigned a
>ri=
>ght or left 270 to final by tower to improve spacing on departing
>aircraft.=
> It's a basic ground reference maneuver that could be adapted
for gliders
>s=
>o you roll out aligned with the runway.
>
>We're supposed to be able to turn back to land above 200ft with
a rope
>brea=
>k, which is based on our collective understanding that we can
safely
>execut=
>e a turn, maintain speed, and align with the runway from that
minimum
>altit=
>ude. That requires 180=C2=B0 of turn, if the towplane drifted
downwind and
>=
>you turn into the wind (ideal, but our guys don't). Or, 210-
270=C2=B0
>total=
> if you have to reverse course, angle for the runway, then turn
back to
>ali=
>gn with the runway. The second scenario requires multiple, low-
altitude
>tur=
>ns. Is that ideal?=20
>
>Performing a stable, 270=C2=B0 or 360=C2=B0 turn for
altitude correction
>sh=
>ould be within out skillset, but only if the excessive altitude is
above a
>=
>certain threshold for your ship. 100-200ft high? Maybe not the
best
>option.=
> Clear knowledge of your ship's descent rate in a turn is critical
for
>deci=
>sion making. =20
>
>That said, I've always been successful with a little slip to correct
for
>an=
>y excess altitude. Starting the correction on the base leg and
performing
>a=
> slipping turn to final burns off a lot of excess altitude. (I
learned to
>d=
>o this with Phil Beale on my CFI-A checkride back in 1986.)=20
>
>Paul A.
>Jupiter, FL


When we flew K7 and K13 you could dive against the brakes,
provided you open the air brakes about 50kn then lowered the
nose the speed gain was not too high.If you put on 70Kn then
opened the airbrakes the speed would not reduce much.
However if you try that in a Mk 1 Duo discus you will be zooming
down the runway at 120+kn waiting for the boundary fence.

[Matt Herron Jr.]

On Thursday, April 18, 2019 at 11:54:32 AM UTC-7, Tango Eight wrote:
> On Thursday, April 18, 2019 at 2:43:00 PM UTC-4, wrote:
> > ‘No 360s please. That has disaster written all over it.’ T8
> >
> > Disagree once the pilot is proficient and not a student. I consider a 360 circling pattern to an off field landing preferable, especially when field elevation is unsure.
> > S K makes a mistake, to ‘Preach’ to him not to use a proven technique to improve knowledge of the field condition because some can’t make a coordinated turn below 1000’ agl a bit of snake handling.
> >
> > R
>
> Hi Henry:
>
> There's nothing wrong with a 360 degree pattern (that is, one that completely encloses the landing area). The 360 I am taking issue with is the tight 360 that happens on final because the pilot thinks he's hopelessly high. As previously noted, better solutions exist.
>
> best,
> Evan

Tight 360s are much safer than shallow 360s. Much harder to stall/spin. I just finished a winch launching class, and was taught that in the event of a rope break you can find yourself at mid field at 300' -400' and your best option is a tight 360 turn or two- to the downwind side, tangent to the runway, then land from mid field once below 300'. (this is for a shorter 2700' runway). It seemed very unintuitive at first, but it worked just fine.

[Dave Nadler]

On Thursday, April 18, 2019 at 5:14:05 PM UTC-4, Paul Agnew wrote:
> ...My ASW19 stock spoilers are just not effective enough...

Yup, do the -19 spoiler upgrade that adds an additional panel,
nice to have that additional drag and safety margin!

[Tango Eight]

On Thursday, April 18, 2019 at 6:33:47 PM UTC-4, Matt Herron Jr. wrote:
> On Thursday, April 18, 2019 at 11:54:32 AM UTC-7, Tango Eight wrote:
> > On Thursday, April 18, 2019 at 2:43:00 PM UTC-4, wrote:
> > > ‘No 360s please. That has disaster written all over it.’ T8
> > >
> > > Disagree once the pilot is proficient and not a student. I consider a 360 circling pattern to an off field landing preferable, especially when field elevation is unsure.
> > > S K makes a mistake, to ‘Preach’ to him not to use a proven technique to improve knowledge of the field condition because some can’t make a coordinated turn below 1000’ agl a bit of snake handling.
> > >
> > > R
> >
> > Hi Henry:
> >
> > There's nothing wrong with a 360 degree pattern (that is, one that completely encloses the landing area). The 360 I am taking issue with is the tight 360 that happens on final because the pilot thinks he's hopelessly high. As previously noted, better solutions exist.
> >
> > best,
> > Evan
>
> Tight 360s are much safer than shallow 360s. Much harder to stall/spin. I just finished a winch launching class, and was taught that in the event of a rope break you can find yourself at mid field at 300' -400' and your best option is a tight 360 turn or two- to the downwind side, tangent to the runway, then land from mid field once below 300'. (this is for a shorter 2700' runway). It seemed very unintuitive at first, but it worked just fine..

Thanks for pointing that out. Winch training on my todo list, maybe I'll change my opinion in light of new data. Winch trained pilots have some advantages: namely, a lot more landings and more low altitude maneuvering and decision making. That's got to make a difference.

-Evan

[Paul Agnew]

On Thursday, April 18, 2019 at 7:16:56 PM UTC-4, Dave Nadler wrote:
> On Thursday, April 18, 2019 at 5:14:05 PM UTC-4, Paul Agnew wrote:
> > ...My ASW19 stock spoilers are just not effective enough...
>
> Yup, do the -19 spoiler upgrade that adds an additional panel,
> nice to have that additional drag and safety margin!

It's on the wish list along with the lift up binacle and disc brake mod. There's nobody in our area that is familiar with gliders enough to engage them for the spoiler mod.

PA

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

OK......a reply down the thread.......

Chewing on this a bit........

My basic comment.....if you are rusty enough to totally blow a pattern, I think you are rusty enough to NOT do a 360 late in the pattern.....

I basically have NO issues with doing a 360* pattern approach (sorta common for US aviation military) or current GA pilots......
Being "OMG" high for a non-current pilot (ANY kind) on final.....you have already sorta proved you are rusty...thus you are adding to that by doing a 360 on final.......
Can we say "another statistic"?!?!?!

Part of me states.......complacency.......
Good example?
The Snowbird at HHSC every fall.
Some peeps do well.
Others "have to practice".......!!!!
Why?
The basics are......energy management in a known environment.
What is the issue?

Go look up the rules for the HHSC Snowbird rules......anybody doing XC should do well in the comp......sheesh......anybody close to PPG or above should do well.....power guys should be close....
I have seen too many peeps used to, "Land somewhere, peeps will push us back...." is total BS....!!!!
Every landing is to a point, end up where you need to be........
Period......

Yes......poop happens, way too many "stupid broken stuff" based on complacency.......
Yes, I help fix some "stupid stuff"...,,,,,

Yes, I agree with T8 and some others here.
I have stated some of what I do/recommend.
I will assume some peeps here think I am a "butthead" which may be true (for various reasons.....) but worst I have done in decades is pull glass gear door rivets in sorta tall crop p,us lots of grass stains.
I have no clue on how many off airport landings I have done from 1-26 to ASG-29.

OK.....let the poop storm start....I have my Nomex suit on....I don't care other than......
Don't hurt the ship.....peeps are OK.
Period.

[son_of_flubber]

This thread reminds me of 'a friend of mine' who set his altimeter to exactly 1000 feet lower than field elevation.

Then he took a long and high flight in wave and had gotten used to 'things look tiny on the ground', so he was on downwind before he got the That Looks About Wrong rude awakening.

[David Salmon[_3_]]

At 15:28 17 April 2019, wrote:
>I always assumed that there are more overshoot airport accidents than
>undershoot ones. That is mainly due to our general knowledge that it's
>better to be too high than not high enough.
>Am I correct here ?
>Dan
>

I once saw a pilot fly the full length of a 1000yd grass airfield, then do
a 180 and fly all the way back, try another 180 until the wingtip hit, and
crash, all the while with the wheel going up and down. Fortunately just a
bent glider, no injury.
Dave

[Eric Greenwell[_4_]]

Matt Herron Jr. wrote on 4/18/2019 3:33 PM:

> Tight 360s are much safer than shallow 360s. Much harder to stall/spin. I just finished a winch launching class, and was taught that in the event of a rope break you can find yourself at mid field at 300' -400' and your best option is a tight 360 turn or two- to the downwind side, tangent to the runway, then land from mid field once below 300'. (this is for a shorter 2700' runway). It seemed very unintuitive at first, but it worked just fine.

Why not turn 180, fly downwind, and then do another 180 when you have enough
runway to land, instead a tight 360? And especially instead doing two 360's!


--
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

[[email protected]]

On Thursday, April 18, 2019 at 2:05:10 PM UTC-5, Tango Whisky wrote:
> Yes. Anytime.

This isn't intended to come across as a "I told you so", but educational for those who predicted that a steep full spoiler approach will put you into the far fence at high speed.

Arcus M, 1650 lbs. starting out close to the same spot as the first video and also 1,200 ft MSL (field elevation 300) and I had to close spoilers almost fully to clear the 20' high power lines on the approach end of the "extension" at SCOH. I adjusted pitch just a tad and ballooned before touchdown but total distance over the 20' wires was approximately 1,400 ft and without significant braking my landing roll was on the order of 700-800ft per Google Earth.

I will try this again, but starting much higher and post again. With full spoilers and modest increase in airspeed you can scrub a lot of altitude. Recommended to be tested at altitude first.

Video at the following link:

https://youtu.be/2-KiGtSbkMA

Mark

[Tango Whisky]

The Arcus is a completely different ship and has decent airbrakes. The Duodiscus hasn't.

[Jonathon May]

At 04:43 23 April 2019, Tango Whisky wrote:
>The Arcus is a completely different ship and has decent
airbrakes. The
>Duodiscus hasn't.
>
The Duo discus didn't but
The Duo Discus XL has excellent brakes and has been around 10
years now.
The Arcus is more like the XL

[Delta8]

Well ? If one has wings level with spoilers deployed and is anticipated running out of runway why not throw left and right rudder to skid ?

[[email protected]]

I just want to underscribe the statement:
Don't Ever Do the Airbrake Dive in the DuoDiscus Mk 1.
It won't have the desired effect, while actually bringing the sailplane in ground effect at very high speeds. Unless you have 3 km or more of runway in front of you.
The 2nd generation of the Duo (with landing flaps) allows this technique. The Arcus has powerful drag devices. Totally different beasts when managing the energy for landing.

Been there, done that, had vertebrae concussion and a nerve compression.

Aldo Cernezzi
www.voloavela.it

[[email protected]]

A. The only Duo on our field sold recently so I don’t have access to one for testing.

B. If you watch both videos it can be readily observed that the steep approach is discontinued well before reaching ground effect. Both flights crossed the airport threshold at a nominal airspeed. One must scrub altitude early enough to get back to a stable approach before touchdown.

Having previously owned a Duo T (pre-XL) I’m pretty confident that this technique will be similarly effective, but don’t have the means to make that video at this time.

[2G]

On Tuesday, April 23, 2019 at 6:11:25 AM UTC-7, wrote:
> A. The only Duo on our field sold recently so I don’t have access to one for testing.
>
> B. If you watch both videos it can be readily observed that the steep approach is discontinued well before reaching ground effect. Both flights crossed the airport threshold at a nominal airspeed. One must scrub altitude early enough to get back to a stable approach before touchdown.
>
> Having previously owned a Duo T (pre-XL) I’m pretty confident that this technique will be similarly effective, but don’t have the means to make that video at this time.

An over-shoot landing accident isn't about fine-tuning technique: the pilot has simply become a passenger and has stopped flying the glider. The question is: why does someone who has passed the necessary demonstration of proficiency all of a suddenly enters into an out-of-body state of mind? I don't know and I don't know how to predict it.

Tom

[Dan Marotta]

Just because the certificate says "Pilot" does not mean the holder is
truly a pilot.Â* A monkey can be trained to perform the required
maneuvers, but not to extend to untrained situations.Â* I know just such
a man.Â* Fortunately for him and the sport.Â* He stopped flying.

On 4/24/2019 9:25 PM, 2G wrote:
> On Tuesday, April 23, 2019 at 6:11:25 AM UTC-7, wrote:
>> A. The only Duo on our field sold recently so I don’t have access to one for testing.
>>
>> B. If you watch both videos it can be readily observed that the steep approach is discontinued well before reaching ground effect. Both flights crossed the airport threshold at a nominal airspeed. One must scrub altitude early enough to get back to a stable approach before touchdown.
>>
>> Having previously owned a Duo T (pre-XL) I’m pretty confident that this technique will be similarly effective, but don’t have the means to make that video at this time.
> An over-shoot landing accident isn't about fine-tuning technique: the pilot has simply become a passenger and has stopped flying the glider. The question is: why does someone who has passed the necessary demonstration of proficiency all of a suddenly enters into an out-of-body state of mind? I don't know and I don't know how to predict it.
>
> Tom

--
Dan, 5J

[Charlie Quebec]

I was taught to always judge my circuit by the angles, and to do so with no instruments, so I’ve never been in a bad position on final.
What on earth do you do in the US that leads to the need for s turns, 360s etc?
In my winch training, I did several highly modified full circuits from 400ft with ease.

[ripacheco1967]

High is better...
https://youtu.be/z66osZ4ri5A

[Dan Marotta]

A poorly planned approach and a well executed slip.Â* Why do you ask
about what we do in the US when this is clearly German?

I agree with you on judging patterns with angles rather than instruments.

On 4/27/2019 11:41 PM, Charlie Quebec wrote:
> I was taught to always judge my circuit by the angles, and to do so with no instruments, so I’ve never been in a bad position on final.
> What on earth do you do in the US that leads to the need for s turns, 360s etc?
> In my winch training, I did several highly modified full circuits from 400ft with ease.

--
Dan, 5J

[[email protected]]

On Sunday, April 28, 2019 at 1:41:47 AM UTC-4, Charlie Quebec wrote:
> I was taught to always judge my circuit by the angles, and to do so with no instruments, so I’ve never been in a bad position on final.
> What on earth do you do in the US that leads to the need for s turns, 360s etc?
> In my winch training, I did several highly modified full circuits from 400ft with ease.

Most of my non-standard patterns here in the U.S. have come at the end of contest finishes. Whether using a finish line with a high-speed pass or a cylinder with a high floor, I was frequently lower or higher (respectively) and in closer proximity with other gliders than if I were just floating in to land after a pleasant local flight. At one mountain site, I finished very high for safety and made a high, somewhat longer pattern. Another pilot who had finished lower and was behind me called nervously to ask if I would hurry it up. I told him to turn in and I would extend. I turned onto base a little farther out than usual and then did a couple of S-turns until I could see him touch down and roll out safely, then turned final and landed using my normal high approach with brakes and slip.

Given a choice, I'm usually high. I feel like I can get rid of almost any amount of altitude safely (brakes, slip, dive, S-turns, whatever). But I can't get it back.

Chip Bearden
JB

[CindyB[_2_]]

On Wednesday, April 17, 2019 at 8:28:44 AM UTC-7, wrote:
> I always assumed that there are more overshoot airport accidents than undershoot ones. That is mainly due to our general knowledge that it's better to be too high than not high enough.
> Am I correct here ?
> Dan

You are not correct. We make impacting short a habit -- too clean, too low, too late on baseleg turn, too often undercalling the wind, Not Understanding How to Descend. Thus the typical belief is that an approach should be shallow.
"I'm in a 45:1 glider, I have to make a longer approach....."
This is Wrong.
If you ever find yourself having to clean up on Final,
you are doing it Wrong. You should be progressively dirtying-out.


soaringsafety.org
click on Flight Safety Programs, Accident Prevention, SSF Annual Reports

Pick a Year and begin reading. It is hugely enlightening.

In 2017 - (most recently available results):
Hit Object on Final - 2 (too low)
Stall/Spin - 1
Hit Object on Ground - 1
Land Short - 1
Land Long - 0
Other - 1

2016
Hit Object on Final - 3 (too low)
Stall/Spin - 1 into trees on approach(too low)
Hit Object on Ground - 2
Land Short - 0
Land Long - 1 asw28 over trees+long into trees
Other - 1 (lost-hit trees during outlanding=short)

2015
Hit Object on Final - 2 (too low)
Land Short - 2
Land Long - 1 (failed to open spoilers, three passes)

The majority of the US accidents are screwups on takeoff. PT3s
are the typical result of the screwup. This is why I offered my
SSA Webinar on Takeoff Dangers and How to Avoid Them. I would like to reduce this category of wreckage.
Go see it free anytime on the SSA website.

The second most common accident is landing short/hitting obstacles
short of the HOME runway. Trees, wires, fences, crops. Then the same
problem at outlandings .... being short of the targeted landing space.

I fully believe this comes from a failure to teach effective descent skills.. The The S's allow us to descend massively.
Spoilers, Slips, Speed.

Use the ones you are comfortable employing. Get training to expand your
personal envelope to include more tools. A normal approach should be half-dirty.

Drag increases exponentially with an increase in airspeed.
The truth is -- that exponent doesn't disappear after it has exhausted the
potential energy (altitude). When you round out fully dirty (all flaps or all spoilers or both/all) at speed -- the next thing to be scrubbed away exponentially is the kinetic energy. The speed WILL dissipate very quickly,
and even students realize that this has suddenly become a very normal looking landing.

Pilots who are 'handicapped' with flaps-only ships understand this.

Manufacturers shifted away from true landing/drag flaps, and the creation of landing-short accidents by pilots, to a more forgiving tool - spoilers. A reduction in landing flaps only creates a loss of lift and falling further below glide slope. Spoilers allow the reduction or return of lifting qualities to the airfoil for those oft-found occasions of being too-low on final approach.

I wish I could find my video on an old hard drive of a diving approach full dirty in a DuoDiscus (plain-Jane early one) that I had used in a landing training talk for an SSA Convention in about 2004. FULL Dirty with speed works. And Pete B knows it (as do my students).

Thanks,
Cindy B