When gliders fail in flight, but pilots manage to land

[son_of_flubber]

Bruno Vassel recalls how the control stick broke off in a glider pilot's hand and how that pilot landed the aircraft safely (using rudder to turn and trim to control speed).
https://www.youtube.com/watch?v=kF0tTzvU8IM&t=411s

Another favorite scenario is 'one spoiler stuck open'... the pilot opened the other spoiler to match and landed promptly.

Spoilers frozen shut... slip to land.

What else breaks and what if anything could be done about it?

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

The list is long and varied........

Way back when, I used to try patterns (at altitude) with no elevator, just use flaps and slips (ASW-20A, manual elevator connect) "just in case" we forgot to connect the elevator.
I have done other, "WTF attempts" in various gliders, all at altitude.

Better to try all sorts of "stupid stuff" at altitude with a high chance of recovery rather than in the pattern.

How about this.....thinking you dumped all water from a ASW-20C, going into a farmers field, things seem wrong, revert to....."does it look right, does it sound right, does it feel right....if no....FRIKKIN fix it!".
I did that in PA once.
Thought water was dumped (we had worked on dump valve the night before), so, fell off the ridge and landed shortly thereafter.
If I went by the book, never would have made the field.
It didn't feel right, so I sped up.
Found a full load of water when I went to derig later.

Yes, good to do "what if's" at altitude (thinking benign spiral when IFR), but you're limited on possible "crap happens" ideas.

[Roy B.]

Incident report of a '29 that lost all rudder control and managed to climb 2300', glide 65 km, and return to airport of origin for safe landing.

https://docs.google.com/document/d/10AQAGwc4mAVFqB5UJ6jjbY47acnbXfOiJ38hqfT2VRU/edit

ROY

[Dan Marotta]

Had one dump valve open but not the other (both wings and tail tank
controlled by the same lever).Â* Landed my LAK-17a with one dry wing and
the other had 25 gallons.Â* I did not realize I had a problem until just
before coming to a stop when one wing slammed down uncontrollably.Â*
Speed was down to a slow walk at that time.Â* Great ship, that LAK-17a!

On 6/23/2018 4:21 PM, Charlie M. (UH & 002 owner/pilot) wrote:
> The list is long and varied........
>
> Way back when, I used to try patterns (at altitude) with no elevator, just use flaps and slips (ASW-20A, manual elevator connect) "just in case" we forgot to connect the elevator.
> I have done other, "WTF attempts" in various gliders, all at altitude.
>
> Better to try all sorts of "stupid stuff" at altitude with a high chance of recovery rather than in the pattern.
>
> How about this.....thinking you dumped all water from a ASW-20C, going into a farmers field, things seem wrong, revert to....."does it look right, does it sound right, does it feel right....if no....FRIKKIN fix it!".
> I did that in PA once.
> Thought water was dumped (we had worked on dump valve the night before), so, fell off the ridge and landed shortly thereafter.
> If I went by the book, never would have made the field.
> It didn't feel right, so I sped up.
> Found a full load of water when I went to derig later.
>
> Yes, good to do "what if's" at altitude (thinking benign spiral when IFR), but you're limited on possible "crap happens" ideas.

--
Dan, 5J

[Jonathan St. Cloud]

On Saturday, June 23, 2018 at 2:56:07 PM UTC-7, son_of_flubber wrote:
> Bruno Vassel recalls how the control stick broke off in a glider pilot's hand and how that pilot landed the aircraft safely (using rudder to turn and trim to control speed).
> https://www.youtube.com/watch?v=kF0tTzvU8IM&t=411s
>
> Another favorite scenario is 'one spoiler stuck open'... the pilot opened the other spoiler to match and landed promptly.
>
> Spoilers frozen shut... slip to land.
>
> What else breaks and what if anything could be done about it?

Didn't ASCSC's SZD-50-3 PUCHACZ, lose a rudder at Warner, land and get back in take-off line up before someone noticed a missing rudder?

[RR]

Someone told me once, that if I sailed a triangle with my boat without touching the tiller I would learn a ton about my boat. Very true. So only trimming sails, I sailed with only the sheets. Tacking without the tiller was very interesting. The boat was a 30ft etchells, monohull. I did, indeed, learn a ton.

So I thought I would try it in my glider. I flew a 50k triangle without touching the stick. Half with rudder and flaps, half with rudder alien. Learned a ton.

With flap, it was almost too easy. The flap is like having a low travel elevator.

Trimmed up slightly to allow a 360 turn I could manage wide thermal turns. Going straight with rudder alone I would need to kick rudder near the top of the phugoid oscillation in pitch, to damp it out. So it was a bit more zig zag than straight line.

But fun figuring it all out, and you will learn a lot about your aircraft.
They are all different in there dynamic stability. Mine at the time was a 304cz...

[Karl Striedieck[_2_]]

If a pilot gets in the air without elevator control all is not lost. For a flapped ship like an ASW-20 there are still three controls that affect pitch/speed: spoilers, flaps and ailerons (roll). The latter will control pitch very easily via varying bank angle. If the nose is going to rise above the desired pitch angle (a little below the horizon) put in some bank until the pitch up stops then roll out the amount needed to maintain a stable glide angle.

For a non-flapped ship, aileron and spoilers are available.

An extreme aft cg makes these alternate control options trickier.

KS

In the case of one spoiler opening in flight (happened to me-ASW-17) slowing to stall speed may allow it to fall closed and stay there if speed is kept low. When the airport is well in reach unload the stick a little to open the lose spoiler and open the connected one for a full spoiler landing.







On Saturday, June 23, 2018 at 5:56:07 PM UTC-4, son_of_flubber wrote:
> Bruno Vassel recalls how the control stick broke off in a glider pilot's hand and how that pilot landed the aircraft safely (using rudder to turn and trim to control speed).
> https://www.youtube.com/watch?v=kF0tTzvU8IM&t=411s
>
> Another favorite scenario is 'one spoiler stuck open'... the pilot opened the other spoiler to match and landed promptly.
>
> Spoilers frozen shut... slip to land.
>
> What else breaks and what if anything could be done about it?

[[email protected]]

Thx, KS. From memory, years ago you wrote a piece in Soaring about flying with inoperable controls. If so, could you point us to it? I tried to find it last night using the SSA archives but could not.

JB

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

Good thoughts, thanks.

From what I remember, the most common "loss of a control surface" in flight are usually with glass ships.

-elevator not connected (more common on earlier ships before auto control connect)
-dirty connectors/dry lube in pushrod ball latches or on the ball itself
-failed gap seal safety tape (most common on the top of the elevator, sorta outta sight outta mind) that flips up when flying blanking the control
-a case where a ship was refurbished (2-33?) and cables were run backwards/crossed! Positive control check should make sure it's connected as well as going the anticipated way.

Positive control check helps a lot.
Crude "test" is to move controls quickly while watching them. If it is not connected, inertia may yield a clunk as the pushrod hits the ball. May.
Check safety tapes, replace as needed.
At least in the spring, clean control connect balls with a rag and WD-40 (decent safe solvent), lube the ball and locking mechanism.
After connecting a rod, try to lift it off near the ball. A slow/dirty lock may allow the rod to come off. Just had this a few weeks ago rigging a -21..

Everything you do on the ground, is one more way to avoid an issue in the air.

PS, the closest I have been (that I am aware of) to a control issue was a late day speed pass at home airport. In the pull-up, hit a gust that unlocked the dive brakes (-24) at a bit over 100MPH. Good for me, they didn't bend open, got them closed, cut pattern short, landed fine. Yes, we checked everything out throughly when derigging.

[John Leibacher]

On Sunday, June 24, 2018 at 7:50:34 AM UTC-7, wrote:
> Thx, KS. From memory, years ago you wrote a piece in Soaring about flying with inoperable controls. If so, could you point us to it? I tried to find it last night using the SSA archives but could not.
>
> JB

Maybe

Karl H. Striedieck: Has Thought on (Elevator Hookup) Problem, Nov, 1993, page 3 (Letter) [Preflight]

or
Karl H. Striedieck: Attitude Problems (from No Elevator Control), Jul, 1994, pages 43-44 [Safety; Patterns and Landings; Instruction; Equipment\Hotellier Fittings]

Try entering KS's name in the search box at the bottom of

http://soaringweb.org/Soaring_Index/

2E

[Karl Striedieck[_2_]]

Thanks (again) Herr Leibacher!! It was indeed July 1994.

KS










On Saturday, June 23, 2018 at 5:56:07 PM UTC-4, son_of_flubber wrote:
> Bruno Vassel recalls how the control stick broke off in a glider pilot's hand and how that pilot landed the aircraft safely (using rudder to turn and trim to control speed).
> https://www.youtube.com/watch?v=kF0tTzvU8IM&t=411s
>
> Another favorite scenario is 'one spoiler stuck open'... the pilot opened the other spoiler to match and landed promptly.
>
> Spoilers frozen shut... slip to land.
>
> What else breaks and what if anything could be done about it?

[Andreas Maurer]

On Sat, 23 Jun 2018 14:56:05 -0700 (PDT), son_of_flubber
> wrote:

>Bruno Vassel recalls how the control stick broke off in a glider pilot's hand and how that pilot landed the aircraft safely (using rudder to turn and trim to control speed).
>https://www.youtube.com/watch?v=kF0tTzvU8IM&t=411s
>
>Another favorite scenario is 'one spoiler stuck open'... the pilot opened the other spoiler to match and landed promptly.
>
>Spoilers frozen shut... slip to land.
>
>What else breaks and what if anything could be done about it?


1. L'Hotellier links.

Had one serious incident yesterday:
ASW-20, l'Hotellier of the (inner) wing flap unlocked, causing the
wing flap to go slightly negative after two minutes of aerotow.
According to the pilot he had done a full control check after
assembling the 20.
He needed nearly full aileron to keep the glider level and land it
successfully.


The (inexperienced) pilot made the follwing mistakes:

- Didn't lock the l'Hotellier connection properly (obviously)

- Made the approach and landing with flaps 4 (positive). With the
negative inner flap one one wing this resultetd in a serious
asymmetric lift configuration.

- Pilot approached faster than usual (115 kp/h, 60 kts) with flaps 4.
Aerodynamical forces at this speed pushed the unconnected flap even
further into "negative", increasing the asymmetric lift.


The pilot obvously didn't know how his wing flaps worked - setting
them to 2 or 1 (negative) would have solved the asymmetry and only
needed an additional 7 kts higher approach speed.


2. ASW-24
Elevator trim bowden broke while thermalling and trim was set
significantly tail-heavy. Experienced pilot landed safely, but had to
push the stick forward all the time.


Cheers
Andreas

[jfitch]

On Sunday, June 24, 2018 at 2:19:22 PM UTC-7, Andreas Maurer wrote:
> On Sat, 23 Jun 2018 14:56:05 -0700 (PDT), son_of_flubber
> > wrote:
>
> >Bruno Vassel recalls how the control stick broke off in a glider pilot's hand and how that pilot landed the aircraft safely (using rudder to turn and trim to control speed).
> >https://www.youtube.com/watch?v=kF0tTzvU8IM&t=411s
> >
> >Another favorite scenario is 'one spoiler stuck open'... the pilot opened the other spoiler to match and landed promptly.
> >
> >Spoilers frozen shut... slip to land.
> >
> >What else breaks and what if anything could be done about it?
>
>
> 1. L'Hotellier links.
>
> Had one serious incident yesterday:
> ASW-20, l'Hotellier of the (inner) wing flap unlocked, causing the
> wing flap to go slightly negative after two minutes of aerotow.
> According to the pilot he had done a full control check after
> assembling the 20.
> He needed nearly full aileron to keep the glider level and land it
> successfully.
>
>
> The (inexperienced) pilot made the follwing mistakes:
>
> - Didn't lock the l'Hotellier connection properly (obviously)
>
> - Made the approach and landing with flaps 4 (positive). With the
> negative inner flap one one wing this resultetd in a serious
> asymmetric lift configuration.
>
> - Pilot approached faster than usual (115 kp/h, 60 kts) with flaps 4.
> Aerodynamical forces at this speed pushed the unconnected flap even
> further into "negative", increasing the asymmetric lift.
>
>
> The pilot obvously didn't know how his wing flaps worked - setting
> them to 2 or 1 (negative) would have solved the asymmetry and only
> needed an additional 7 kts higher approach speed.
>
>
> 2. ASW-24
> Elevator trim bowden broke while thermalling and trim was set
> significantly tail-heavy. Experienced pilot landed safely, but had to
> push the stick forward all the time.
>
>
> Cheers
> Andreas

Another check on controls (lacking help) is to back drive them: Move the aileron on one side and watch the stick and aileron on the other side. Move the elevator and observe the stick move. On some gliders you can pull open the spoiler paddle (once unlocked) and see the other one come up. This demonstrates continuity through the fuselage, and is an indicator that things are connected.

[[email protected]]

Not sure everyone understands how the rudder control system in most of our ships, works. Typically, a cable on each side from the rudder to the pedal with a spring at each pedal (to keep the pedal erect). If a cable breaks or becomes disconnected, the pedal on that side will be pulled forward by its spring........ends up flat on the floor! Meanwhile, the spring on the other rudder pedal will pull in uncommander rudder! Sensing this, the pilot tries to correct with opposite rudder, but that puppy is flat on the floor! Next, the pilot applies opposite aileron before the uncommanded rudder gets out of hand. This works, but the ship is now flying in a full slip!
This is exactly what happened to two pilots flying an ASH-25, a few years back and they were on the ridge! The PIC flew away from the rocks, in a full left slip and made a radio call giving his location, situation and intentions (bail out). Hearing his call, I thought for a few seconds, then asked if the rudder pedals in the other seat were working? Anxious seconds later, a much relieved voice reported that, in fact the front seat rudder pedals were working normally. They headed for the nearest airport with the front seat pilot holding enough right rudder pedal to keep the rudder near neutral.
Something to add to your bag of tricks,
JJ

[[email protected]]

> Karl H. Striedieck: Attitude Problems (from No Elevator Control), Jul, 1994, pages 43-44 [Safety; Patterns and Landings; Instruction; Equipment\Hotellier Fittings]
>
Yes, John, that's the one! I don't know why I didn't see it in the search results last night. Excellent, must-read article by KS about what to do if....

Chip Bearden

[JS[_5_]]

The ASH25 incident JJ recounts brings this to mind:
In 2-seater situations where the second pilot is essentially a "ride", is there consideration of the second (if qualified) pilot taking control?
Jim

[Eric Munk]

Broken rudder cable in a Puchacz. Used ailerons to sideslip it all
the way to landing and full airbrakes that reduced rudder
effectiveness by about half. Interesting approach and landing
across the field.

Loose gapseal in LS4 in spiraldive on aileron. Unable to roll out
until combination of opposite aileron, rudder and full airbrakes
slowly overcame it.

[Eric Munk]

Broken rudder cable in a Puchacz. Used ailerons to sideslip it all
the way to landing and full airbrakes that reduced rudder
effectiveness by about half. Interesting approach and landing
across the field.

Loose gapseal in LS4 in spiraldive on aileron. Unable to roll out
until combination of opposite aileron, rudder and full airbrakes
slowly overcame it.

[[email protected]]

I believe there is a similar article by Richard Johnson. Remember stick problem - either no forward travel or stick limited to keeping glider in high angle of attack - put glider in turn where that stick configuration is required, buy some time to make a more thought out decision.

Mark

[BobW]

On 6/23/2018 3:56 PM, son_of_flubber wrote:
> Bruno Vassel recalls how the control stick broke off in a glider pilot's
> hand and how that pilot landed the aircraft safely (using rudder to turn
> and trim to control speed).
> https://www.youtube.com/watch?v=kF0tTzvU8IM&t=411s
>
> Another favorite scenario is 'one spoiler stuck open'... the pilot opened
> the other spoiler to match and landed promptly.
>
> Spoilers frozen shut... slip to land.
>
> What else breaks and what if anything could be done about it?

Progressive failure of a weldment inter-connecting rudder cables to pushrod
actuating rudder (Zuni S/N 3). Initial symptom was isolated (intermittent,
uncommanded) yaw-"pulses" at thermalling/low speed (weak, barely sustainable,
day). After 2nd occurrence, eventually concluded "something" wasn't right in
rudder control system; determined to precautionarily land from a pattern
sufficiently large to not require rudder. Symptom increased to intermittent
(downwind/final), low-frequency (several cycles/sec?), large amplitude (nose
motion vs. "buzz") rudder flutter. Otherwise uneventful pattern/landing.

Unable to diagnose problem at field; ultimately diagnosed at home. Removal of
weldment and subsequent eyeball/microscopic inspection led me (and George
Applebay - ship designer/builder) to conclude an imperfect weld connecting
"fishmouthed" pushrod connection arm to weldment's vertical tube left behind a
small hole/stress riser. Fracture path showed surface rust at/within hole and
bright metal along subsequent fracture path. Pushrod-connecting arm remained
(barely) attached to central mounting shaft, with pre-disassembly/post-landing
position of all rudder actuation controls essentially as-designed.

New part made/installed.

Bob W.

---
This email has been checked for viruses by AVG.
https://www.avg.com

[[email protected]]

If a rudder cable should break in flight, what can you try, before hitting the silk? First off, fly the sailplane. You should be able to keep the wings level by fighting the uncommanded rudder input with opposite aileron. Let's assume the right rudder cable broke and the left pedal spring has pulled in full left rudder. If you can get hold of the rudder cable, you may be able to pull on the broken cable and cause the rudder to come back to center.. Pull forward on the right rudder cable or aft on the left rudder cable. I don't believe this is a viable solution in most ships because the rudder cables are inside a nylon sleeve and not accessible in flight. What else could you try (while holding right aileron to keep the wings level)? The problem is the left rudder pedal spring is pulling in unwanted rudder, so how can we get it to stop doing that? Try and get your left foot over the left rudder pedal and pull aft on the top of the pedal with the heal of your left foot............not likely, I hear you saying, but what if you pull the rudder pedal adjustment all the way back? That might get the pedal close enough to get the heal of your left foot over the pedal? If successful, pull it all the way back, this will relieve the spring tension that is applying the unwanted rudder input. Home free, right? Well, maybe just pretend your Joe Cessna driver who doesn't use the rudder much, anyway!
What do you think?
JJ

One more little 'tid-bit while we're talking about the rudder cables..........if you don't like the angle of your pedals (most stand too straight up for my liking) you can lean them both forward by simply adjusting the length of both cables. Install a 1" steel carabiner where the cables end forward of the rudder pedals. Sound crazy, but it's true!
Be sure to check that your new pedal position, still giver full rudder throw!

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

Not picking......just commenting.

While I hate to think of a control failure in flight, a thread like this may prompt others to try "stupid stuff" at altitude.
I don't know who said it first (maybe one of the Wrights?), don't stop flying until all motion has ended!
Basically, even if a wrong input, keep trying something until things stop. Keep trying "pilot ****" until things stop moving.
A semi controlled crash is way better than an uncontrolled crash.

Only comment is a pilot (decades ago in NJ) that landed a SEL powered plane (on a golf fairway) and drove it between 2 trees. His comment, "I heard shedding the wings was a good thing in a crash".
They could have refueled, taken off, gone to the local airport.
Whatever.

Yes, this is a good thread, may make peeps think a bit.
May.

[son_of_flubber]

My only in-flight glider failure happened back when I was a 'baby level pilot'. Fortunately, it was a baby level glider failure, but at the time, I thought I needed a yaw string to fly coordinated with confidence. During aerotow, my yaw string departed the canopy. 'Oh s***!'

I heard my instructor's voice echo, 'stay on tow, altitude is your friend, give yourself some time to work things out, stay calm.' I softly vocalized 'stay calm'.

I knew about 'spin on turn to base', but I had also practiced 'slip on turn to base'. Slip good, skid bad.

I added 5 knots to my pattern speed, and kept the rudder neutral.

[[email protected]]

Many years ago, a friend of mine had the linkage to both ailerons in his 1-26 come disconnected in flight. The pins in the linkage fell out inside the fuselage, and we never did find the safety pin to see what happened to it.

Anyway, the 1-26 has quite a bit of wing dihedral, and he managed to bring it back to the field and land it, using rudder for slow gradual turns. The glider is still flying today.

Jim Beckman in NJ

[Soartech]

Two years ago, on my first flight of the year I saw that the airspeed indicator was not working (read zero). Feeling comfortable with approximate airspeeds I did a refresh on where close to stall was and went off on a 2 1/2 hour cross country flight with no problems. Kept the speed up and nose down a bit on pattern and landing. Looking into the nose area I found that the plastic tubing had slipped off the Pitot tube in the nose, probably from a long trailer ride. It is now secured with a Ty-wrap.

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

Decades ago, I did a "first flight of the season" in a ASW-20. Normal preflight of, "cup hand around tail probe and blow" yielded sorta normal needle movement.
At about 200', airspeed was low (glider felt solid), so continued flight.
Flew for a couple hours, landed fine, derigged.
Found a rodent had chewed through a pressure tube. A quick blow looked fine, steady state had a leak.
I had reverted to, "does it look good, does it feel good, does it sound good?".
Decent short cross country, woulda sucked for a competition.

So, unless IFR, revert to basics, hopefully you were taught the basics...... IFR stresses, "believe the instruments, verify what is correct".