Sacrificial layer for gear-up protection.

[Bill D]

Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday. (Of course, you private owners never land gear-up...) Is there a way to minimize the damage when the inevitable day arrives?

Maybe. One of my favorite materials is UHMW-PE - a plastic with many superlative characteristics including astonishing abrasion resistance and a very low coefficient of friction. A 9mm thick strip, 150mm wide might very well withstand a gear-up landing of an 850 kg glider. It's also very light, cheap and a shade of white closely matching gel-coat.

Until recently, there was no way to glue this stuff to anything even itself but new epoxy adhesives have appeared on the market that advertize the ability to stick it to almost anything including fiber reinforced composite epoxy structures like glider belly's and wing tips.

So, obviouisly, some testing is in order before slapping a strip of UHMW-PE on the belly of your glider. A test rig on a pick-up's reciever hitch could slam a patch of it down on a concrete runway to simulate a gear-up. Anybody interested?

[[email protected]]

Bill,

Could you provide the brand name of the particular epoxy that will stick to this stuff? I would like to install a couple strips to the down-turned wing tip skids on my LS-3. The design of the tips makes it difficult to use mechanical fasteners.

Thanks,

Ron C.

[son_of_flubber]

On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday.

I've seen this eventuality addressed on an L-23 by putting a ziptie around the gear lowering handle.

[Bill D]

On Friday, May 15, 2015 at 1:31:32 PM UTC-6, wrote:
> Bill,
>
> Could you provide the brand name of the particular epoxy that will stick to this stuff? I would like to install a couple strips to the down-turned wing tip skids on my LS-3. The design of the tips makes it difficult to use mechanical fasteners.
>
> Thanks,
>
> Ron C.

Here's one - there are dozen more.
http://reltekllc.com/adhesivesforuhmw.aspx

Just Google "uhmw-pe epoxy adnesive"

[Bob Pasker]

On Friday, May 15, 2015 at 3:36:48 PM UTC-4, son_of_flubber wrote:
> On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> > Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday.
>
> I've seen this eventuality addressed on an L-23 by putting a ziptie around the gear lowering handle.

all of the club retracts I've flown have had the handle disabled, either with a ziptie or with safety wire

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

On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday. (Of course, you private owners never land gear-up...) Is there a way to minimize the damage when the inevitable day arrives?
>
> Maybe. One of my favorite materials is UHMW-PE - a plastic with many superlative characteristics including astonishing abrasion resistance and a very low coefficient of friction. A 9mm thick strip, 150mm wide might very well withstand a gear-up landing of an 850 kg glider. It's also very light, cheap and a shade of white closely matching gel-coat.
>
> Until recently, there was no way to glue this stuff to anything even itself but new epoxy adhesives have appeared on the market that advertize the ability to stick it to almost anything including fiber reinforced composite epoxy structures like glider belly's and wing tips.
>
> So, obviouisly, some testing is in order before slapping a strip of UHMW-PE on the belly of your glider. A test rig on a pick-up's reciever hitch could slam a patch of it down on a concrete runway to simulate a gear-up. Anybody interested?

While a "sacrificial layer" seems good, best method I've seen is to have the offender help with doing the repairs.
Granted, it means some glider downtime, but "word of mouth" goes miles as a reminder.
Since I tend to do "final finish & polish", I have a vested interest in what happens to ships.
;-)

[yes, UHMW-PE is a great material, even "good" adhesives are short term in my eyes.]

[Bill D]

On Friday, May 15, 2015 at 3:29:47 PM UTC-6, Bob Pasker wrote:
> On Friday, May 15, 2015 at 3:36:48 PM UTC-4, son_of_flubber wrote:
> > On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> > > Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday.
> >
> > I've seen this eventuality addressed on an L-23 by putting a ziptie around the gear lowering handle.
>
> all of the club retracts I've flown have had the handle disabled, either with a ziptie or with safety wire

I don't think that's going to work with a Discus

[Mike the Strike]

On Friday, May 15, 2015 at 2:29:47 PM UTC-7, Bob Pasker wrote:
> On Friday, May 15, 2015 at 3:36:48 PM UTC-4, son_of_flubber wrote:
> > On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> > > Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday.
> >
> > I've seen this eventuality addressed on an L-23 by putting a ziptie around the gear lowering handle.
>
> all of the club retracts I've flown have had the handle disabled, either with a ziptie or with safety wire

Disabling an aircraft control sounds not only insane but likely also illegal.

Mike

[Bill D]

On Friday, May 15, 2015 at 3:54:17 PM UTC-6, Charlie M. (UH & 002 owner/pilot) wrote:
> On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> > Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday. (Of course, you private owners never land gear-up...) Is there a way to minimize the damage when the inevitable day arrives?
> >
> > Maybe. One of my favorite materials is UHMW-PE - a plastic with many superlative characteristics including astonishing abrasion resistance and a very low coefficient of friction. A 9mm thick strip, 150mm wide might very well withstand a gear-up landing of an 850 kg glider. It's also very light, cheap and a shade of white closely matching gel-coat.
> >
> > Until recently, there was no way to glue this stuff to anything even itself but new epoxy adhesives have appeared on the market that advertize the ability to stick it to almost anything including fiber reinforced composite epoxy structures like glider belly's and wing tips.
> >
> > So, obviouisly, some testing is in order before slapping a strip of UHMW-PE on the belly of your glider. A test rig on a pick-up's reciever hitch could slam a patch of it down on a concrete runway to simulate a gear-up. Anybody interested?
>
> While a "sacrificial layer" seems good, best method I've seen is to have the offender help with doing the repairs.
> Granted, it means some glider downtime, but "word of mouth" goes miles as a reminder.
> Since I tend to do "final finish & polish", I have a vested interest in what happens to ships.
> ;-)
>
> [yes, UHMW-PE is a great material, even "good" adhesives are short term in my eyes.]

Much better to just put the glider back on its wheel and go fly. Usually the offender is sufficiently embarassed.

Are you saying the UHMW-PE adhesives don't really last?

[Bill T]

Not the best idea for a Club LS4 going cross country.
BillT

[bumper[_4_]]

On Friday, May 15, 2015 at 11:59:26 AM UTC-7, Bill D wrote:

> So, obviouisly, some testing is in order before slapping a strip of UHMW-PE on the belly of your glider. A test rig on a pick-up's reciever hitch could slam a patch of it down on a concrete runway to simulate a gear-up. Anybody interested?

I've been using 3/4 thick UHMW PE on my tractor mounted snow blower for the last couple of years on concrete, asphalt and pavers. Very little decrease in thickness. Loading is at least 15 psi. And, they don't mark up the surface. Material can be heat formed. I'm using countersunk bolts to mount the material.

[[email protected]]

Hmm, did anybody thought about accoustic gear warnings when deploying airbrakes in club gliders??
Or even more sophisticated "get the f... gear out before landing" voice warning???

just my 2ct.

;O)

[Martin Gregorie[_5_]]

On Sat, 16 May 2015 01:44:06 -0700, dr.patrese wrote:

> Hmm, did anybody thought about accoustic gear warnings when deploying
> airbrakes in club gliders??
> Or even more sophisticated "get the f... gear out before landing" voice
> warning???
>
We used to have them fitted. Now removed because we'd rather have the
glider landed safely with the wheel up than crashed because the pilot got
distracted by the warning.

However, our field is grass-covered all year round. I suppose its
possible we'd think the otherwise if our runways were sealed, gravelled
or baked dirt.


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

[Bill D]

On Saturday, May 16, 2015 at 2:44:08 AM UTC-6, wrote:
> Hmm, did anybody thought about accoustic gear warnings when deploying airbrakes in club gliders??
> Or even more sophisticated "get the f... gear out before landing" voice warning???
>
> just my 2ct.
>
> ;O)

I'd guess the overwhelming majority of gear-up incidents were gliders with gear warnings installed. It helps but it's not foolproof.

[Dan Marotta]

That just reflects a poor training program!

In every club I've been a member of, there's always been an operations
manager on duty at the takeoff/landing line. It should be his job to
verify gear down on every club ship in the pattern. Good training,
observant people, and functional radios should prevent gear up landings.

I would leave any club that wired my gear handle down.

On 5/15/2015 3:29 PM, Bob Pasker wrote:
> On Friday, May 15, 2015 at 3:36:48 PM UTC-4, son_of_flubber wrote:
>> On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
>>> Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday.
>> I've seen this eventuality addressed on an L-23 by putting a ziptie around the gear lowering handle.
> all of the club retracts I've flown have had the handle disabled, either with a ziptie or with safety wire

--
Dan Marotta

[[email protected]]

So you think having 3 green lamps in every real airplane is not a good idea to prevent landing on it's belly?

And when you deploy spoilers on the beginning of final lets say 300 AGL there is lots of time to put the gear down without geting panict by a "beep".
But I would also prefer the voice module...

[Sarah[_2_]]

A club used to fixed gear with a retract addition should definitely enforce a written landing checklist- backed up with an audible gear warning.

A switch on the spoiler/flaps ought to work. Instead of yet another buzzer ( easily confused with loggers & pda warnings ) I would put together something with a calm voice saying... "landing gear landing gear landing gear ..." until the pilot gets the message.

These ought to do the trick. Just add speaker, 12v-5v supply and microswitches.

https://www.adafruit.com/products/2133
https://www.adafruit.com/products/2130


On Saturday, May 16, 2015 at 3:44:08 AM UTC-5, wrote:
> Hmm, did anybody thought about accoustic gear warnings when deploying airbrakes in club gliders??
> Or even more sophisticated "get the f... gear out before landing" voice warning???
>
> just my 2ct.
>
> ;O)

[Martin Gregorie[_5_]]

On Sat, 16 May 2015 09:42:45 -0700, dr.patrese wrote:

> So you think having 3 green lamps in every real airplane is not a good
> idea to prevent landing on it's belly?
>
> And when you deploy spoilers on the beginning of final lets say 300 AGL
> there is lots of time to put the gear down without geting panict by a
> "beep".
> But I would also prefer the voice module...

If I was going to install a wheel warning I'd prefer a silent indicator
near the top of the panel to a noise of any sort, for instance a single
bi-colour LED that is off with wheel up and brakes closed, dim green when
the wheel is locked down and brighter red if the brakes are open with the
wheel up or not locked down.

Don't forget that there are circumstances when you'd want to open the
brakes when not intending to land: obvious examples are when shedding
height at the end of a flight preparatory to joining the circuit, to
avoid being sucked up into cloud or when coming down at the end of a high
wave flight. In these cases a loud buzzer or a vocal warning would be an
unwanted distraction.


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

[Bill D]

On Saturday, May 16, 2015 at 11:00:05 AM UTC-6, Sarah wrote:
> A club used to fixed gear with a retract addition should definitely enforce a written landing checklist- backed up with an audible gear warning.
>
> A switch on the spoiler/flaps ought to work. Instead of yet another buzzer ( easily confused with loggers & pda warnings ) I would put together something with a calm voice saying... "landing gear landing gear landing gear ..." until the pilot gets the message.
>
> These ought to do the trick. Just add speaker, 12v-5v supply and microswitches.
>
> https://www.adafruit.com/products/2133
> https://www.adafruit.com/products/2130
>
>
> On Saturday, May 16, 2015 at 3:44:08 AM UTC-5, wrote:
> > Hmm, did anybody thought about accoustic gear warnings when deploying airbrakes in club gliders??
> > Or even more sophisticated "get the f... gear out before landing" voice warning???
> >
> > just my 2ct.
> >
> > ;O)

Recently a Beech Baron slid in on its belly. No malfunction, just pilot error - this despite a suite of lights and audible warning systems.

Q. Didn't you hear the gear warning?
P. I couldn't hear it over the yelling from the passengers

Q. What were they yelling?
P. Put the @$%@!% gear down!

p.s. The Baron has fuel drains that extend below all other airframe structure when the gear is up so they touch the runway first in a gear-up landing.. This usually results in a fireball but luckily in this case the airplane just left a long streak ending in a puddle of evaporating 100LL.

[Don Johnstone[_4_]]

At 16:06 16 May 2015, Dan Marotta wrote:
>That just reflects a poor training program!
>
>In every club I've been a member of, there's always been an operations
>manager on duty at the takeoff/landing line. It should be his job to
>verify gear down on every club ship in the pattern. Good training,
>observant people, and functional radios should prevent gear up landings.
>
>I would leave any club that wired my gear handle down.
>

1. do you really want to put in place a system where it does not matter if
you land wheels up. That is one consequence of the sacrificial layer
application.
2. In the UK it is "forbidden" to warn a glider that he has not deployed
the U/c when on final approach. It is a fact that more serious accidents
have occurred when pilots concentrate on getting the U/c down and forget
about flying the glider. U/c warnings are frowned upon for the same reason,
especially those that are linked to the airbrakes. The theory is that less
damage is likely to ensue from a wheels up landing on an airfield than from
and untidy arrival by a pilot struggling with the U/c lever.
3. Disabling the U/c lever is not an approach I have even heard of before.
It would be illegal to do that over here.

Good training is the key, but as is oft said, there are two types of
pilots, those that have and those that are going to.

[[email protected]]

I have always wondered, why do people get so worked up about gear up landings in a glider ?

Has anyone ever been killed or seriously injured because of a gear up landing in a glider ?

I have seen several gear up landings and none of them caused any injury and only minor damage.

What's the big deal ?

Todd Smith
3S

[Z Goudie[_2_]]

At 21:49 16 May 2015, Don Johnstone wrote:

>Good training is the key, but as is oft said, there are two types o
>pilots, those that have and those that are going to.

..and the lucky ones who go off to the great soaring valhalla before they
do.

Appropo the next post have you ever seen the results of landing wheels up
on a nice rough concrete/aspahalt runway?

[Papa3[_2_]]

On Sunday, May 17, 2015 at 12:15:59 AM UTC-4, wrote:
> I have always wondered, why do people get so worked up about gear up landings in a glider ?
>
> Has anyone ever been killed or seriously injured because of a gear up landing in a glider ?
>
> I have seen several gear up landings and none of them caused any injury and only minor damage.
>
> What's the big deal ?
>
> Todd Smith
> 3S

I've seen someone seriously injured when a pilot was distracted by a radio call on short final (Glider AB, check your gear). The gear was in fact up, but the pilot momentarily lost control of the glider trying to lower it and hit a spectator, seriously injuring that innocent bystander. It would've been far preferable to land gear up. I also know also of a pilot who was distracted on short final by an erroneous call from the ground. In fact, his gear was down and he dealt with it just fine, but it could easily have been a bad outcome.

Anyway, in several thousand glider takeoffs and landings, I've managed to land gear up twice. In both cases, I was extremely current, well-trained, and considered by my peers to be a good pilot. In one of those, I had a working gear warning which I managed to ignore until after the glider settled ("oh, that's what that annoying noise was"). Point being, those who sit on their pedestal and claim that only under-trained or careless pilots land gear up might want to to reconsider their stance. I know of several other very good pilots who have suffered the same fate.

Long-winded intro to the real question which is... yeah, if a strip of bonded sacraficial material works, great. I would point out that one of the real problems is that, with any sort of hard hit, the damage isn't just to the gelcoat. You have to inspect whatever bulkheads and seams are are bonded at the belly. I know of a relatively minor gear up that resulted in a fairly tricky repair on an LS glider.

P3

[Bill D]

On Sunday, May 17, 2015 at 8:35:11 AM UTC-6, Papa3 wrote:
> On Sunday, May 17, 2015 at 12:15:59 AM UTC-4, wrote:
> > I have always wondered, why do people get so worked up about gear up landings in a glider ?
> >
> > Has anyone ever been killed or seriously injured because of a gear up landing in a glider ?
> >
> > I have seen several gear up landings and none of them caused any injury and only minor damage.
> >
> > What's the big deal ?
> >
> > Todd Smith
> > 3S
>
> I've seen someone seriously injured when a pilot was distracted by a radio call on short final (Glider AB, check your gear). The gear was in fact up, but the pilot momentarily lost control of the glider trying to lower it and hit a spectator, seriously injuring that innocent bystander. It would've been far preferable to land gear up. I also know also of a pilot who was distracted on short final by an erroneous call from the ground. In fact, his gear was down and he dealt with it just fine, but it could easily have been a bad outcome.
>
> Anyway, in several thousand glider takeoffs and landings, I've managed to land gear up twice. In both cases, I was extremely current, well-trained, and considered by my peers to be a good pilot. In one of those, I had a working gear warning which I managed to ignore until after the glider settled ("oh, that's what that annoying noise was"). Point being, those who sit on their pedestal and claim that only under-trained or careless pilots land gear up might want to to reconsider their stance. I know of several other very good pilots who have suffered the same fate.
>
> Long-winded intro to the real question which is... yeah, if a strip of bonded sacraficial material works, great. I would point out that one of the real problems is that, with any sort of hard hit, the damage isn't just to the gelcoat. You have to inspect whatever bulkheads and seams are are bonded at the belly. I know of a relatively minor gear up that resulted in a fairly tricky repair on an LS glider.
>
> P3

I've always presumed that real aviators can fly their aircraft and listen to the radio at the same time. If a "check gear" call rattles a pilot so that he loses control of the glider, there's a problem afoot much more serious than radio procedures.

[Charlie Papa[_2_]]

On Sunday, May 17, 2015 at 11:17:29 AM UTC-4, Bill D wrote:
> On Sunday, May 17, 2015 at 8:35:11 AM UTC-6, Papa3 wrote:
> > On Sunday, May 17, 2015 at 12:15:59 AM UTC-4, wrote:
> > > I have always wondered, why do people get so worked up about gear up landings in a glider ?
> > >
> > > Has anyone ever been killed or seriously injured because of a gear up landing in a glider ?
> > >
> > > I have seen several gear up landings and none of them caused any injury and only minor damage.
> > >
> > > What's the big deal ?
> > >
> > > Todd Smith
> > > 3S
> >
> > I've seen someone seriously injured when a pilot was distracted by a radio call on short final (Glider AB, check your gear). The gear was in fact up, but the pilot momentarily lost control of the glider trying to lower it and hit a spectator, seriously injuring that innocent bystander. It would've been far preferable to land gear up. I also know also of a pilot who was distracted on short final by an erroneous call from the ground. In fact, his gear was down and he dealt with it just fine, but it could easily have been a bad outcome.
> >
> > Anyway, in several thousand glider takeoffs and landings, I've managed to land gear up twice. In both cases, I was extremely current, well-trained, and considered by my peers to be a good pilot. In one of those, I had a working gear warning which I managed to ignore until after the glider settled ("oh, that's what that annoying noise was"). Point being, those who sit on their pedestal and claim that only under-trained or careless pilots land gear up might want to to reconsider their stance. I know of several other very good pilots who have suffered the same fate.
> >
> > Long-winded intro to the real question which is... yeah, if a strip of bonded sacraficial material works, great. I would point out that one of the real problems is that, with any sort of hard hit, the damage isn't just to the gelcoat. You have to inspect whatever bulkheads and seams are are bonded at the belly. I know of a relatively minor gear up that resulted in a fairly tricky repair on an LS glider.
> >
> > P3
>
> I've always presumed that real aviators can fly their aircraft and listen to the radio at the same time. If a "check gear" call rattles a pilot so that he loses control of the glider, there's a problem afoot much more serious than radio procedures.

My LX 8080 offers me two gear rpompts: one off tow to 'check gear', and again when agl alt gets low, thus working eve3n in the higher stress of an outlanding.

Very nice to have, and redundant to my buzzer.

[Dan Marotta]

What's the big deal ?

Two words: Cost and down time. (Well... Three words).

On 5/16/2015 10:15 PM, wrote:
> I have always wondered, why do people get so worked up about gear up landings in a glider ?
>
> Has anyone ever been killed or seriously injured because of a gear up landing in a glider ?
>
> I have seen several gear up landings and none of them caused any injury and only minor damage.
>
> What's the big deal ?
>
> Todd Smith
> 3S

--
Dan Marotta

[Mike the Strike]

I too find it hard to believe that a radio call could so rattle a pilot that he loses control. In flying gliders on three continents, I have always maintained radio contact with both the field and traffic as essential to safety.

Most pilots at my local club also call out that their gear is deployed on their downwind leg. I was never trained to do that, so frequently get asked to check my gear. I have screwed up a few landings over the years, but so far have avoided a gear-up.

Mike

[[email protected]]

So it's only a material danger, that's my point.

People get so worked up over it, like it's a safety issue. So much so that they create real safety issues, where people get hurt reacting to radio calls on landing, or last minute lowering the gear.

Todd

On Sunday, May 17, 2015 at 11:38:17 AM UTC-4, Dan Marotta wrote:
> What's the big deal ?
> Two words:* Cost and down time.* (Well...* Three words).
>
>
>
>
> On 5/16/2015 10:15 PM,
> wrote:
>
>
>
> I have always wondered, why do people get so worked up about gear up landings in a glider ?
>
> Has anyone ever been killed or seriously injured because of a gear up landing in a glider ?
>
> I have seen several gear up landings and none of them caused any injury and only minor damage.
>
> What's the big deal ?
>
> Todd Smith
> 3S
>
> --
>
> Dan Marotta

[BobW]

On 5/17/2015 9:17 AM, Bill D wrote:
> On Sunday, May 17, 2015 at 8:35:11 AM UTC-6, Papa3 wrote:
>> On Sunday, May 17, 2015 at 12:15:59 AM UTC-4, wrote:
>>> I have always wondered, why do people get so worked up about gear up
>>> landings in a glider ?
>>>
>>> Has anyone ever been killed or seriously injured because of a gear up
>>> landing in a glider ?
>>>
>>> I have seen several gear up landings and none of them caused any injury
>>> and only minor damage.
>>>
>>> What's the big deal ?
>>>
>>> Todd Smith 3S
>>
>> I've seen someone seriously injured when a pilot was distracted by a
>> radio call on short final (Glider AB, check your gear). The gear was in
>> fact up, but the pilot momentarily lost control of the glider trying to
>> lower it and hit a spectator, seriously injuring that innocent bystander.
>> It would've been far preferable to land gear up. I also know also of a
>> pilot who was distracted on short final by an erroneous call from the
>> ground. In fact, his gear was down and he dealt with it just fine, but
>> it could easily have been a bad outcome.
>>
>> Anyway, in several thousand glider takeoffs and landings, I've managed
>> to land gear up twice. In both cases, I was extremely current,
>> well-trained, and considered by my peers to be a good pilot. In one of
>> those, I had a working gear warning which I managed to ignore until after
>> the glider settled ("oh, that's what that annoying noise was"). Point
>> being, those who sit on their pedestal and claim that only under-trained
>> or careless pilots land gear up might want to to reconsider their stance.
>> I know of several other very good pilots who have suffered the same
>> fate.
>>
>> Long-winded intro to the real question which is... yeah, if a strip of
>> bonded sacraficial material works, great. I would point out that one of
>> the real problems is that, with any sort of hard hit, the damage isn't
>> just to the gelcoat. You have to inspect whatever bulkheads and seams
>> are are bonded at the belly. I know of a relatively minor gear up that
>> resulted in a fairly tricky repair on an LS glider.
>>
>> P3
>
> I've always presumed that real aviators can fly their aircraft and listen
> to the radio at the same time. If a "check gear" call rattles a pilot so
> that he loses control of the glider, there's a problem afoot much more
> serious than radio procedures.
>

Humanity...it's a wonder we've ever survived to create technology and
sailplanes! And considering only the male subset of humankind, it's a wonder
any manage to survive into/measurably-along the journey of adulthood, when you
consider how few of us lack at least one story along the lines of: "Boy, did I
ever get lucky when I did THAT (stupid, ignorant, inattentive,
life-endangering) thing!!!" I don't consider myself particularly
adrenaline-loving, or abbie-normally stupid/ignorant/inattentive, but I've my
own collection of survival stories...fortunately for my embarrassment
quotient, few of them public or related to soaring. If it happens, it must be
possible...

That noted, "What Bill D. said."

Honestly, what percentage of PIC readers haven't yet heard: Aviate! Navigate!
Communicate!

What percentage didn't encounter the aphorism until after their first incident?

What percentage have yet to take it to heart?

My money's on #3 being the largest number.

As for UHMWPE as a belt-n-suspenders adjunct against the day you begin sliding
gear-up on a reasonably smooth surface of any sort, save for the perpetual
minor in-flight aerodynamic drag increase, no obvious downsides spring to my mind.

YMMV,
Bob - no gear-up landings yet; 2 rolling-on-gear-collapses - W.

[GM]

On Friday, May 15, 2015 at 6:23:44 PM UTC-4, Mike the Strike wrote:
> On Friday, May 15, 2015 at 2:29:47 PM UTC-7, Bob Pasker wrote:
> > On Friday, May 15, 2015 at 3:36:48 PM UTC-4, son_of_flubber wrote:
> > > On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> > > > Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday.
> > >
> > > I've seen this eventuality addressed on an L-23 by putting a ziptie around the gear lowering handle.
> >
> > all of the club retracts I've flown have had the handle disabled, either with a ziptie or with safety wire
>
> Disabling an aircraft control sounds not only insane but likely also illegal.
>
> Mike

Slightly off topic but has entertainment value: Go tell that that to the mechanic who services the local CAP L23 and routinely safety-wires the canopy emergency jettison lever with SS-wire rather than thin copper wire which one could break .....

[GM]

On Friday, May 15, 2015 at 2:59:26 PM UTC-4, Bill D wrote:
> Lets say you are deploying a retractible gear glider in a club with members who some might suspect of landing the thing gear-up someday. (Of course, you private owners never land gear-up...) Is there a way to minimize the damage when the inevitable day arrives?
>
> Maybe. One of my favorite materials is UHMW-PE - a plastic with many superlative characteristics including astonishing abrasion resistance and a very low coefficient of friction. A 9mm thick strip, 150mm wide might very well withstand a gear-up landing of an 850 kg glider. It's also very light, cheap and a shade of white closely matching gel-coat.
>
> Until recently, there was no way to glue this stuff to anything even itself but new epoxy adhesives have appeared on the market that advertize the ability to stick it to almost anything including fiber reinforced composite epoxy structures like glider belly's and wing tips.
>
> So, obviouisly, some testing is in order before slapping a strip of UHMW-PE on the belly of your glider. A test rig on a pick-up's reciever hitch could slam a patch of it down on a concrete runway to simulate a gear-up. Anybody interested?

Bill,
3M offers a very thick PU-film tape used on the leading edge of helicopter blades and wind turbine blades (leading edge erosion tape). The adhesive is very sticky - I had it on the belly of my glider for 20+ years and it protected it from stone chips aft of the landing gear and an intentional gear-up landing in a freshly prepared cotton field. One could apply several layers for a 850kg ship.
Uli

[Jonathan St. Cloud]

>
> I've always presumed that real aviators can fly their aircraft and listen to the radio at the same time. If a "check gear" call rattles a pilot so that he loses control of the glider, there's a problem afoot much more serious than radio procedures.

I agree! If I was going to land gear up would be nice to have a radio call from someone who noticed, I can certainly fly and listen to the radio. Hell, I even had tower tell me I was on fire right after I got in the air, no reason to crash. Once I did almost land gear up was flaring when I heard a call "gear" lowered the gear just in time, was low enough I scrapped the forward corner of both gear doors. Fly the aircraft and deal with the issue, no reason to have a moratorium on alerting a pilot on final. If the pilot does not have the skills to fly and solve a problem he should just fly then and maybe take up tennis.

On a related point, checklists. Whether I am flying the Grob (fixed gear) or the Nimbus, I use the same checklist before every landing. Used a check list in the Turbo prop too.

[Per Carlin]

There are two kinds of glider pilots:
- Those of us that has landed gear up (and will eventually do it again).
- And those of you who has not done done it, yet.

When it comes to calling "gear up" on the radio do you have to bear in mind that cockpits in gliders are differently designed. On SH are the gear leveler on the right side and has to be pushed forward. So to extract the gear on short final means that you have to push the brake forward into locked position, change from right hand to left for the stick and then maneuver the gear with the right. On old SH is the force for maneuver the gear leveler significant and it is nog uncommon that you pull the stick backwards. You are now on a really short final with the stick in wrong hand, high nose attitude and no hand on the airbrake. Most of the time can we handle this, but sometimes is the stress to much. Before you call "gear up" on final in the radio do you therefore need to know:
- Is the pilot mentally capable of the stress right now?

My almost first gear up landing was in a Discus, someone called "Gear up" on short final and it was close to be the last landing of that Discus.
My first gear up landing was in a LS1-f on bitumen, a big surprise for me that glider hit ground 2dm lover than expected and big amusement from the surroundings. It took med less than 3h in the workshop the same day to repair the damage and the glider was ready for competition the next day.

When it happens again do I prefer the gear up scenario, even on a hard surface than fiddling with gear leveler on low altitude with a potential wreckage.

[Bob Whelan[_3_]]

>> I've always presumed that real aviators can fly their aircraft and listen
>> to the radio at the same time. If a "check gear" call rattles a pilot so
>> that he loses control of the glider, there's a problem afoot much more
>> serious than radio procedures.
>
> I agree! If I was going to land gear up would be nice to have a radio call
> from someone who noticed...<snip>...no reason to have a moratorium on alerting a pilot on
> final...

In this case: "moratorium" = "catering to the lowest common denominator".
First priority: Fly the stinking sailplane! Second priority?: (If you must...)
Abuse it as gracefully as possible under the circumstances.

Head shakingly,
Bob W.

[Tango Whisky]

From where I fly:
- glider w/ gear up turning into final / on long final: Be nice and give him a radio call
- glider (still?) w/ gear up on short final: Leave him alone. Make sure that the beer is in the cooler.

Biggest damage will be the one to the driver's ego.
Someone who is too distracted to prepare for landing will most probably fail to react to a buzzer or other onboard alarms, so I don't see the point of these gadgets.
And somebody who just forgot to do the check - well, he won't next time.

[Mike the Strike]

The best idea I came across some years ago was at a flight school that trained in both fixed gear and retractable single-engine. The fixed-gear planes had a panel switch labeled "gear" with a red and green light. Gear down and locked was taught on every single flight in all their ships and became part of "muscle memory".

Mike

[Bill D]

On Monday, May 18, 2015 at 1:55:27 AM UTC-6, Per Carlin wrote:

> When it comes to calling "gear up" on the radio do you have to bear in mind that cockpits in gliders are differently designed. On SH are the gear leveler on the right side and has to be pushed forward. So to extract the gear on short final means that you have to push the brake forward into locked position, change from right hand to left for the stick and then maneuver the gear with the right. On old SH is the force for maneuver the gear leveler significant and it is nog uncommon that you pull the stick backwards. You are now on a really short final with the stick in wrong hand, high nose attitude and no hand on the airbrake. Most of the time can we handle this, but sometimes is the stress to much. Before you call "gear up" on final in the radio do you therefore need to know:
> - Is the pilot mentally capable of the stress right now?

I fly an old S-H glider and this falls under the heading of basic airmanship. Switching hands on the stick is SOP for many operations. It behooves one to learn how to do it while flying accurately.

[Tango Whisky]

Le lundi 18 mai 2015 17:46:31 UTC+2, Bill D a écrit*:
> On Monday, May 18, 2015 at 1:55:27 AM UTC-6, Per Carlin wrote:
>
> > When it comes to calling "gear up" on the radio do you have to bear in mind that cockpits in gliders are differently designed. On SH are the gear leveler on the right side and has to be pushed forward. So to extract the gear on short final means that you have to push the brake forward into locked position, change from right hand to left for the stick and then maneuver the gear with the right. On old SH is the force for maneuver the gear leveler significant and it is nog uncommon that you pull the stick backwards. You are now on a really short final with the stick in wrong hand, high nose attitude and no hand on the airbrake. Most of the time can we handle this, but sometimes is the stress to much. Before you call "gear up" on final in the radio do you therefore need to know:
> > - Is the pilot mentally capable of the stress right now?
>
> I fly an old S-H glider and this falls under the heading of basic airmanship. Switching hands on the stick is SOP for many operations. It behooves one to learn how to do it while flying accurately.

Switching hands on the stick while working the airbrakes on short final is no SOP at all.

Bert
Ventus cM TW

[son_of_flubber]

On Monday, May 18, 2015 at 2:41:06 AM UTC-4, Jonathan St. Cloud wrote:
> >
> > I've always presumed that real aviators can fly their aircraft and listen to the radio at the same time.

Fly with the pilots that you have, not the pilots that you would like to have. The notable number of fatal accidents attributed to pilot panic and/or misstep triggered by a panicky radio call is evidence that radio calls on short final (and takeoff) are rather risky. Some of those accidents involved very seasoned pilots.

You'll never know which pilot will be distracted until it happens. It might be a low hours pilot, or it might be a high hours pilot that is tired or past his prime (or both). That the gear is up or the tail dolly left on in the first place is a clear indication of pilot brain fart, and one brain fart flags the risk of an adverse reaction to a radio call.

The BGA rule against this sort of radio call is an interesting counter balance to the consensus of RAS pundits in favor of short final/takeoff radio calls.

A pilot who is not sure how he would react has the option of turning off his radio at some point.

[Jonathan St. Cloud]

Also a pilot that does not have the skills to address the emergency at low altitude has the option of just landing gear up. I am of the belief knowledge is good, what you do with it is TOTALLY up to you.

[[email protected]]

On Monday, May 18, 2015 at 12:58:45 PM UTC-7, Jonathan St. Cloud wrote:
> Also a pilot that does not have the skills to address the emergency at low altitude has the option of just landing gear up. I am of the belief knowledge is good, what you do with it is TOTALLY up to you.

The pilot also has to realize that he doesn't have the skills to handle the situation and ignore the radio call, something that may not be obvious on short final after after a 5+ hour flight, possibly while suffering from dehydration, mild hypoxia, hunger, and/or needing to pee. I'm always surprised at the number of pilots in these threads that have apparently never made a single mistake in their flying careers, I wish I was that perfect...

[PBA]

Back on topic...is there good material to protect the underbelly of a sailplane?
I would be interested in protecting the base of the wing spar opening on the fuselage. Years of assemblies have started to wear a groove and it's getting thin. Something Teflon Based? I see from a previous post, not an easy material to bond to something else.

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

On Monday, May 18, 2015 at 5:38:43 PM UTC-4, PBA wrote:

> I would be interested in protecting the base of the wing spar opening on the fuselage. Years of assemblies have started to wear a groove and it's getting thin. Something Teflon Based? I see from a previous post, not an easy material to bond to something else.

UHMWPE or the material from gap seals (and using GOOD double stick tape for either) makes a good "wear material" for the bottom of the spar box carry through. Something on the order of 0.040" is fine, biggest thing is to NOT go so thick that you remove the clearance between the box & the spar bottom..
Of course, lifting the wing all the way in is free, some sort of protection is worth it.

[PBA]

Charlie,
Thanks for your reply. I have some gap seal tape. I may try that. I do my best to keep the spar up, but the damage has been done over the past 30 years...

[[email protected]]

Most gliders come with a sacrificial layer for protection. It is called rubber and it is on a little round thing tat you lower before landing. Checklists and mindfulness keep this thing as the number one protection against damage while landing! You could also install a steel plate but why, just use the wheel. Now the glide computers, independent micro switches and checklists are all guards against somehow forgetting to put the ship in landing configuration.

One poster wrote that radio warnings to a pilot on final is prohibited, really? If the verbal memonic check and the gear warning system were not working, I would want to know if my gear was up. I can fly and think, if I can safely lower the gear I would and have very low. If someone radioing you that your gear is up causes you to crash, the cause was not the radio transmission rather the pilot's failure to adequately aviate. If we adjust all radio transmissions for the absolutely lowest possible "skill" level, maybe we should require a higher skill level. I know accidents happen, but this is one that is avoidable with two checks before the radio transmission.

[Mark628CA]

I heard of (but did not witness) an account of a pilot who forgot the gear in his glider, touched down several inches lower than recommended and had the presence of mind to pull back on the stick, simultaneously closing the spoilers, floated high enough to lower and lock the undercarriage, redeploy the spoilers and land with a normal rollout and stop. VERY minor damage to the belly of the glider. One can only hope that such presence of mind will occur to me when I (probably inevitably) screw up. Something to keep in mind- if you have some speed, are completely familiar with your aircraft and things are going to hell with grindy noises that will probably cost $300 per second, maybe a last minute save is possible. We have all landed, closed the spoilers and floated again, so a reasoned, planned and perhaps practiced response might give you enough time to get the round rubber thing out. Just a thought. Obviously a last chance scenario that should not replace proper training on landing checklists.

[Jonathan St. Cloud]

Mindfulness actions keep most accidents from happening. I was flying in the co-pilot seat of a high performance twin and saw the pilot check the gear lights, he had green, but did not bother to count. He need three green not two. He was mindlessly going through a landing checklist. I was mindfully flowing the check list. It is always best to actually include the brain not do by muscle memory alone.

On Saturday, May 16, 2015 at 9:42:47 AM UTC-7, wrote:
> So you think having 3 green lamps in every real airplane is not a good idea to prevent landing on it's belly?
>
> And when you deploy spoilers on the beginning of final lets say 300 AGL there is lots of time to put the gear down without geting panict by a "beep"..
> But I would also prefer the voice module...

[Mark628CA]

Muscle memory has gotten me in trouble on occasion. Primarily with the actions of opening and consuming bottles of beer in rapid and repeated succession.

[bumper[_4_]]

On Monday, May 18, 2015 at 2:38:43 PM UTC-7, PBA wrote:
> Back on topic...is there good material to protect the underbelly of a sailplane?
> I would be interested in protecting the base of the wing spar opening on the fuselage. Years of assemblies have started to wear a groove and it's getting thin. Something Teflon Based? I see from a previous post, not an easy material to bond to something else.

The material for that is UHMW PE tape, available in various thicknesses and widths, with either rubber or acrylic adhesive. Common thickness ranges from about .005" to .020". Available from McMaster-Carr or Amazon etc.

Note that as you approach 10 mills, the tape starts getting more rigid and is suitable mostly for flatter surfaces. For lining the fuselage spar openings, you'll want .005" (or there'bouts, and acrylic adhesive).

UHMW PE is almost as slick as Teflon, but has much higher mechanical strength. Teflon, will slippery, is not nearly as wear resistant or useful as an anti-abrasion liner. For tough jobs, UHMW is best.

bumper
I probably have a dozen rolls of UHMW PE in various calibers in my hangar :d)

[Gavin Short[_2_]]

At 01:48 19 May 2015, bumper wrote:
>On Monday, May 18, 2015 at 2:38:43 PM UTC-7, PBA wrote:
>> Back on topic...is there good material to protect the underbelly of a
>sa=
>ilplane?=20
>> I would be interested in protecting the base of the wing spar opening
on
>=
>the fuselage. Years of assemblies have started to wear a groove and it's
>ge=
>tting thin. Something Teflon Based? I see from a previous post, not an
>easy=
> material to bond to something else.
>
>The material for that is UHMW PE tape, available in various thicknesses
>and=
> widths, with either rubber or acrylic adhesive. Common thickness ranges
>fr=
>om about .005" to .020". Available from McMaster-Carr or Amazon etc.=20
>
>Note that as you approach 10 mills, the tape starts getting more rigid
and
>=
>is suitable mostly for flatter surfaces. For lining the fuselage spar
>openi=
>ngs, you'll want .005" (or there'bouts, and acrylic adhesive).
>
>UHMW PE is almost as slick as Teflon, but has much higher mechanical
>streng=
>th. Teflon, will slippery, is not nearly as wear resistant or useful as
an
>=
>anti-abrasion liner. For tough jobs, UHMW is best.=20
>
>bumper
>I probably have a dozen rolls of UHMW PE in various calibers in my hangar
>:=
>d)
>
My friend and I had this problem on our gliders, a DG200 and Std Cirrus
respectively. Measure the depth of the groove. Lay up several sheets/strip
of
glass fibre on a layer of plastic sheet on a workbench. When cured cut to

length, check the strip fits the groove and brings the level of the unworn
part
of the fuselage. Attach in place with resin. When the resin has cured
file/sand
to a smooth finish, less than 10 minutes work each side. Result is a
durable
smooth surface for the spar to slide into the fuselage at the right height

bringing joy back to rigging again. An inspector checked our handy work
and
was most impressed. I may have to repeat again in another 1500
assemblies/43 years!

Gavin
Std Cirrus, G-SCNN, #173
SFV Südeifel, Utscheid, Germany

[[email protected]]

Hi Bumper
Please send me two feet of this material to fit the spar s

[bumper[_4_]]

On Wednesday, May 20, 2015 at 3:01:47 PM UTC-7, wrote:
> Hi Bumper
> Please send me two feet of this material to fit the spar s

I'll include a couple of feet with your order of a MKIV "high tech" yaw string (it will be folded to fit in an envelope, offer good through 21 May 15 :c).

Or, you can get your very own roll on Amazon ($6.02 w/free shipping w/"Prime") 5 yds, 3/4" wide, .007" thick.

http://www.amazon.com/TapeCase-423-5-UHMW-Tape-5yds/dp/B00823JEUO/ref=sr_1_1?ie=UTF8&qid=1432181659&sr=8-1&keywords=uhmw+tape#product-description-iframe

[[email protected]]

Anybody who knows Bumper personally know he has "several rolls" of just about everything in his hangar. Which is a good thing, I might add.