Do L'Hotellier Ball Fittings Wear?

[Casey[_2_]]

Just wondering if L'Hotellier fittings wear? I can't seem to find what the tolerance is for the ball diameter. Just curious.

I am aware of the min travel of the locking plate of 2mm.

Thanks
Casey

[James Thomson[_2_]]

At 11:04 13 April 2016, Casey wrote:
>Just wondering if L'Hotellier fittings wear? I can't seem to find what
the
>tolerance is for the ball diameter. Just curious.
>
>I am aware of the min travel of the locking plate of 2mm.
>
>Thanks
>Casey
>
L'Hotellier don't specify a limit on the diameter itself, they specify a
limit on out-of-round. Their directions are:
"The variation between several measures of the ball diameter must not
exceed 0.1 mm.
This check aim is to detect abnormal ball wear"

You should be able to download L'Hotellier's instructions from the
internet - they usually form part of the ADs issued on this equipment!

Jim Thomson

[Jonathan St. Cloud]

Yes, they wear. Ask the driver of the Nimbus 4 M in Washington that crashed on takeoff due to a worn l'hotellier Coming off the ball due to wear.

[krasw]

They do not wear if kept clean and lubricated. My fittings have exactly same dimensions as 1000 hrs ago. Bare metal against metal with some dirt between and yes, they most likely wear.

[Tango Eight]

On Wednesday, April 13, 2016 at 7:46:43 AM UTC-4, Jonathan St. Cloud wrote:
> Yes, they wear. Ask the driver of the Nimbus 4 M in Washington that crashed on takeoff due to a worn l'hotellier Coming off the ball due to wear.

Guess embarrassment overcame concern for other aviators then... no NTSB report found. I want to know how it was proven that a properly assembled, safetied & pre-flight inspected l'hotellier failed as you say. I'd also like to know if some astounding number of flight hours was involved and if anything unusual pertained to the service history (e.g. stored in Pacific Surf, lubricated with silicon carbide lapping compound, 3000 & 6000 hr life extensions pencil whipped by village idiot, you know, all the usual stuff).

Serious question btw.

Evan Ludeman / T8

[Casey[_2_]]

Thanks for the comments.

I'm wonder what the dimensions of the balls are new.

My aileron balls on both wings are 0.02 mm smaller than the spoiler balls on both wings. Dimensions are same on each wing.

What is best lubricant? Thicker grease or thiner spray? I know the pro and cons of each but just wonder others thoughts.

Casey

[Tango Eight]

On Wednesday, April 13, 2016 at 8:51:56 AM UTC-4, Tango Eight wrote:
> On Wednesday, April 13, 2016 at 7:46:43 AM UTC-4, Jonathan St. Cloud wrote:
> > Yes, they wear. Ask the driver of the Nimbus 4 M in Washington that crashed on takeoff due to a worn l'hotellier Coming off the ball due to wear.
>
> Guess embarrassment overcame concern for other aviators then... no NTSB report found. I want to know how it was proven that a properly assembled, safetied & pre-flight inspected l'hotellier failed as you say. I'd also like to know if some astounding number of flight hours was involved and if anything unusual pertained to the service history (e.g. stored in Pacific Surf, lubricated with silicon carbide lapping compound, 3000 & 6000 hr life extensions pencil whipped by village idiot, you know, all the usual stuff).
>
> Serious question btw.
>
> Evan Ludeman / T8

Okay, with a little PM assistance from Jonathon (thanks Jonathon) I was able to find the NTSB report. I had searched on manufacturer plus Washington state and the NTSB has the manufacturer misspelled in this accident report.

As far as the NTSB is concerned, it's failure to properly assemble and preflight, so admitted by the pilot.

best,

Evan Ludeman / T8

[Tango Eight]

On Wednesday, April 13, 2016 at 9:52:03 AM UTC-4, Tango Eight wrote:

> NTSB has the manufacturer misspelled in this accident report.

lol, I'm the idiot in a hurry with a worn out keyboard. *I* got it wrong in my initial search, but still got results and didn't catch my mistake.

oops.

I'm more careful at assembly time (good thing, eh?).

best,
Evan / T8

[Casey[_2_]]

L'Hotellier web site has little info. An email to them and I was sent the maintenance Instruction.

https://www.dropbox.com/s/ii53drru82a5jgu/IMA10_01-00.pdf?dl=0

Casey

[Casey[_2_]]

L'Hotellier web site has little info. An email to them and I was sent the maintenance Instruction.

https://www.dropbox.com/s/ii53drru82a5jgu/IMA10_01-00.pdf?dl=0

And it appears if the protrusion of locking lever is less than 2mm indicates the balls need replacing and I think I would replace the connectors as well.

Casey

[Casey[_2_]]

L'Hotellier web site has little info. An email to them and I was sent the maintenance Instruction.

https://www.dropbox.com/s/ii53drru82a5jgu/IMA10_01-00.pdf?dl=0

Casey

[[email protected]]

I use spray lube to annual time. Work the sliding cylinder with something soft (like a brass key) and drown it with lube as you work it several times, until everything works easily, then wipe off excess spray and she's good to go for another year.
JJ

[JS]

The Gliding Federation of Australia requires that L'Hotellier balls be replaced at some specified interval. They had to be replaced on my N3 when it was registered there. Tried to look up the GFA AD for details but their search engine doesn't find it.
The ball is inexpensive. If you need to replace the other part.... Not so.
It's a miniature trailer ball. Have a look at the trailer hitches on a few vehicles to see if they wear.
Jim

[Eric Munk]

At 15:57 13 April 2016, JS wrote:
>The Gliding Federation of Australia requires that L'Hotellier balls be
>replaced at some specified interval. They had to be replaced on my N3
when
>it was registered there. Tried to look up the GFA AD for details but
their
>search engine doesn't find it.
>The ball is inexpensive. If you need to replace the other part.... Not
so.
>It's a miniature trailer ball. Have a look at the trailer hitches on a
few
>vehicles to see if they wear.
>Jim


The interval recommended by L'Hotellier (and taken over by several national
authorities as mandatory) is ten years or 3000 hours (whichever comes
first). Most manufacturers of aircraft who use L'Hotellier balls have
specified their replacement during the 3,000 and 6,000 hours and so
intervals. IIRC Schempp-Hirth has closer intervals (500 hours?) due to them
being fitted in a different way and they have had threaded ends fail.

[PGS]

On Wednesday, April 13, 2016 at 9:06:58 AM UTC-4, Casey wrote:
> Thanks for the comments.
>
> I'm wonder what the dimensions of the balls are new.
>
> My aileron balls on both wings are 0.02 mm smaller than the spoiler balls on both wings. Dimensions are same on each wing.
>
> What is best lubricant? Thicker grease or thiner spray? I know the pro and cons of each but just wonder others thoughts.
>
> Casey

I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.

[Casey[_2_]]

>
> The interval recommended by L'Hotellier (and taken over by several national
> authorities as mandatory) is ten years or 3000 hours (whichever comes
> first). Most manufacturers of aircraft who use L'Hotellier balls have
> specified their replacement during the 3,000 and 6,000 hours and so
> intervals. IIRC Schempp-Hirth has closer intervals (500 hours?) due to them
> being fitted in a different way and they have had threaded ends fail.

Erik,
Where do see that L'Hotellier recommends ten yrs or 3000 hrs? Also my glider manufacturer has no mention of this in the life extensions.
I emailed them this morning and all they sent me was the maintenance instruction and there is no mention in that of this recommendation.

[Casey[_2_]]

> >
> > Casey
>
> I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.

pgs.
The balls are not out of round, just different between spoiler and aileron. But now I'm thinking these balls are of different diameter to begin with, a closer look, the stem to the ball is longer on those that are the 0.02 smaller.

Casey

[Casey[_2_]]

>
> The interval recommended by L'Hotellier (and taken over by several national
> authorities as mandatory) is ten years or 3000 hours (whichever comes
> first). Most manufacturers of aircraft who use L'Hotellier balls have
> specified their replacement during the 3,000 and 6,000 hours and so
> intervals. IIRC Schempp-Hirth has closer intervals (500 hours?) due to them
> being fitted in a different way and they have had threaded ends fail.

Eric,
Where do see that L'Hotellier recommends replacement at ten yrs or 3000 hrs? Also my glider manufacturer has no mention of this in the life extensions. But does mention that maintenance must be done at each annual or 500 hrs for spherical.

I emailed L'Hotellier this morning and all they sent me was the maintenance instruction and there is no mention in that of the replacement recommendation.

Casey

[Bruce Hoult]

On Thursday, April 14, 2016 at 8:53:54 AM UTC+12, Casey wrote:
> > >
> > > Casey
> >
> > I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.
>
> pgs.
> The balls are not out of round, just different between spoiler and aileron. But now I'm thinking these balls are of different diameter to begin with, a closer look, the stem to the ball is longer on those that are the 0.02 smaller.
>
> Casey

Are the size differences large enough to prevent a control surface being connected to the wrong control lever? (assuming such a thing was geometrically possible)

[Casey[_2_]]

On Wednesday, April 13, 2016 at 5:16:36 PM UTC-4, Bruce Hoult wrote:
> On Thursday, April 14, 2016 at 8:53:54 AM UTC+12, Casey wrote:
> > > >
> > > > Casey
> > >
> > > I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.
> >
> > pgs.
> > The balls are not out of round, just different between spoiler and aileron. But now I'm thinking these balls are of different diameter to begin with, a closer look, the stem to the ball is longer on those that are the 0.02 smaller.
> >
> > Casey
>
> Are the size differences large enough to prevent a control surface being connected to the wrong control lever? (assuming such a thing was geometrically possible)

Bruce,
Not possible. But the spoiler ball has a longer neck and is designed that way.

Casey

[Ben Coleman]

In Australia AD177 covers L'hotellier couplings. 1000hr replacement for shanks under 6mm, 3000hr for others on flap and dive brake circuits. 0.1mm max difference between different axes of ball at 90 degrees to each other - like an X through the cross section (best to look at the diagram!). Lubrication each rigging, 50hrs and 6 months. There's a bunch of other stuff in there too, but not sure how much is Oz specific vs out of manufacturer ADs.

Cheers Ben

[Ben Coleman]

Reply to myself - most of that is in the previously linked L'hotellier maintenance instructions. My post was incorrect, replace all balls at 10yrs/3000hrs.

Cheers Ben

On Thursday, 14 April 2016 09:22:43 UTC+10, Ben Coleman wrote:
> In Australia AD177 covers L'hotellier couplings. 1000hr replacement for shanks under 6mm, 3000hr for others on flap and dive brake circuits. 0.1mm max difference between different axes of ball at 90 degrees to each other - like an X through the cross section (best to look at the diagram!). Lubrication each rigging, 50hrs and 6 months. There's a bunch of other stuff in there too, but not sure how much is Oz specific vs out of manufacturer ADs.
>
> Cheers Ben

[JS]

Ben, it was probably the 10 year thing that Camden Sailplanes flagged my Nimbus on.
Jim

[krasw]

I have never heard of anyone replacing l'Hotelliers after 10 years (or any other interval). The annual check with measurements tells you when to replace them, if ever. That's condition-based maintenance, or CBM for those who love TLAs.

[Ben Coleman]

On Thursday, 14 April 2016 17:43:19 UTC+10, krasw wrote:
> I have never heard of anyone replacing l'Hotelliers after 10 years (or any other interval). The annual check with measurements tells you when to replace them, if ever. That's condition-based maintenance, or CBM for those who love TLAs.

RBM down here.

Cheers Ben

[Eric Munk]

In the maintenance instructions from l'Hotellier (attached in
http://www2.lba.de/dokumente/lta/1993-001.pdf pages 11 and 12)

At 20:47 13 April 2016, Casey wrote:
>
>>
>> The interval recommended by L'Hotellier (and taken over by several
>national
>> authorities as mandatory) is ten years or 3000 hours (whichever comes
>> first). Most manufacturers of aircraft who use L'Hotellier balls have
>> specified their replacement during the 3,000 and 6,000 hours and so
>> intervals. IIRC Schempp-Hirth has closer intervals (500 hours?) due to
>them
>> being fitted in a different way and they have had threaded ends fail.
>
>Erik,
>Where do see that L'Hotellier recommends ten yrs or 3000 hrs? Also my
>glider manufacturer has no mention of this in the life extensions.
>I emailed them this morning and all they sent me was the maintenance
>instruction and there is no mention in that of this recommendation.
>

[Eric Munk]

At 07:43 14 April 2016, krasw wrote:
>I have never heard of anyone replacing l'Hotelliers after 10 years (or
any
>other interval). The annual check with measurements tells you when to
>replace them, if ever. That's condition-based maintenance, or CBM for
those
>who love TLAs.
>

Measuring them will indicate wear, not fatigue. On some types of gliders
fatigue has been an issue, especially when not properly lubricated, with
threaded ends breaking off from the control rod. Typically gliders where
the ball is on a 90-dgree angle to the socket and not in line with it.

National interpretations of the factory recommended replacement vary from
country to country.

[krasw]

On Thursday, 14 April 2016 14:00:09 UTC+3, Eric Munk wrote:
> Measuring them will indicate wear, not fatigue. On some types of gliders
> fatigue has been an issue, especially when not properly lubricated, with
> threaded ends breaking off from the control rod. Typically gliders where
> the ball is on a 90-dgree angle to the socket and not in line with it.
>
> National interpretations of the factory recommended replacement vary from
> country to country.


Which types are these? I have a glider that has only 90 degree joints.

If national authorities turn expression "recommended" into "mandatory", I would call that something else than interpretation.

[ND]

no spray grease. huge mess. gentlemen never use it.

On Wednesday, April 13, 2016 at 9:06:58 AM UTC-4, Casey wrote:
> Thanks for the comments.
>
> I'm wonder what the dimensions of the balls are new.
>
> My aileron balls on both wings are 0.02 mm smaller than the spoiler balls on both wings. Dimensions are same on each wing.
>
> What is best lubricant? Thicker grease or thiner spray? I know the pro and cons of each but just wonder others thoughts.
>
> Casey

[Eric Munk]

At 12:18 14 April 2016, krasw wrote:

>If national authorities turn expression "recommended" into "mandatory", I
>would call that something else than interpretation.

Welcome to Europe, where this is how EASA-rules are interpreted by most
national authorities' legal experts. Australia too, and I believe New
Zealand.

[krasw]

On Thursday, 14 April 2016 21:30:07 UTC+3, Eric Munk wrote:
> At 12:18 14 April 2016, krasw wrote:
>
> >If national authorities turn expression "recommended" into "mandatory", I
> >would call that something else than interpretation.
>
> Welcome to Europe, where this is how EASA-rules are interpreted by most
> national authorities' legal experts. Australia too, and I believe New
> Zealand.

I live in EASA-world and our authorities did their "interpretation" process to these same l'Hotellier papers before accepting them as a part of my glider maintenance program. While letting 10 year replacement recommendation slip past their fingers, they did note that l'Hotellier annual measurement has to be made by aircraft mechanic with calibrated shop instrument, since papers did not specify that owner can do it (that is actually true and is not subject to interpretation). I still know of no owner who doesn't do it himself. That is the beauty of EASA, you write fancy documents (and pay for get them approved) and then continue to act like they don't exist at all. And no one gives a sh*t.

[Tango Whisky]

Exactly.

Bert
Ventus cM "TW"

[Eric Munk]

Same here in my country: the annual measurements should IMHO be
Pilot-Owner-Maintenance, but they are not.

I think your grievances with EASA are echood throughout the general
aviation community. From my experience as an inspector there is a growing
gap between the real world and the paperwork of some aircraft offered for
inspection, in order to comply with regulations. Timeconsuming,
counterproductive to the improvement of safety and in many cases absolutely
unnecessary. Not a position any aircraft owner or pilot should be finding
himself in...

Back to the l'Hotelliers in EASA-aircraft: unless there is a national AD
out that says otherwise, the aircraft maintenance program follows only the
aircraft manufacturers recommendations and maintenance requirements. This
means there's usually a away around the 10-yearly replacement. Sometimes
around the 3,000-hours one too, but most manufacturers have taken this up
in their 3,000-hours inspection of the aircraft (not a bad thing me
thinks).

At 05:31 15 April 2016, krasw wrote:
>On Thursday, 14 April 2016 21:30:07 UTC+3, Eric Munk wrote:
>> At 12:18 14 April 2016, krasw wrote:
>>=20
>> >If national authorities turn expression "recommended" into
"mandatory",
>=
>I
>> >would call that something else than interpretation.
>>=20
>> Welcome to Europe, where this is how EASA-rules are interpreted by most
>> national authorities' legal experts. Australia too, and I believe New
>> Zealand.
>
>I live in EASA-world and our authorities did their "interpretation"
>process=
> to these same l'Hotellier papers before accepting them as a part of my
>gli=
>der maintenance program. While letting 10 year replacement recommendation
>s=
>lip past their fingers, they did note that l'Hotellier annual measurement
>h=
>as to be made by aircraft mechanic with calibrated shop instrument, since
>p=
>apers did not specify that owner can do it (that is actually true and is
>no=
>t subject to interpretation). I still know of no owner who doesn't do it
>hi=
>mself. That is the beauty of EASA, you write fancy documents (and pay for
>g=
>et them approved) and then continue to act like they don't exist at all.
>An=
>d no one gives a sh*t.
>