L'Hotelier Fitting Safety Pins

[Dan Marotta]

Those bobby pins are used extensively on my Stemme and I lost two that fell out of their retaining strings during taxiing operations leaving me with only one spare.  A quick search found 1.2 mm hitch pins at WalMart (of all places).  I got a bag of 50 pins for under $8.  Here's a link for anyone needing the same.  I've tried them and they fit.

--
Dan, 5J

[kirk.stant]

Ah yes, the aviation department of Walmart; personally I prefer McMasterCarr's aviation line, or locally the aviation branch of Rural King, but in a pinch...

Way better than Harbor Freight's aircraft parts store!

(It's just the Jack Daniels' talkin, bro! ;^)

Kirk
66

[ifee...@hotmail.com]

When a fellow ASW-15 owner in my club lost some of his pins I bought a couple dozen of the AN safety pins mentioned in the LBA AD from Aircraft Spruce. More expensive than the Walmart option but better? Not really. The Schleicher TN on the AD offers a pin part number to order from them the same style of pins you got at Walmart and says right in the TN that they are Ford parts. For some reason when my ASW-15 came over from Germany (1998) it had AN type pins on the airbrake connections (which use the up/down wedge L'Hoteliers) and the bobby pins on the ailerons (which have the rotating type L'Hoteliers). Another club member who has just bought an ASW-20 has been looking for the captive safety pins referred to in the AD as Schempp-Hirth pins - an ASW-19 in the club has them and they seem like a really good solution. So far no luck in finding a source for them.

Up here in the Great White North we frequently use the aviation department of Canadian Tire for our needs.

[Casey]

Good find and thanks Dan.
I keep safety wire in my trailer in case I loose a pin. The AD states "Enlarging the safety pin guide hole diameter to a min of 1.2mm (0.05 in.) to accommodate a safety wire or pin, as applicable.

But under that is what I wonder if anyone has done because I do not have this.

"Fabricating a placard (using ⅛ inch letters) with the following words:"

"All L'Hotellier control system connectors must be secured with safety wire, pins, or safety sleeves, as applicable, prior to operation." and

"Install this placard in the glider or sailplane within the pilot's clear view."

Casey

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

If you have not installed the placard, assuming the AD applies to your glider, you glider is not airworthy and should not have passed the last annual or condition inspection.
It's easy to do. Print it, laminate(office tape will do in a pinch) and install with double stick tape.
Easy Peasy
UH

[James Thomson]

According to LBA AD 1993-001/3 the 1.2 mm pins are Ford reference
number 1473 931

Whether Ford still supply is another matter...!

[Casey]

>
> If you have not installed the placard, assuming the AD applies to your glider, you glider is not airworthy and should not have passed the last annual or condition inspection.
> It's easy to do. Print it, laminate(office tape will do in a pinch) and install with double stick tape.
> Easy Peasy
> UH

AD97-08-06 Note 1 "This AD does not apply to gliders and sailplanes that do not have a U.S. type certificate (i.e.., experimental category); however the FAA strongly recommends compliance with the intent of this AD for airplane involved in U.S. operation where a U.S. type certificate is not necessary.

Casey

[Dan Marotta]

I don't see how a properly connected and pinned fitting could fail
unless the ball or socket was worn beyond specifications. My guess,
with absolutely no actual information, would be that there was a
material failure and something broke rather than became disconnected.
It would be interesting to see pictures or read the NTSB report. Do you
have more information about the crash?

On 10/13/2016 5:44 PM, Jonathan St. Cloud wrote:
> Was it a pinned L'Hotelier that failed on the Nimbus 4M crash in Washington? Does anyone know of failures with properly pinned L'Hotelier?
>

--
Dan, 5J

[sports...@gmail.com]

On Thursday, October 13, 2016 at 7:44:07 PM UTC-4, Jonathan St. Cloud wrote:
> Was it a pinned L'Hotelier that failed on the Nimbus 4M crash in Washington? Does anyone know of failures with properly pinned L'Hotelier?

http://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20080602X00759&key=1&queryId=f9ec9464-b0e3-46c0-8bb8-7122ee3a3d9a&pgno=1&pgsize=50

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

"Too well lubricated?"!

Lack of lubricarion leads to:
-wear on the ball and socket, increasing clearances.
-difficulty getting the lock to properly latch.

As to the original statement (quoted), maybe the ball or socket were worn beyond limits, lubing removed some "crud" that was holding things together. This then allowed a "properly pinned/locked joint to come apart".
Go back to root cause, in my "non degreed mechanical engineering opinion".

IMHO, many things need to be cleaned, looked at, lubed a few times a year, at a good annual inspection at a minimum. Reducing wear and easing use of controls/systems are a benefit.

[Dan Marotta]

According to the NDSB report: "The pilot stated that during assembly of
the glider prior to the flight, the left aileron control tuve was
inadvertently not attached, anbd that he did not verify that all flight
controls moved free and correct prior to takeoff."

That doesn't sound to me like a failure of the L'Holelier fitting.

--
Dan, 5J

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

My previous comment/post still stands.

[OHM Ω]

The glider under discussion may not allow this option but after buying my first ship (a DG-101)with L'Hotellier fittings, I quickly upgraded them with Wederkind sleeves. Very easy to use/lock. See http://aviation.derosaweb.net/wedekind/ for details.

L'Hotellier maintenance procedures from L'Hotellier Inc. can be found at; http://aviation.derosaweb.net/wedekind/documentation/L'Hotellier%20Maintenance%20IMA10_01-00.pdf. BTW: It recommends "grease", not graphite. I use http://www.super-lube.com/synthetic-multipurpose-grease-ezp-49.html.

John "OHM"

[George Haeh]

If the l'Hotellier head is not fastened to the ball, inserting the pin
won't make any difference. I was once advised to try to pull the
connector off the rod to make sure it really is on right.

It's often awkward and hard to see where the connectors are
fastened.

Once fastened and secured I like to move the rod while observing
the control surface.

[ifee...@hotmail.com]

The pins (or the other T/N and AD listed devices) can be put in place if the coupling is fully connected... or completely unconnected. On my 15 I can see the four L'Hotelliers quite well but I still first check that they're assembled properly by using the pull test and then carefully visually checking the connections. I then follow those up with a positive control check.

I have seen people get the couplings sort of "half-way connected": the wedge gets pushed down, the socket is put part way down the ball and then the wedge is released. In this situation the pins won't go in (or the Wedekinds won't slide home) so the few times I've seen it done it was always caught quickly.

One way I've theorized that the L'Hotelliers may have disconnected when not equipped with the safety devices would be if the spring loaded wedge got contaminated with enough dirt that the spring wasn't able to push it back up to lock the coupling when it was released after putting it over the ball.

[Philip Dwyer]

At 00:11 13 October 2016, Dan Marotta wrote:

I keep my pins in the strings with a small fly tying style thread wiping
and a drop of nail varnish.

[Dan Marotta]

My pins were tied tightly with waxed twine but, during taxi, the pins
just slipped out of the loops. I have taken to inserting the pins into
the holes of the fittings where they're kept safe during taxi.

Dan

--
Dan, 5J