LS X gear collapse fix

[Uncle Fuzzy]

In going over some very old (15 years) RAS threads on gear collapse
problems, I found a reference to a service bulletin that mandates
replacing the gas spring with an aluminum bar. JJ also mentioned
doing the same. Alas, the 15 year old link is inoperative. On the DG
website I found a listing of service bulletins, but not the service
bulletin itself. If anyone can send me a link or explain how to
obtain the reference service bulletin, I'd be very grateful.
TIA

[[email protected]]

On Jan 28, 8:50*pm, Uncle Fuzzy > wrote:
> In going over some very old (15 years) RAS threads on gear collapse
> problems, I found a reference to a service bulletin that mandates
> replacing the gas spring with an aluminum bar. *JJ also mentioned
> doing the same. Alas, the 15 year old link is inoperative. *On the DG
> website I found a listing of service bulletins, but not the service
> bulletin itself. *If anyone can send me a link or explain how to
> obtain the reference service bulletin, I'd be very grateful.
> TIA

Have you tried emailing this question to the factory?

[JS]

Jim et al:
All LS-4 Tech Notes are on...
http://www.dg-flugzeugbau.de/Data/TM-LS/LS4/
(scroll to the bottom of the main "Technical Notes of our Aircraft"
page, don't use the LS4/4a link on the left side)
Jim

[Uncle Fuzzy]

On Jan 28, 11:07*pm, JS > wrote:
> Jim et al:
> * All LS-4 Tech Notes are on...http://www.dg-flugzeugbau.de/Data/TM-LS/LS4/
> (scroll to the bottom of the main "Technical Notes of our Aircraft"
> page, don't use the LS4/4a link on the left side)
> Jim

Thanks Jim! That's what I was looking for.

[[email protected]]

So which one is it?

[Uncle Fuzzy]

On Jan 29, 2:19*pm, wrote:
> So which one is it?

I scanned them all, and none mentions replacing the gas spring with an
aluminim bar. Technical Bulletin #6012 for the LS6 is about replacing
the gas strut with part # 4R2-111, which I believe is the
aforementioned aluminum bar. I won't name names, but at least two
people that I hold in high esteem have stated that they have done this
to other LS's.

[JJ Sinclair]

Here's the deal with LS-3/4/6/7's. When the shock absorbing gear is
under duress (as in bouncing on a rough landing), as the rear member
absorbs the up-down motion, the geometry of the gear is changing. Not
much, but enough to make the retraction rod (and therefore the retract
handle) start MOVING! This is an undesirable situation, because the
gear can collapse ( I hate it when that happens). Rolleden Snyder, in
their wisdom, delt with this by placing a gas strut in the retration
rod going to the retract handle, so now the gas strut absorbes the
slight motions and that allows the retract handle to stay snugly in
its assigned down position. Problem solved and everything was fine
until the gas struts started loosing their poop and we were right back
to the gear collapsing, only now it could collapse on a very gentle
landing. Ah ha, said RS, lets replace the gas strut with a solid bar
because the fix is worse than the disease and we'll just hope that
little handle stays where its supposed to be.

One can check the condition of ones gas strut by pushing forward on
the rear "H" member of ones landing gear as in, try to make it
collapse. It should only move about a half inch and spring right
back.................if not, one might be in for a rude surprise on
the next takeoff or landing. Oh yeah, recommend this check only be
performed with the fuselage jacked up on the trailer saddle. One other
little tid-bit, make sure the fuselage is jacked up high enough to
allow the gear to completely extend without touching the ground
or ..................see above about gear collapsing on takeoff.
Cheers,
JJ

[JS]

Good point about why the gas strut is there in the first place, JJ.
....Thought it was just for entertainment value.
Jim

[[email protected]]

Is there a suitable replacement gas strut that can be bought in the US
(McMaster??) rather than ordering from Germany?

[DRN]

On Jan 28, 11:50*pm, Uncle Fuzzy > wrote:
> In going over some very old (15 years) RAS threads on gear collapse
> problems, I found a reference to a service bulletin that mandates
> replacing the gas spring with an aluminum bar. *JJ also mentioned
> doing the same. Alas, the 15 year old link is inoperative. *On the DG
> website I found a listing of service bulletins, but not the service
> bulletin itself. *If anyone can send me a link or explain how to
> obtain the reference service bulletin, I'd be very grateful.
> TIA

Good points below, but a friend who just repaired the
following on his LS-3 reminds me...

Many of these LS gliders have rubber shock absorbing
gizmos built into the landing gear - and they are now getting
very old and turning to mush. The glider will typically sit much
lower to the ground then when new (and has less shock
absorption, wrong angle of attack on ground etc).

If the strut wasn't recently replaced, you'll want to have
a good look at that part as well !

Hope this helps,
Best Regards, Dave "YO electric"

[Uncle Fuzzy]

On Jan 30, 11:13*pm, wrote:
> Is there a suitable replacement gas strut that can be bought in the US
> (McMaster??) rather than ordering from Germany?

Last one we got was from : http://www.solairecanada.com/index2.htm
Around $80, I think.

[[email protected]]

On Jan 31, 8:34*am, DRN > wrote:
> On Jan 28, 11:50*pm, Uncle Fuzzy > wrote:
>
> > In going over some very old (15 years) RAS threads on gear collapse
> > problems, I found a reference to a service bulletin that mandates
> > replacing the gas spring with an aluminum bar. *JJ also mentioned
> > doing the same. Alas, the 15 year old link is inoperative. *On the DG
> > website I found a listing of service bulletins, but not the service
> > bulletin itself. *If anyone can send me a link or explain how to
> > obtain the reference service bulletin, I'd be very grateful.
> > TIA
>
> Good points below, but a friend who just repaired the
> following on his LS-3 reminds me...
>
> Many of these LS gliders have rubber shock absorbing
> gizmos built into the landing gear - and they are now getting
> very old and turning to mush. The glider will typically sit much
> lower to the ground then when new (and has less shock
> absorption, wrong angle of attack on ground etc).
>
> If the strut wasn't recently replaced, you'll want to have
> a good look at that part as well !
>
> Hope this helps,
> Best Regards, Dave "YO electric"

Speaking of these rubber bushings used for shock absorbing, can anyone
point me to any documentation that describes how to measure the amount
of allowable "give"? I have an LS1f and I have nothing in my
maintenance log that shows these were ever replaced. Would my energy
be better spent on just replacing them? Or is it worth finding the
information needed to measure their current condition?

By the way, my "f" does not have any gas struts any where in the
landing gear system (although some other f's do). I've never had any
issues with it, although it sure is a nice ride on the "sprung" gear.


Thanks,
Dave

[James C. Simmons]

At 07:13 31 January 2009, wrote:
>Is there a suitable replacement gas strut that can be bought in the US
>(McMaster??) rather than ordering from Germany?

I got mine from Chris Klix at Pacific Aero Sports in Arlington, WA

Jim