Jerry,
You are not alone and not living dangerously, as it seems you have a
well built reliable gear. However the non mandatory mod 51 arm helps
keep the stress down on the three bolts in the retraction arm.
Eventually, through trailering, rough air, rough airstrips and countless
landings you may experience trouble. If the arm flexes at the
connection to the LG08 it may be difficult to lower the gear and it may
require you to unload the aircraft to near negative G to flop the gear
handle out of the slot. On takeoff, you may find that the gear will not
lock up properly. Extending the gear may leave the LG08 mechanism at
less than vertical. Looseness at this joint will progress rapidly
through normal use as the gear has no over center lock per say and will
bend at its pivot points slightly both up and down, exacerbating the
problem.
Even with mod 51, if the gear is not perfectly vertical from LG8 down,
the gear handle takes the load. That dog leg in the gear handle with
the bends will flex over time, causing a higher than anticipated tension
load on the Mod 51 diagonal brace. We'll have a material and proper
dimensions to use for the arm soon. We all used Home Depot aluminum on
previous builds and I should have questioned it, but I fly a trigear and
rarely get a monowheel of significant age in the shop. No one reported
the problem so it was unknown to me until now.
I would recommend one look at his retractable gear carefully on his
annual, and at 5 years or 500 landings do a full inspection and rebuild.
Call me conservative in a liberal world, but the bushings and landing
gear block take a beating and are never cared for (I hate that dirty
hole..). All the retractable gear certified planes I have experience
with require not just a retraction check but a complete check of the
bearings and bushings annually, slop and play are defined in the
maintenance manual for the aircraft. Why shouldn't we do the same
thorough inspections and replace known wear points at a specific time to
preclude future problems.
Klaus and I discussed time changing out the following:
At 5 years or 500 landings,
Replace the bungee.
Wheel bearings KLNJ 1 1/2 They are sealed bearings, and I haven't seen
a failure but why wait until they break.
Brake pads (inspect caliper for corrosion)
Upper and lower bushings AIC 060816/AIC 060820. Inspect annually for
play and replace if detected and replace at 5 years anyway.
Inspect Mod 51 arm for wear and replace as necessary
Inspect shock absorbers and rubber block. If it hops like a bunny,
change the shocks, if it sits low, change the block. I don't know how
low, low is, but the block is about 70mm on an empty mono, so if it has
lost 10 mm in height since new, it probably needs replacing.
Look at the long bolts Euro 26 and pins LG 04 for deformation, replace
as necessary
Change the outrigger legs, inspect the pivot points and the locking
mechanism for corrosion and wear. Remove and replace as necessary.
Replace the outrigger tires/wheels if worn.
I do not have a checklist for how I check the mono gear for play, and
frankly just look at the mechanics as I do not own one... I support the
aircraft, push on the lower arm and watch the mechanism when down,
especially the locking arm. Look at the LG 04 pin and support for
cracks and wear. Any deformations of the gear requires replacement.
Then partially retract the gear and check for play in the joints, wiggle
the arms to check for play, and pivot points for play (nasty dirty job),
and finally lock the gear up and check movement of the gear mechanism by
pushing up on the gear and using my bore scope to see if there are
problems. I have never removed the mod 51, but I have also never worked
on a high time mono. As for the outriggers, I have to look at the book
if I have to take one apart just to figure how to put it back together.
I make sure that the gear leg locks down and that the flap moves through
the proper number of degrees before unlock. I was not familiar with the
Europa Club bushing mod many of you had on the outriggers until Jim
Butcher led me through one. I have only seen the standard factory
build. If there is a comprehensive checklist other than the FAA
condition inspection, I'd like to see one for my own education.
Sorry to be so long winded.
Bud Yerly
----- Original Message -----
From: Jerry Rehn<mailto:rehn@rockisland.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Tuesday, July 13, 2010 9:18 PM
Subject: RE: Europa-List: Check your Landing Gear Retraction Lever
Strut (Mod 51)
Bud
I have not installed Mod 51 and have been flying with lots of landings
for 10 years, am I living dangerously? I check the gear and don't see
issues but am I missing something? Am I the only one with out Mod 51?
Jerry
Mono 914
-------------------------------------------------------------------------
-----
From:
owner-europa-list-server@matronics.com<mailto:owner-europa-list-server@ma
tronics.com> [mailto:owner-europa-list-server@matronics.com] On Behalf
Of Bud Yerly
Sent: Tuesday, July 13, 2010 5:17 PM
To: europa-list@matronics.com
Subject: Re: Europa-List: Check your Landing Gear Retraction Lever
Strut (Mod 51)
Klaus and others,
Please send me pictures of your elongations or failures of the strut
for me to analyze. If you can provide the type material and thickness
also.
Normally 6061 common aluminum angle of 1.6 mm or 1/16 inch is plenty
strong enough.
Elongation of the hole at the bottom indicates slight movement of the
gear lock ,retraction mechanism (most probably in the down position) due
to not staying perfectly vertical with the gear down and eventually the
stresses from bending, as Klaus said, or from the latch slot gear
retraction arm interface bending, and or the three bolts elongation has
caused fatigue of the material or too much force on the aluminum angle
strut.
We will need some look see time to evaluate should if we go to steel
or a specific material/dimensions, time change, or what.
In the mean time, if everyone can look at their Mod 51 landing gear
retraction lever strut brace if over say 500 hours and look for wear, as
soon as you can, and low time planes on your next annual, then send me
updates, I'd appreciate it.
Many thanks,
Bud Yerly,
Europa Tech Assistance.
direct email: budyerly@msn.com<mailto:budyerly@msn.com>
or just hold control key and click below to email
via Europa website:
mailto:enquiries@europa-aircraft.com<mailto:enquiries@europa-aircraft.com
>
via Custom Flight Creations website:
mailto:mail@customflightcreations.com<mailto:mail@customflightcreations.c
om>
----- Original Message -----
From: klaus dietrich<mailto:klaus.dietrich@oracle.com>
To: Europa-List Digest Server<mailto:europa-list@matronics.com> ;
jimmy Keppert<mailto:MCA234@aon.at>
Sent: Tuesday, July 13, 2010 1:29 PM
Subject: Europa-List: Check your Landing Gear Retraction Lever Strut
(Mod 51)
Check your Landing Gear Retraction Lever Strut (Mod 51)
after 10 years in service and some 800 hours with as many landings,
my Landing Gear Retraction Lever Strut (Mod 51) had an oval oversize
hole at the bottom end (14mm; for the MS 20392-5C37 bolt which is 9,5
mm) and it finally broke at the top (just below the AN 3 bolt probably
due to some misalignment due to the play at the bottom...
no play at the top AN 3 bolt, however!
The three screws on the Landing Gear Retraction Lever at the top
seem to hold (no play)....
I'm still searching for an explanation; my aluminum angle was
probably not strong enough: material thickness: 1,5 mm; L-profile: 20 mm
x 8 mm
also the strut is not absolutely straight and there is some sideways
flexibility which may have favored the play...
Klaus
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