Yes the hydro press on the gauge fluctuated, in synch with the gear as
it "chattered" on the way up. This happened at the original 1,100 psi setting
and the temporarily boosted 1,425 psi setting.
Also, in a previous post, Scott/GrayHawk suggested a sequencing valve
overhaul may be in order. Has anyone else had to overhaul or replace a
gear door sequencing valve?
Interesting problem. Did you happen to measure the hydro pressure at the
higher setting (or normal) while cycling? In other words, does the hydro
pressure remain constant throughout the cycle or does the pump pressure drop off
through the cycle?
Regards,
Dan
Sent from my Verizon Wireless BlackBerry
From: asw20747@aol.com
Date: Wed, 25 Feb 2009 08:11:45
-0500
To: <lml@lancaironline.net>
Subject: [LML]
Legacy Gear Retraction Problem
We have come up with an interesting problem while doing a recent
annual. Was wondering if anyone might have some ideas?
Background:
We have a well built and well maintained Legacy that has been flying for
about 2 years with just under 300 hrs on it. We are doing the (second) annual
inspection and on the gear swing found that the nose gear retracts first, then
the left main followed by the right main. When the right main went up it
did so it with a chatter or shudder, most noticeable, at first, with the
inner gear door. In other words, it went up but not smoothly like the
other gear or as it has ALWAYS done in the past.
In an attempt to trouble shoot the problem we disconnected the inner
gear door and checked for ease of movement, binding etc.. All was
perfectly smooth with no binding or resistance of any kind. We then
retracted the gear without the inner door connected. We still notice a
consistent chatter in the right main AND in the inner gear door actuator
cylinder, moving without the inner gear door attached. We then took the
sequencing valve out of the picture by using a piece of doweling pushed up on
the sequencing valve as the main gear retracted (inner door was
still disconnected) and now noticed a smooth operation of the gear and
the inner door actuator.
We have checked that the sequencing valve makes good solid contact with the
gear. We checked the up side hydro pressure and it was 1100 psi. We ran
this problem by Lancair technical (Ross) and he suggested we bump up
the hydro pressure to not more than 1,500 psi up to see if that made any
difference. We boosted it temporarily up to 1,425 psi nd
there were NO changes.
Does any one have an idea of what may be going on? We have
considered air in the system but with no leaks and the system operating for
quite some time with no problems and many cycles, would air in the system still
be a possibility? How about the sequencing valve, seems pretty simple,
they either work or they don't, could that be an issue? Since we have been
involved in this problem the issue has been consistent, never intermittent, and
never involved the other gear.
At this point ANY ideas or suggestions would be GREATLY
appreciated.
Erik
Legacy
N74FX