REFLECTOR: Nose gear doors don't close

[Al Gietzen]

Mel;

 

Based on your description it certainly sounds like it’s a sequence valve
adjustment issue.  I had to adjust mine more than once after the initial
setup. Can you see the valve stem when the gear is up to see if it is
depressed?  It has a bit of a stroke, so I’d go more than ½ turn.  The
adjusting screw has a lock nut – were you able to back that off a bit?

 

 Fortunately I was the first to install mine where the plans now call for it
to be; so adjusting is easy.  

 

I found that the adjusting screws on the pressure switches changed the ‘band
width’ between the opening and closing of the switch.  Unlikely that it is a
pressure problem since there is more than enough pressure to force the gear
all the way up. The “up” pressure switch is set for about 1050 psi., and on
my system I found that it took less than 300 psi to bring the gear up, and
there’s about that much pressure drop in the ¼” line as the gear is
traveling.  It spikes to over 1050 as the gear cylinders hit the end of
travel.

 

Hope this helps,

 

Al

 

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of PUSHERPILOT at wmconnect.com
Sent: Saturday, October 25, 2008 9:36 AM
To: reflector at tvbf.org; support at velocityaircraft.com
Subject: REFLECTOR: Nose gear doors don't close

 

While doing a pre-buy inspection on my Velocity STD RG I found that the nose
gear doors are not closing.  When I lift the gear leg by hand just a
fraction of an inch the doors close.  The gear had been tested several times
a month before during the annual condition inspection.  The airplane had not
been flown since. 

What happened in between?  The gear leg is not coming up as far or the
sequence valve changed it's adjustment, or ??  After the doors close the
gear leg seems to be in the same position it always was, slightly rubbing on
the doors.  My sequence valve is the old style on the floor in back.  I
unbolted the forward connection on the shock/spring and reached in to adjust
the sequence valve.  The only way that I could hold the valve plunger was
with a hemostat, and I turned the adjustment screw one half turn.  When I
put it all back together the doors still didn't close.  Perhaps the hemostat
allowed the plunger to turn. 

The airplane has 120 hours.  The hydraulic fluid level is OK.  I tried
increasing the pressure with the two adjusting screws and that didn't help.
Al Gietzen, didn't we find that those screws didn't do anything way back
when.... 

Any suggestions? 

Mel Bina 
N14B STD RG

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