REFLECTOR: Front Vibration

[Andy Millin]

Rene,

Just a guess, but if it were a possible loose connection with an elevator
hinge, shouldn't you be able to get the vibration to stop, or at least
change, momentarily with a firm pitch up?

Some things I might try.  Get the vibration started.  Pull the engine and
prop back to idle.  Put it nose down to maintain the same airspeed.  If the
vibration stops then it is probably engine related and not airframe.  If it
doesn't, then vice-versa...

I'm building an FG so I don't know that much about the limits with the RG.
This problem happens at high speed, so I doubt you can try it with the gear
extended.  Would be nice to try that speed with the gear down.  Could tell
you if it was related to any part of the RG system.

At that speed and by your description, it could be related to any gap or
opening in the fuselage.  You feel it is in the nose so I would start at the
landing light and work backwards.  Try to change something about each item
that would make the problem standout.  Like take the lens off of the landing
light and go flying.  Try taping the nose access cover seam, and go flying.
Check the canard doghouse (tape them and fly).  Check the elevator torque
tube through the fuselage hole.

I don't know if you can take the doors off the RG system and go flying or
not.  It would be breezy, but it might tell you if the problem is with the
doors.

Is there any way you could get a passenger to go with you and reach under
and feel the torque tubes while it is happening.  Might be feedback and you
could tell which elevator...

Just trying to find what is causing it first.  Then fix it.

Best regards,

Andy


-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Rene Dugas
Sent: Thursday, September 30, 2004 1:46 PM
To: reflector at tvbf.org
Subject: REFLECTOR: Front Vibration


Thanks fellows for the input.
I may try, as stated, to change my incidence SLIGHTLY.  The Gear doors are
Very tight.  I can only pry them open with a screw driver.  I also found the
slightest slack in the last pilot side elevator hinge bushing.  I will try
to replace.  At high wind velocity it could cause a slight motion.  
Rene'