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When the rudder is removed for any reason, take a look inside the torque tube (rudder post). there has been found quite a bit of debris accumulated at the bottom. There is no drain for this area, so any water, paint stripper, etc. will remain, possibly leading to corrosion. We have removed several for cleaning, inspection. and corrosion treatment and have had to replace one.

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Rudder Trim
Several new Westwind operators have called us asking why their aircraft “wing walks”. We have heard this same question for years, so we thought we would offer a few suggestions to help correct the problem. First, though, the pilot and mechanic need to understand the difference between wing walk and “Dutch roll”. The first is a roll axis problem and the second is a yaw axis problem—two different controls with very similar characteristics. Almost every Westwind we have worked this problem on has turned out to have a very slight Dutch roll. In almost every case, we were able to either eliminate the problem or lessen it to a greater degree by doing the following:

1. Run the rudder trim to the right stop and hold the trim switch in that position for 2-3 seconds. (DO NOT depend on the trim indicator for any of this.)
2. Run the trim to the left stop and again hold the switch.
3. Center the trim and go fly.

The trim actuators are not connected and will run at slightly different speeds. Over a period of time, they will position themselves out of rig and will bend the tab out of shape—causing a Dutch roll. Synchronizing the actuators again will straighten the tab. Don’t worry, it doesn’t hurt the tab at all.

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Rudder Airworthiness Directive (AD) 2004-14-14
We have received confirmation from the FAA that aircraft that have previously been inspected inaccordance with Section 5-40-03 (dated January 31, 2003) of the structural inspection program (structural“B”) meet the requirements of paragraph (a).We are discussing an adjustment to the AD compliance time of 50 hours with the FAA. It seems that theFAA, Civil Aviation Administration of Israel (CAAI), and Israel Aircraft Industries (IAI) weren’t in agreementas far as the compliance times were concerned. Unfortunately, your local Flight Standards District Office(FSDO) is not authorized to grant an extension to the 50-hour limit. That must be done through the FAA inSeattle using the Alternate Means of Compliance (AMOC) procedure. Contact Dan Rodina at 425-227-2125.He is the FAA person whose name is at the bottom of the AD.

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Westwind Service Bulletin 1124-55-150 Rudder Inspection
We recommend that the rudder be removed from the aircraft for this inspection due to the number of x-rayshots required and the height from the floor that the camera must be lifted—it could make a big dent in stabs and elevators!
If crack indications are found on your rudder, find out from the NDT tech which side they are on. If he’s good, he can tell you. If he says right, you may be in luck. It seems that the factory assembled rudders with narrow ribs and installed a whole bunch of 0.025 shims on the right-hand rib flanges to make the skin come outeven. Where the shims intersected stiffeners, flanges, etc., the hole was dimpled. It now shows up as a crack inthe rib. We found this exact problem and replaced the stiffener/shim and saved the customer the cost of an exchange rudder.
Bear in mind that there can still be cracks in left rib flanges and skins, but find out for sure before making your decision.