Astra / Westwind Spring 2005

• Astra Aileron Bearings
• Universal Avionics Service
• Westwind/Astra Oxygen Regulators

Astra Aileron Bearings

- Tim Garity

As the aircraft ages, some flight control bearings become dry and rough affecting flight control operation. This article addresses the aileron hinge bearings, as they are the most difficult to deal with. First, a little history. Aircraft pre-SB 1125-27-116 have aileron bearings that require lubrication and the removal of the ailerons at every C check. Aircraft that have this SB incorporated have permanently lubed bearings. If the ailerons are removed for this SB, it presents an opportunity to comply with SB 1125-27-228, which adds a mod to make the bearings rotate, instead of the bushings. The difficulty I mentioned is the fact that special tooling is required to remove and install aileron bearings. The bearing assembly is comprised of the actual bearing and a retainer that must be swaged in place to capture the bearing. The tooling is in very short supply and is difficult to use. For this reason, we have made our tooling and technicians available to come to your location for bearing issues. To schedule a Duncan Aviation technician, contact Tim Garity at 800.228.4277.

Universal Avionics Service

- Don Fiedler

Duncan Aviation-LNK has been selected as the first and only authorized service center in the United States for Universal Avionics. Duncan Avionics has acquired Universal’s test equipment and will be authorized to perform unit repairs at the board level, including board exchanges, modifications, software updates and battery replacements for both warranty and non-warranty units.

Duncan Aviation technicians have completed all training requirements and all certificates and manuals relevant to this service center agreement are now housed in Lincoln. Duncan Aviation’s satellite network will be authorized to perform inaircraft troubleshooting as well as to remove and replace Universal equipment.

For more information about this service center agreement, please call 800.LOANERS and speak to any of our avionics technical representatives.

Westwind / Astra Oxygen Regulators

- Tim Garity

We recently experienced a problem with a Westwind regulator that we would like to share. We found an out-of-limits internal leak while performing the leakage test required by the Westwind C Check inspection guide.We ordered an exchange regulator. There is no requirement to test the newly overhauled part for leakage, but at the operator’s request, we did test it and it failed. To make a long story short, we ordered and failed 3 additional overhauled regulators. Having access to the Component Maintenance Manual (CMM), we were able to open one of the overhauled regulators. We found the inlet fitting (inside the box ) was leaking. It is a simple pipe thread connection, but it was being sealed with a jam-nut, with a teflon-type seal. Having never seen a jam-nut on pipe threads before, we disassembled the fitting for a closer look. The jam nut threads were stripped, so it wasn’t tight against the fitting.We also noted that the jam-nuts are not shown in the CMM.We sealed the fitting with teflon tape and were able to stop the leakage. From this we learned there is a shortage of spare regulators, there is only one company that works on them, and we will leak check all replacement regulators. The P/N of these units is 112031-06, and it is also used in some Astra aircraft (serial numbers 004-099, according to the IPC), although the Astra Maintenance Manual does not require the leakage test like the Westwind.

If you have technical questions about your Astra or Westwind aircraft, contact Tim Garity at 800.228.4277.

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