Wing Fuel Leak Repair
Fuel leak repairs on the Westwind should be a straightforward issue, but, unfortunately, we have found that to be untrue. Case in point – a Westwind was going through a pre-purchase inspection and 26 #30 holes were found drilled through the upper wing skins at the W.S. 62.0 and 126.0 ribs, both sides. These are the main ribs that form the inner and outer bulkheads of the wheel wells. The holes were put there to inject sealant to fix some leaks, I assume, because some other aircraft were designed to be sealed that way.
I can not find that anywhere as an approved procedure for the Westwind. There wasn’t even a logbook entry. What is so hard about doing these repairs right? We have installed a lot of bushings in wings over the last few years due to misdrilled holes, oversized fasteners, wrong hardware, and just plain negligence.
Watch the fuel crews, ask questions, and if you need to have a repair scheme, contact Worthington Aviation for engineering. They are there to assist you with problem solving. Don’t let sloppy repairs cost you more money down the road.
Friday, April 25, 2003
ATA 27
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.
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.
ATA 72
Acoustic Fatigue May Cause Engine Inlet Cracking
If you are an operator or technician who is dealing with an engine inlet that continuously cracks, consider accomplishing an acoustic survey. Engines with fans that are balanced but have blades that have been blended or cropped may generate noise that can cause acoustic fatigue. If replaced fasteners loosen or cracks continue to appear in the inlet, the engine may be experiencing this condition. Every 200 hours a visual inspection of the engine inlet is required per Chapter 5-20-07 of the Westwind1124/1124A Maintenance Manual. Pay close attention to the inlet aft frames and barrel for cracks, as well as inspecting the entire structure for loose and missing rivets. An acoustic survey could determine if this noise is the cause of the problem and possibly help you avoid costly inlet repairs.
If you are an operator or technician who is dealing with an engine inlet that continuously cracks, consider accomplishing an acoustic survey. Engines with fans that are balanced but have blades that have been blended or cropped may generate noise that can cause acoustic fatigue. If replaced fasteners loosen or cracks continue to appear in the inlet, the engine may be experiencing this condition. Every 200 hours a visual inspection of the engine inlet is required per Chapter 5-20-07 of the Westwind1124/1124A Maintenance Manual. Pay close attention to the inlet aft frames and barrel for cracks, as well as inspecting the entire structure for loose and missing rivets. An acoustic survey could determine if this noise is the cause of the problem and possibly help you avoid costly inlet repairs.
ATA 10/52
Use of Emergency Exit Door Wedge Locks
Operators concerned with protecting their Westwind or Astra may choose to secure the cabin emergencyexit doors using the lock wedges supplied as loose equipment with a new aircraft. The lock wedge is a simplewooden device that is inserted on the lower surface of the inner door release handle with the notch of the wedgepointing downward. When properly installed, the wedge will prevent opening of the exit from outside theaircraft. After inserting the wedge, double-check its security by testing the outside handle to be sure the wedgeis doing its job.
Operators concerned with protecting their Westwind or Astra may choose to secure the cabin emergencyexit doors using the lock wedges supplied as loose equipment with a new aircraft. The lock wedge is a simplewooden device that is inserted on the lower surface of the inner door release handle with the notch of the wedgepointing downward. When properly installed, the wedge will prevent opening of the exit from outside theaircraft. After inserting the wedge, double-check its security by testing the outside handle to be sure the wedgeis doing its job.
ATA 32
Anti-Skid System Transducer Drive Cap Gap
Every maintenance technician knows the important part the wheel speed transducers play in the brake anti-skid system operation. Many of us don't give much thought to the drive cap, but the system manufacturer indicates the gap of the spring drive clip is critical for proper low-speed anti-skid function.The proper gap of the spring drive clip mounted inside the 1124 main wheel dust cap is 0.140 in. +/- 0.010in. Technicians should be sure to check the condition of the clip and its gap at each removal and installation ofthe dust cap. Excessive clip gap may cause the anti-skid system to process false signals from the wheel speed transducers and command full-release of the brakes at speeds between 10-20 knots. The inspection criteria arein the 1124 Maintenance Manual, Chapter 32-44-06.
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