Airframe Technology: Scratches and Dings

After customers photograph and document the damage or wear, they call West Star technical services staff that consults and walks customers through the evaluation. The strength of this do-it-yourself evaluation is that it has proven to be 100 percent accurate in helping the customer make an informed repair or replace decision. This service can also save a visit from a technician and thousands of dollars in travel and other service fees. West Star strongly recommends this service to customers considering an aircraft purchase. If you buy a preowned aircraft and later find out that a window is bad, the replacement cost can be $2,000-$300,000 depending on the aircraft type and window. 

The contact for West Star Aviation aircraft window repair and refinishing service at Grand Junction is program team leader, Jack Brown.  Brown explains that this “concept came from years of experience and collaboration with team member Chris Becker. When they joined West Star and developed their in-house window repair program, they wanted to do two things. First and foremost was to get customers involved in the window damage evaluation and repair process. They felt this would result in a better informed customer and would lead to more trust, better decisions, savings for the customer, and repeat business. The second reason was to be recognized as a professional, trustworthy service provider. Reputations are very important in this economy and in the competitive aviation service business. 

Repair processes

I asked the West Star staff to discuss the repair processes and offer some maintenance tips to AMTs. They replied that “window repair can be a slippery slope for inexperienced AMTs. Many A&P schools briefly train students to use a simple kit to fix window scratches, pits, and crazing. The determining factor of any window repair is window thickness and damage depth. An improper repair can quickly exceed OEM limits and in some cases, destroy the window. Window repair has been called an art and the experience of the repairman determines the quality of the repair. We have been perfecting our repair processes for years and our goal is to repair, rather than replace an expensive window. It is always cost effective to repair when possible and we always try and find a way to make a distortion free repair that is within OEM limits.”

Some new improvements in window construction should help reduce repairs and extend window service life. Some OEMs are installing thicker windows and adding bushings in the attaching bolt holes. These two improvements should reduce cracks around the bolt hole and allow more repairs. Per West Star, “On some of these thicker windows, we have been able to make up to 10 repairs.”

Sample care tips

AMTs and service personnel must always use the proper designated cleaning cloths. “Too many people will use any old rag and scratch the windows. The scratches lead to heavier crazing and more costly repairs or replacements. We recommend VIVA KLEENEX white paper towels, full sheet, without prints. Flush the windows with loads of water. Absorb water and clean the surface with VIVA, and use Permatex 403 D cleaner for the heavier bug residue. Always turn towels so that on each wipe you have a clean surface to the window. With appropriate service and maintenance, operators should expect windows on their corporate jets to last around 15 years.” 

Brown had these parting words for AMTs that are about to clean or work around a window.  “Please remember that a window is strong enough to take a FOD or bird or hail strike and not break, but it can be easily scratched by a dirty rag.”

Charles Chandler is an A&P based in Texas. He received his training from the Spartan College of Aeronautics.