Here is a tip for determining ply count. If you’re looking at a solid laminate and don’t know the ply count, you can measure the thickness to determine it. The thickness of one ply is generally between 0.008 and 0.010 inch. So, if you measure the total thickness of the laminate and divide by 0.009, you can determine the ply count.
Cirrus has established a wet lay-up composite repair process. No vacuum system is necessary. Volinkaty says that the repair procedure was chosen so that shops were not forced to buy expensive curing equipment. Instead, the mechanic fabricates a tent to create an envelope around the repair area. A dryer is used with a thermostat to control the cure cycle of the repair.
Cirrus wanted mechanics in the field to be knowledgeable about proper repair procedures when working on Cirrus aircraft. The company has created several training opportunities that can help increase a mechanic’s proficiency when it comes to inspecting and maintaining Cirrus aircraft.
Cirrus has developed an online training program called the SR Series AvMx course. It covers inspecting, repairing, troubleshooting, and maintaining Cirrus SR-series airplanes. The course features seven interactive lessons, each with several multi-step challenges, that simulate aircraft maintenance in real-world situations such as busy schedules, difficult customers, and unpredictable situations. This course is a prerequisite for anyone wishing to attend other Cirrus training.
“Our online program has several benefits,” says Doug Larson, Cirrus senior technical instructor. “First of all, while the first section of the course deals with technical publications, they are referenced throughout all seven lessons. The mechanic becomes proficient with using the manuals. Second, it allows us to do a lot of the initial training before a mechanic steps foot in the Duluth classroom.” As Larson shares, mechanics have a widely varying amount of knowledge and experience when it comes to composites. By covering the basics in an online course, everyone starts off on a level playing field when they step foot in the Duluth classroom.
Cirrus provides a one-week composite repair laboratory in composite inspection and repair. If you enjoy sitting in a classroom for hours on end, this course is not for you. After a few hours of review and a safety briefing, you are in the lab with your respirator, safety glasses, and Tyvek suit performing composite repairs. The composite repair lab has a large resource of composite pieces on hand to work on. That way, the student gets the opportunity to get his or her feet wet by working on the actual structure he would see in the field before doing it on an actual aircraft.
I had the opportunity to take both the online course and the composite repair laboratory. Having never worked on a Cirrus before, I came away with information that I could apply to repair or inspection situations in the field. These courses are a valuable resource for any mechanic who will be maintaining or inspecting Cirrus aircraft.
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