Joel B. Schwartz

The disassembly required on this AD is potentially very destructive. It asks for the drilling of rivets to remove a rib from the elevator. The chance of either the rib or the elevator skin being damaged during this process is very high. No spares exist for either the rib or the skin and this would render the plane un-airworthy -indefinitely!! Prior to the issuance of the AD and after hearing of issues, my A&P and I did a very good inspection of the area with a borescope just to be safe. The area is easily accessible on most years of Commander with a scope. On the few years that a full length rib was used I can see the need to drill the rib rivets but on other years this is excessive and very costly. Please consider the Scope method for initial inspection and disassembly only if suspect areas are noted. This area will have to be disassembled again once a Terminating AD is issued and many skins and ribs will not survive being disassembled multiple times.