William Paul Hopkins

Dear Sir or Madam, I am the owner of Rockwell Commander 112 serial number 410 and a member of the Commander Owners Group (COG). I have deep concern as to the inspection procedure proscribed in the subject AD to detect cracks in the elevator spar for this type certificate. They are: * The procedure requires the removal of multiple rivets to disassemble the elevator for inspection. There are very limited or no replacement parts available (elevator skin, outboard end rib, elevator spar) should any be damaged during removal or re-installation. * All cracks found to date were visible using the CPAC/Aerodyme visual inspection methods published on the COG website. All CPAC, COG and Aerodyme engineering personnel agree that, given the thinness of the elevator spar material, any spar crack hidden by the elevator hinge would be clearly visible on the aft side of the spar using the aforementioned visual inspection method. * The estimated cost of the inspection as per the AD is not realistic and is expected to take up to twice as much time to complete according to COG members who are engineers, APs and IAs. * There is no terminating action proscribed as yet for this AD. The destructive nature of the inspection process make a recurring inspection IAW the AD extremely risky. I take very seriously the news that cracks have been found on seven (7) Commander aircraft and agree that swift inspection of the fleet is required. However, for the reasons I've listed above, I urge you to approve the visual inspection procedure developed by CPAC and Aerodyme as sufficient to satisfy inspection requirements of the AD. For the record, Aerodyme did a thorough visible inspection of my elevator spars as part of their "Superstream" STC work and found no cracks. Please feel free to contact me with any questions or concerns you may have. Thank you for your consideration. Sincerely yours, William P. Hopkiins