KLM Fleet Services

General: During the first accomplishment of scribe mark inspections on a KLM 747, KLM encountered numerous difficulties with the inspection methods described in the Service Bulletin. KLM discussed these difficulties with Boeing Service Engineering in finding solutions. KLM found the following major basic difficulties when performing the Service Bulletin (SB) inspections: 1) Interpretation of the required inspection areas and details are vague and ambiguous and are open for misinterpretations. 2) Some of the NDT inspections could not be performed as per the published procedure/s without modification of the process itself. 3) The SB provides for some relief for un-inspectable locations. However, this relief is insufficient for several structural details, and no alternative inspection method is available. 4) The interpretation of the repeat inspection compliance tables is vague and ambiguous and open for misinterpretations. Although KLM realizes that these comments do not specifically concern the content of the NPRM, the issues discussed above, when unresolved, will strongly affect the compliance and accomplishment of the AD/SB inspections as detailed in the NPRM. KLM therefore would like the FAA to coordinate with Boeing and resolve these issues prior to issuance of the AD. This would also eliminate AMOC requests pertaining to the above. KLM would like to inform the FAA that the first accomplishment of the Service Bulletin is currently still in progress.