Steve Baidwan

Dear Sir/Madam, To my previous comments on AD 90-25-05 please note that AD 90-06-06 which is just as complex and requires number of SB accomplishment does not remark to integrate the AD in to FAA Aprpoved Maintenance Program and also relies on Boeing D6 document as governing standard. Both AD refer to Boeing D6 document however technically AD 90-25-05 applies only to Operators with FAA Approved Maintenance Programs, which basically excludes majority of Operators and leaves them an option to paritally comply or not at all. If CPCP program is designed to prevent structural failures from corrosion and early detection of problematic areas, reporting Level 2 and 3 corrosion findings for data accumulation for Boeing and also to inspect and treat corrosions of any level and protect areas with CIC applications, then this AD should be revised to include world wide operators. Regards Steve Baidwan Global Aviation 90-06-06 BOEING: Amendment 39-6490. Docket No. 89-NM-68-AD. Applicability: Model 747 series airplanes, listed in Boeing Document No. D6- 35999, dated March 31, 1989, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent structural failure, accomplish the following: A. Prior to reaching the incorporation thresholds listed in Boeing Document No. D6- 35999, dated March 31, 1989 (hereinafter called "the Document"), or within the next 4 years after the effective date of this AD, whichever occurs later, except as noted in paragraph B., below, accomplish the structural modifications listed in Section 3 of the Document.