83-07-24 BOEING: Amendment 39-4630. Applies to Boeing Model 767 Airplanes VA006- VA012, VA302-VA306, VA501-VA503, VA701-VA702, VA801-VA802, and VA805. To prevent degradation of cargo compartment fire protection system effectiveness, accomplish the following, unless already accomplished.\n \n\tA.\tWithin 30 days after the effective date of this AD, inspect all forward and aft cargo compartment drain valves and rework, if necessary, in accordance with Boeing Service Bulletin 767-51-1 dated January 14, 1983, or later FAA approved revision. \n\n\tB.\tAircraft may be operated after the 30 day compliance period if the inspection has not been completed, provided no cargo is carried in the affected cargo compartments. \n\n\tC.\tAlternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tD.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. \n\n\tAll persons affected by this directive who have not already received the above specified Service Bulletin from the manufacturer may obtain copies upon request to The Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124, or it may also be examined at FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis amendment becomes effective April 25, 1983.