AD 84-10-05

84-10-05 MESSERSCHMITT-BOLKOW-BLOHM-GmbH: Amendment 39-4864. Applies to HFB-320 airplanes as listed in HFB-320 Service Bulletin 57-19 dated February 5, 1982, certificated in all categories. Compliance is required within the next 150 hours time in service or 90 days, whichever occurs first after the effective date of this AD for airplanes with 2400 hours total time in service on the effective date. All others must comply before accumulating 2550 hours time in service, but no later than 90 days after accumulating 2400 hours. To prevent failure of the upper surface wing structure accomplish the following, unless previously accomplished:

A. Perform a one-time inspection of the wing upper skin in accordance with the service bulletin. Repair cracks per the manufacturer's instructions.

B. Alternate 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.C. Special 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.

This amendment becomes effective May 29, 1984.