AD 87-26-06

87-26-06 BRITISH AEROSPACE (BAe): Amendment 39-5806. Applies to all Model H.S. 748 series airplanes, pre-modification 7205, certificated in any category. Compliance required as indicated, unless previously accomplished.

To prevent structural damage to the airplane due to fatigue cracking of the hydraulic accumulators, accomplish the following:

A. Within 300 hours time-in-service after the effective date of this AD, conduct the inspections of the hydraulic brake accumulator, as specified in Paragraph 2.B(1) of BAe H.S. 748 Service Bulletin 29/42, dated February 10, 1986. Any discrepancies detected must be corrected prior to further flight.

B. Within 1,000 hours time-in-service or one year after the effective date of this AD, whichever occurs first, and thereafter at intervals not to exceed 1,000 hours time-in-service or one year, whichever occurs first, conduct the inspections of the hydraulic brake accumulator, as specified in Paragraph 2.B(2) of BAe H.S. 748 Service Bulletin 29/42 dated February 10, 1986. Any system defects found must be corrected prior to further flight.

C. Within 2,500 hours time-in-service, or two years after the effective date of this AD, whichever comes first, and thereafter at intervals not to exceed 2,500 hours time-in-service or two years, whichever occurs first, conduct the inspections of the hydraulic accumulator as specified in Dunlop Service Bulletin 29/175, dated February 4, 1986. Replace, prior to further flight, any units that do not meet the limits specified in the service bulletin.

D. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region.

E. 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.All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to British Aerospace Group, Weybridge Division Greengate, Middleton, Manchester M24 1SA, England; and Dunlop Limited, Aviation Division, Dunlop House, Ryder Street, St. James's, London SW1Y.6PX, England. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way, Seattle, Washington.

This amendment becomes effective February 1, 1988.