91-14-18 BRITISH AEROSPACE: Amendment 39-7059. Docket No. 91-NM-42-AD.
Applicability: All Viscount Model 744, 745D, and 810 series airplanes, certificated in any category.
Compliance: Required as indicated, unless previously accomplished.
To prevent reduced structural integrity of the wings, accomplish the following:
A. Within 180 days after the effective date of this AD, and thereafter at intervals not to exceed 180 days, perform an eddy current inspection to detect corrosion along the total length of the top surface of the left and right wing spar upper boom in accordance with British Aerospace Preliminary Technical Leaflet (PTL) No. 321, Issue 1, dated January 13, 1989, or PTL No. 190, Issue 1, dated January 13, 1989, as applicable.
B. If corrosion is found, prior to further flight, repair in accordance with PTL No. 321, Issue 1, dated January 13, 1989, or PTL No. 190, Issue 1, dated January 13, 1989, as appropriate; or in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.
C. An alternative method 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, Transport Airplane Directorate.
NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.
D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.
E. The inspections and repair requirements shall be done in accordance with British Aerospace Preliminary Technical Leaflet (PTL) No. 321, Issue 1, dated January 13, 1989, or PTL No. 190, Issue 1, dated January 13, 1989, as applicable. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from British Aerospace, PLC, Librarian for Service Bulletins, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041-0414. Copies may be inspected at the FAA, Transport Airplane Directorate, Renton, Washington; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.
This amendment (39-7059, AD 91-14-18) becomes effective on August 6, 1991.