91-21-08 BRITISH AEROSPACE: Amendment 39-8055. Docket No. 91-NM-50-AD. Supersedes AD 90-08-18.
Applicability: Model BAC 1-11 200 and 400 series airplanes on which Modification PM1573 has been incorporated, certificated in any category.
Compliance: Required as indicated, unless previously accomplished.
To prevent reduced structural integrity of the tailplane, accomplish the following:
A. Perform the following specified initial inspections to detect corrosion and cracks in the tailplane lower skin panel and stringers:
1. Perform an external visual inspection, in accordance with British Aerospace Alert Service Bulletin 55-A-PM5827, Issue 2, dated September 5, 1990, prior to the latest of the following compliance times:
a. Within 90 days after the effective date of this AD; or
b. Within one year after the most recent external visual inspection to detect corrosion and cracks in the tailplane lower skin panel and stringer that was accomplished in accordance with AD 90-08-18, Amendment 39-6578 (British Aerospace Alert Service Bulletin 55-A-PM5827, Issue 1, dated July 24, 1981); or
c. Within ten years of the date of manufacture of the airplane.
2. Perform a detailed internal visual inspection, in accordance with British Aerospace Alert Service Bulletin 55-A-PM5827, Issue 2, dated September 5, 1990, prior to the latest of the following compliance times:
a. Within 270 days after the effective date of this AD; or
b. Within 3 years after the most recent internal visual inspection to detect corrosion and cracks in the tailplane lower skin panel and stringer that was accomplished in accordance with AD 90-08-18, Amendment 39-6578 (British Aerospace Alert Service Bulletin 55-A-PM5827, Issue 1, dated July 24, 1981); or
c. Within ten years of the date of manufacture of the airplane.
B. Repeat the inspections required by paragraph A. of this AD, at the following intervals:1. External visual inspections must be repeated at intervals not to exceed one year.
2. Internal visual inspections must be repeated at intervals not to exceed three years.
NOTE: These inspections can be combined, as long as the repetitive interval indicated for each type is not exceeded.
C. If corrosion is found as a result of the visual inspection required by paragraph A. or B. of this AD, prior to further flight, accomplish the following, in accordance with the Accomplishment Instructions in British Aerospace Alert Service Bulletin 55-A-PM5827, Issue 2, dated September 5, 1990.
1. If corrosion found is within the limits specified in the Structural Repair Manual, Chapter 55-01-0, Table 1, repair the affected area and restore the protective treatment, in accordance with paragraph 2.2.1 of the service bulletin.
2. If corrosion found is outside the limits specified in the Structural Repair Manual, Chapter 55-01-0, Table 1, but has not completelypenetrated the skin, repair in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.
3. If corrosion found is outside the limits specified in the Structural Repair Manual, Chapter 55-01-0, Table 1, and one or more areas have completely penetrated the skin, perform an internal visual inspection of the tailplane bottom skin and stringers to establish the extent and depth of corrosion, and repair in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.
D. If cracks are found, prior to further flight, repair in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.
E. 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.
F. 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.
G. The inspection and repair requirements shall be done in accordance with British Aerospace Alert Service Bulletin 55-A-PM5827, Issue 2, dated September 5, 1990. 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, 1601 Lind Avenue S.W., Renton, Washington; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.Airworthiness Directive 91-21-08 supersedes AD 90-08-18, Amendment 39-6578.
This amendment (39-8055, AD 91-21-08) becomes effective on November 19, 1991.