AD 90-03-06

90-03-06 BRITISH AEROSPACE (BAe), PLC: Amendment 39-6476. Docket No. 89-NM-157-AD.

Applicability: Model BAe/BH/DH/HS 125-1A, -3A, -400A, and -600A series airplanes, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To ensure continued structural integrity, accomplish the following:

A. Perform a visual and X-ray inspection for corrosion and/or cracking of the keel skin and local structures between frame 7 and frame 13 and stringers 15 left and 15 right, and center line keel skin lap joint and hydraulic duct attachment angles (left and right) between the nose wheel bay and frame 7, in accordance with British Aerospace Service Bulletin 51-4, dated May 31, 1989, as follows:

1. Initial inspection:

a. For airplanes on which visual inspections and X-ray inspections, detailed in the Airplane Maintenance Schedules and Non-destructive Testing Techniques, have been accomplished within the last two years prior to the effective date of this AD, and where no significant defects were found, perform this inspection within one year after the effective date of this AD.

b. For all other airplanes, perform the initial inspection within 180 days after the effective date of this AD.

2. Repetitive Inspection:

a. Following the initial inspection required by paragraph A.1. of this AD, perform repetitive inspections at intervals not to exceed 4 years in accordance with Service Bulletin 51-4, or

b. Within one year of the initial inspection required by paragraph A.1. of this AD, revise the FAA-approved maintenance program to include all inspection procedures described in Service Bulletin 51-4, and repeat the inspection at intervals not to exceed 4 years.

B. In areas where corrosion or cracking is found or suspected, prior to further flight, strip off paint and perform a dye penetrant inspection.

C. Any cracks and/or corrosion found which are within the limits specified inthe Structural Repair Manual, must be repaired prior to further flight, in accordance with Service Bulletin 51-4, dated May 31, 1989. Repetitive inspections must be performed thereafter at intervals specified in paragraph A., above.

D. Any cracks and/or corrosion found which exceed the limit of the Structural Repair Manual, must be repaired prior to further flight, in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region. Repetitive inspections must be performed thereafter at intervals specified in paragraph A., above.

E. 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.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either 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.

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, PLC, Librarian for Service Bulletins, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Standardization Branch, 9010 East Marginal Way South, Seattle, Washington.

This amendment (39-6476, AD 90-03-06) becomes effective on February 20, 1990.