RULES and REGULATIONS

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 88-NM-100-AD; Amdt. 39-6267]

Airworthiness Directives; Boeing Model 747 Series Airplanes

Tuesday, July 18, 1989

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 

series airplanes, that requires ultrasonic and visual inspections for cracks and corrosion, and overhaul, if necessary, 

of the wing landing gear beam outboard end fittings. This amendment is prompted by reports of a fracture of a left 

wing landing gear beam outboard end fitting on one airplane. This condition, if not corrected, could result in separation of the outboard end of the landing gear beam with possible damage to adjacent control cables or hydraulic lines 

in the area of the landing gear beam.

EFFECTIVE DATE: August 22, 1989.

ADDRESSES: The applicable service information may be obtained from Boeing Commercial Airplanes, P.O. Box 

3707, Seattle, Washington 98124. This information may be examined at the FAA, Transport Airplane Directorate 

Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification 

Office, FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington.

FOR FURTHER INFORMATION CONTACT:Mr. Dan R. Bui, Airframe Branch, ANM-120S; telephone (206) 

431-1919. Mailing address: FAA, Northwest Mountain Region, 17900 Pacific Highway South, C-68966, Seattle, 

Washington 98168.

SUPPLEMENTARY INFORMATION: A proposal to amend Part 39 of the Federal Aviation Regulations to include 

an airworthiness directive which requires inspection and overhaul, if necessary, of the wing landing gear beam outboard end fittings on certain Boeing Model 747 series airplanes, was published as a Supplemental Notice of Proposed Rulemaking (NPRM) in the Federal Register on March 17, 1989 (54 FR 11228). The comment period for the 

proposal closed on April 12, 1989.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

The Air Transport Association (ATA) of America, on behalf of its members, expressed no objections to the proposed rule.

The manufacturer recommended that if corrosion is found, the ultrasonic inspections required by paragraph A.

should be repeated at intervals not to exceed 6 months, and rework, in accordance with Boeing Service Bulletin 747-

57-2244, Revision 1, dated July 28, 1988, should be accomplished within 12 months. The FAA has considered the 

manufacturer's recommendation and has determined that if no cracks are detected, the rework for corrosion may be 

delayed up to 12 months, provided the inspection for cracks is accomplished at intervals not to exceed 6 months. 

This procedure will provide an acceptable level of safety, and also provide adequate time for the operators to schedule the rework. A new paragraph has been added to reflect this change.
After careful review of the available data, including the comments noted above, the FAA has determined that air 

safety and the public interest require the adoption of the following rule with the change previously described. The 

FAA has determined that this change will neither increase the economic burden on any operator, nor will it increase 

the scope of the AD.

There are approximately 628 Model 747 series airplanes of the affected design in the worldwide fleet. It is estimated 

that 192 airplanes of U.S. registry will be affected by this AD, that it will take approximately 10 manhours per airplane to accomplish the required actions, and that the average labor cost will be $40 per manhour. Based on these 

figures, the total cost impact of the AD on U.S. operators is estimated to be $76,800.

The regulations adopted herein will not have substantial direct effects on the states, on the relationship between the 

national government and the states, or on the distribution of power and responsibilities among the various levels of 

government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have 

sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a “major rule” under Executive Order 12291; (2) 

is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) 

will not have a significant economic impact, positive or negative, on a substantial number of small entities, under the 

criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and is contained in the 

regulatory docket. A copy of it may be obtained from the Rules Docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration 

amends Part 39 of the Federal Aviation Regulations as follows:

PART 39—[AMENDED]

1. The authority citation for Part 39 continues to read as follows:

Authority: 49 U.S.C. 1354(a), 1421, and 1423; 49 U.S.C. 106(g) (Revised Pub. L.

97-449, January 12, 1983); and 14 CFR 11.89.

§ 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Boeing: Applies to Model 747 series airplanes, listed in Boeing Service Bulletin 747-57-2244, Revision 1, dated 

July 28, 1988, certificated in any category. Compliance required as indicated, unless previously accomplished.

To prevent failure of a wing landing gear beam outboard end fitting with possible damage to control cables or hydraulic lines in the area of the landing gear beam, accomplish the following:

A. Prior to the accumulation of 30,000 flight hours, or 8 years in service, whichever occurs first, or within the next 

14 months after the effective date of this AD, whichever occurs later, visually inspect around the fitting lug bushings 

at the wing landing gear beam outboard end fittings for corrosion, and ultrasonically inspect the wing landing gear 
beam outboard end fittings for cracks, in accordance with Boeing Service Bulletin 747-57-2244, Revision 1, dated 

July 28, 1988.

B. If no cracking or corrosion is found, repeat the inspections required by paragraph A., above, at intervals not to 

exceed 18 months.

C. If cracking is found, prior to further flight, remove the wing landing gear beam outboard fitting, and rework in 

accordance with Boeing Service Bulletin 747-57-2244, Revision 1, dated July 28, 1988.

D. If only corrosion is found, rework in accordance with Boeing Service Bulletin 747-57-2244, Revision 1, dated 

July 28, 1988, within the next 12 months. The ultrasonic inspections for cracks required by paragraph A., above, 

must be accomplished at intervals not to exceed 6 months until rework is accomplished.

E. Terminating action for the inspections required by paragraphs A. and B., above, consists of rework of the wing 

landing gear beam outboard fittings in accordance with Boeing Service Bulletin 747-57-2244, Revision 1, dated July 

28, 1988.

F. 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, Seattle Transport Airplane Office, FAA, Northwest Mountain 

Region.

Note: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any

comments and then send it to the Manager, Seattle Transport Airplane Office.

G. 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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 

98124. These documents may be examined at the FAA, Transport Airplane Directorate, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, FAA, Northwest 

Mountain Region, 9010 East Marginal Way South, Seattle, Washington.

This amendment becomes effective August 22, 1989.

Issued in Seattle, Washington, on July 7, 1989.

Leroy A. Keith,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 89-16739 Filed 7-17-89; 8:45 am]

BILLING CODE 4910-13-M

54 FR 30009-01, 1989