AD 98-13-35 R1

On June 17, 1998, the FAA issued AD 98-13-35, amendment 39-10626 (63 FR 34585, June 25, 1998), which is applicable to certain McDonnell Douglas Model DC-9 and DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes. That AD requires repetitive high frequency eddy current inspections of certain areas of the fuselage to detect cracks of the skin and/or longeron, and various follow-on actions. That AD also requires installation of a preventative modification, which terminates the repetitive inspections. That action was prompted by reports indicating that, due to material fatigue caused by installation preload and cabin pressurization cycles, fatigue cracks were found in the skin and longerons of the fuselage. The actions required by that AD are intended to prevent such fatigue cracks, which could result in loss of the structural integrity of the fuselage and, consequently, lead to rapid depressurization of the airplane.

Actions Since Issuance of Previous Rule

Since the issuance of AD 98-13-35, the FAA has received information from the manufacturer that the specified area of the initial inspection requirements of paragraph (a) of that AD differs from the service information provided in McDonnell Douglas DC-9 Service Bulletin 53-235, dated September 15, 1993 (cited in the AD as the appropriate source of service information for accomplishment of the required actions).

The FAA's intent in AD 98-13-35 was to require the actions described in McDonnell Douglas DC-9 Service Bulletin 53-235. In order to prevent operators from misinterpreting the specific area of the initial inspection, the FAA finds that the inspection requirements of paragraph (a) must be revised to specify inspection only of the fuselage, in lieu of the fuselage skin and/or longeron. Accordingly, this action revises paragraph (a) of the existing AD to remove reference to inspection of the longeron and to limit the area that is subjectto the inspection (skin between stations Y=160.000 and Y=218.000; skin at the longeron attachments).

Action is taken herein to clarify and correct these requirements of AD 98-13-35 and to correctly add the AD as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13).

The final rule is being reprinted in its entirety for the convenience of affected operators. The effective date remains July 30, 1998.

Since this action only clarifies and corrects a current requirement, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Correction

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39 - AIRWORTHINESS DIRECTIVES

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

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 (Amended)

2. Section 39.13 is amended by removing amendment 39-10626 (63 FR 34585, June 25, 1998), and by adding a new airworthiness directive (AD), amendment 39-11086, to read as follows: