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FAA orders · airworthiness directive · historical

99-24-04: Hi-Lok Pin Fasteners

FAA order 99-24-04 is an airworthiness directive in force since December 27, 1999. The FAA's subject line: Hi-Lok Pin Fasteners. It names Douglas DC-9, Mcdonnell Douglas Aircraft Co MD-88, Mcdonnell Douglas DC-9: about 110 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: airframe structure.

What it applies to as the FAA lists it

Kind of product
Aircraft
Makes
McDonnell Douglas Corporation
Models
DC-9-81, DC-9-82, DC-9-83, DC-9-87, MD-88
On this site
Douglas DC-9 7 registered
Mcdonnell Douglas Aircraft Co MD-88 10 registered
Mcdonnell Douglas DC-9 93 registered

Dates and paperwork

In force since
December 27, 1999
Published
November 19, 1999 (signed November 10, 1999)
Docket
99-NM-05-AD
Replaced by
99-24-04 C1
Status
Historical
The FAA's document
Read the order on the FAA's site

The FAA's summary their words, unchanged

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes, that requires a one-time visual inspection to determine whether self-aligning nuts are installed at certain locations of the aft pressure bulkhead tee; and corrective actions, if necessary. This amendment is prompted by reports of failures of certain Hi-Lok pin fasteners of the aft pressure bulkhead tee due to installation of non-self-aligning nuts. The actions specified by this AD are intended to prevent failure of certain Hi-Lok pin fasteners and subsequent gouging of the aft pressure bulkhead tee, which could result in fatigue cracking and reduced structural integrity of the airplane.

The order itself the regulatory text, as published

Show the full text (5,495 characters)
99-24-04 McDonnell Douglas: Amendment 39-11428. Docket 99-NM-05-AD. \n\n\tApplicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 airplanes; as listed in McDonnell Douglas Service Bulletin MD80-53-201, Revision 02, dated July 20, 1998; certificated in any category. \n\n\tNote 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent failure of certain Hi-Lok pin fasteners and subsequent gouging of the aft pressure bulkhead tee, which could result in fatigue cracking and reduced structural integrity of the airplane, accomplish the following: \n\nInspection \n\n\t(a) Within 48 months after the effective date of this AD, perform a one-time general visual inspection to determine whether self-aligning nuts are installed at certain locations of the aft pressure bulkhead tee, in accordance with McDonnell Douglas Service Bulletin MD80-53-201, Revision 02, dated July 20, 1998, as revised by Information Notice MD90-53-201 R02, dated October 21, 1998. \n\n\tNote 2: For the purposes of this AD, a general visual inspection is defined as "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked." \n\n\t(1) If all nuts installed are self-aligning, no further action is required by this AD. \n\n\t(2) If any nut is determined to be non-self-aligning, prior to further flight, remove the existing nut and perform a one-time visual inspection to detect gouges in the aft pressure bulkhead tee on station Y=1338.000 and longeron end fitting, as applicable, in accordance with the service bulletin. \n\n\t(i) If no gouge is detected, prior to further flight, install new self-aligning nuts in accordance with the service bulletin. \n\n\t(ii) If any gouge is detected that is within the repair limits specified in the service bulletin, prior to further flight, repair the gouge and install new self-aligning nuts inaccordance with the service bulletin. \n\n\t(iii) If any gouge is detected that is outside the repair limits specified in the service bulletin, prior to further flight, repair in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\tNote 3: Inspections, and repair of the aft pressure bulkhead tee longeron end fittings prior to the effective date of this AD, in accordance with McDonnell Douglas Service Bulletin MD80-53-201, dated July 6, 1988, or Revision 1, dated March 22, 1991, are considered acceptable for compliance with the actions required by paragraph (a) of this AD. \n\nAlternative Methods of Compliance \n\n\t(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO. \n\n\tNote 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\nSpecial Flight Permits \n\n\t(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\nIncorporation by Reference \n\n\t(d) Except as provided by paragraph (a)(2)(iii) of this AD, the actions shall be done in accordance with McDonnell Douglas Service Bulletin MD80-53-201, Revision 02, dated July 20, 1998. 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 The Boeing Company, Douglas Products Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Dept. C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(e) This amendment becomes effective on December 27, 1999.

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Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 3, 2026. Connections as data: /graph/directive/99-24-04.json · aircraft systems.