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99-21-10: Skin Panels of Lower Fuselage

FAA order 99-21-10 is an airworthiness directive in force since November 12, 1999. The FAA's subject line: Skin Panels of Lower Fuselage. It names Boeing 727: about 37 aircraft on the U.S. register today, 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
The Boeing Company
Models
727-100 Series, 727-100C Series
On this site
Boeing 727 37 registered

Dates and paperwork

In force since
November 12, 1999
Published
October 7, 1999
Docket
98-NM-367-AD
Status
Current
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 Boeing Model 727-100 and -100C series airplanes, that requires replacement of certain skin panels of the lower fuselage with non-bonded skin panels. This amendment is prompted by reports of corrosion of the skin panels of the lower fuselage on airplanes with hot-bonded doublers. The actions specified by this AD are intended to prevent degradation of the structural integrity of certain skin panels of the lower fuselage, which could result in loss of airplane pressurization.

The order itself the regulatory text, as published

Show the full text (3,964 characters)
99-21-10 BOEING: Amendment 39-11353. Docket 98-NM-367-AD. \n\n\tApplicability: Model 727-100 and -100C series airplanes; line numbers 126, 130, 146, 153, 221, 287, 331, 339, 345, 355, 416, 516, 532, 540, 551, 555, 559, 575, 592, 594, 596, 599, 600, 604, 605, 615, 619, 625, 626, 628, 630, 631, 632, 635, 640, 641, 643, 645, 647, 658, 660, 686, 695, 700, 711, 712, 735, 748, 766, 768, 784, 797, 803, 806, 810, 812, 817, 821, 822, 824, 829, 854, 856, 857, 858, 861, and 869; 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 shouldinclude 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 degradation of the structural integrity of certain skin panels of the lower fuselage, which could result in loss of airplane pressurization, accomplish the following: \n\n\t(a)\tWithin 20 years since original installation, or within 4 years after the effective date of this AD, whichever occurs later, replace the skin panels of the lower fuselage between body station (BS) 950 and BS 1183 with non-bonded skin panels, in accordance with Part VI of the Accomplishment Instructions of Boeing Service Bulletin 727-53-0085, Revision 4, dated July 11, 1991. \n\n\tNOTE 2: Accomplishment of the modification specified in Boeing Service Bulletin 727-53-0085, Revision 2, dated July 3, 1975, or Revision 3, dated September 28, 1989, is acceptable for compliance with the replacement required by paragraph (a) of this AD. \n\n\tNOTE 3: Accomplishment of the modification specified in paragraph (a) of this AD constitutes terminating action for the inspection requirements of AD 92-19-10, amendment 39-8368 (57 FR 47404, October 16, 1992) for those panels. \n\nAlternative Methods of Compliance \n\n\t(b)\tAn 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, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle 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 Seattle ACO. \n\nSpecial Flight Permits \n\n\t(c)\tSpecial 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)\tThe replacement shall be done in accordance with Boeing Service Bulletin 727-53-0085, Revision 4, dated July 11, 1991. 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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(e)\tThis amendment becomes effective on November 12, 1999.

Related safety bulletins advice on the same designs, not orders

2014-11-24NM-15-03 · Flight Controls
2014-11-06NM-15-02 · Cabin Equipment/Furnishings
2010-01-07NM-10-13 · Navigation: Flight Management System
2006-07-19NM-06-56 ·
2002-03-13NE-02-18 · Air Cruisers Company Evacuation Slide and Slide/Raft Systems

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/99-21-10.json · aircraft systems.