# AD 90-23-14: Fuselage Lap Joints - Type: Airworthiness directive - Status: Historical - Products: Boeing 747-100 Series, 747-100B Series, 747-100B SUD Series, 747-200B Series, 747-200C Series, 747-200F Series, 747-300 Series, 747-400 Series, 747-400D Series, 747-400F Series, 747SP Series and 747SR Series - Effective: December 11, 1990 - Superseded by: [AD 2013-16-24](https://openairdocs.org/ad/2013-16-24) - Product type: Aircraft, Large airplane - Amendment: 39-6801 - Docket: 90-NM-110-AD - Registered aircraft: 63 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DAB8DEB27C592A24862569600072328B.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/90-23-14 ## The airworthiness directive 90-23-14 BOEING: Amendment 39-6801. Docket No. 90-NM-110-AD. Applicability: Model 747 series airplanes, identified in Boeing Service Bulletin 747-53- 2253, Revision 2, dated March 29, 1990, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent sudden loss of cabin pressurization and the inability to withstand fail-safe loads, accomplish the following: A. For airplanes that have not been modified in accordance with Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990: In accordance with the schedule indicated below, perform a high frequency eddy current inspection of the fuselage lap joint for cracks between body station (BS) 340 and BS 400, or aft as far as the crew door, at stringer (S)- 6L and S-6R, in accordance with Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990. 1. Inspection schedule: a. Unless previously accomplished within the last 2,750 landings, perform the initial inspection within the next 250 landings after the effective date of this AD, or prior to the accumulation of 10,000 landings, whichever occurs later. b. Repeat the inspection thereafter at intervals not to exceed 3,000 landings. 2. If cracks are found, repair prior to further flight, in accordance with Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990. B. For airplanes that have been modified in accordance with Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990: In accordance with the schedule below, perform a high frequency eddy current inspection of the fuselage lap joint for cracks between BS 340 and BS 400, or aft as far as the crew door, at stringers (S)-6L and S-6R, in accordance with Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990. 1. Inspection schedule: a. Unless previously accomplished within the last 2,750 landings, perform the initial inspection within the next 250 landings after the effective date of this AD, or prior to the accumulation of 10,000 landings after the modification, whichever occurs later. b. Repeat the inspection thereafter at intervals not to exceed 3,000 landings. 2. If cracks are found, repair prior to further flight, in accordance with Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990. C. For purposes of complying with this AD, the number of landings may be determined to be equal to the number of pressurization cycles where the cabin pressure differential was greater than 1.5 psi. D. For Model 747SR airplanes only: Based on a continued mixed operation of lower cabin differentials, the initial inspection thresholds and the repetitive inspection intervals specified in this AD may be multiplied by a 1.2 adjustment factor. 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, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle ACO. 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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington. Airworthiness Directive 90-23-14 supersedes AD 85-17-05, Amendment 39-5123. This amendment (39-6801, AD 90-23-14) becomes effectiveon December 11, 1990. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A20WE](https://openairdocs.org/tcds/A20WE): The Boeing Company; names 12 of 14 models: 747-100B Series, 747SP Series, 747-400D Series, 747-400F Series, 747-200B Series, 747-200F Series, 747-300 Series, 747-200C Series… ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 63 (63 by airframe model, 0 by engine model) - Makers: Boeing 63 Models with the most aircraft: - [Boeing 747-446](https://openairdocs.org/model/boeing-747-446): 10 aircraft (airframe model) - [Boeing 747-422](https://openairdocs.org/model/boeing-747-422): 8 aircraft (airframe model) - [Boeing 747-412](https://openairdocs.org/model/boeing-747-412): 5 aircraft (airframe model) - [Boeing 747-400F](https://openairdocs.org/model/boeing-747-400f): 4 aircraft (airframe model) - [Boeing 747-409](https://openairdocs.org/model/boeing-747-409): 4 aircraft (airframe model) - [Boeing 747-481F](https://openairdocs.org/model/boeing-747-481f): 3 aircraft (airframe model) - [Boeing 747-409F](https://openairdocs.org/model/boeing-747-409f): 3 aircraft (airframe model) - [Boeing 747-481](https://openairdocs.org/model/boeing-747-481): 3 aircraft (airframe model) - [Boeing 747-428F](https://openairdocs.org/model/boeing-747-428f): 3 aircraft (airframe model) - [Boeing 747-123](https://openairdocs.org/model/boeing-747-123): 2 aircraft (airframe model) - [Boeing 747-251F](https://openairdocs.org/model/boeing-747-251f): 2 aircraft (airframe model) - [Boeing 747-443](https://openairdocs.org/model/boeing-747-443): 2 aircraft (airframe model) - [Boeing 747-438](https://openairdocs.org/model/boeing-747-438): 2 aircraft (airframe model) - [Boeing 747-428](https://openairdocs.org/model/boeing-747-428): 2 aircraft (airframe model) - [Boeing 747-257B](https://openairdocs.org/model/boeing-747-257b): 1 aircraft (airframe model) - [Boeing 747-283B](https://openairdocs.org/model/boeing-747-283b): 1 aircraft (airframe model) - [Boeing 747-121](https://openairdocs.org/model/boeing-747-121): 1 aircraft (airframe model) - [Boeing 747-131](https://openairdocs.org/model/boeing-747-131): 1 aircraft (airframe model) - [Boeing 747-128](https://openairdocs.org/model/boeing-747-128): 1 aircraft (airframe model) - [Boeing 747-273C](https://openairdocs.org/model/boeing-747-273c): 1 aircraft (airframe model) All 24 models: https://openairdocs.org/ad/90-23-14/models.md Every aircraft: https://openairdocs.org/ad/90-23-14/aircraft.md ## Related documents - [AD 2013-16-24](https://openairdocs.org/ad/2013-16-24): Fuselage · Boeing 747-100 Series, 747-100B Series, 747-200B Series and 5 more. Effective Oct 9, 2013. Supersedes this AD Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.