# AD 88-05-07: Auxiliary Power Unit Drain System - Type: Airworthiness directive - Status: Current - 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Series, 747-400 Series, 747-400D Series, 747-400F Series, 747SP Series and 747SR Series - Effective: March 25, 1988 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-5867 - Registered aircraft: 63 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2E28CCD1104D06CE8625695900729231.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/88-05-07 ## The airworthiness directive 88-05-07 BOEING: Amendment 39-5867. Applies to Model 747 series airplanes, as listed in Boeing Service Bulletin 747-49-2051, dated November 5, 1987, certificated in any category. Compliance required as indicated, unless previously accomplished. To eliminate the potential for a fire due to fuel leaking from the auxiliary power unit (APU) drain system, accomplish the following: A. Within the next 30 days after the effective date of this AD, and at intervals not to exceed 30 days thereafter, inspect the APU fuel supply line for fuel leaks, in accordance with Boeing Model 747 Maintenance Manual Section 28-25-00, page 601, dated August 25, 1987, or later FAA-approved revision. If leakage is detected, repair in accordance with the Maintenance Manual, before further flight. B. Modification of the APU fuel line drain system, fuel pump drain, and turbine drain assembly, in accordance with Boeing Service Bulletin 747-49-2051, dated November 5, 1987, or later FAA-approvedrevision, constitutes terminating action for the repetitive inspection requirement of paragraph A., above. C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety and which has the concurrence of an FAA Principal Maintenance Inspector, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. D. 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 the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. This information may be examined at FAA, 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 March 25, 1988. ## 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/88-05-07/models.md Every aircraft: https://openairdocs.org/ad/88-05-07/aircraft.md 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.