# AD 78-08-04: Outflow Valve Assemblies - 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Series, 747-400 Series, 747-400D Series, 747-400F Series, 747SP Series and 747SR Series - Effective: May 10, 1978 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-3187 - Registered aircraft: 63 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B0BE02D64E7E722B86256839004FFB58.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/78-08-04 ## The airworthiness directive 78-08-04 BOEING: Amendment 39-3187. Applies to Model 747 series airplanes certificated in all categories and equipped with pressurization system outflow valve assemblies, Boeing P/N 60B00025-3, -11, -12, and -17 (Hamilton Standard P/N 719201-2, -3, -4, -5, -6, -7, - 8, and -9). Compliance required as indicated. To prevent rapid loss of pressurization in flight accomplish the following: A. Within 350 hours time in service after the effective date of this airworthiness directive, unless already accomplished, and thereafter at intervals not to exceed 900 hours time in service until modified in accordance with part B of this airworthiness directive, inspect forward and aft gates of each outflow valve assembly in accordance with the instructions contained in Boeing Service Bulletin No. 747-21-2139, Revision 1 dated April 7, 1978, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. Gates found with delamination or cracks in the hinge-to-gate bonds must be removed and replaced with a part free of delamination or cracks. Removed gates may be forwarded to Hamilton Standard for further evaluation or modified in accordance with part B of this airworthiness directive, as applicable, prior to being returned to service. B. Within 4000 hours time in service after the effective date of this airworthiness directive, modify the outflow valve assemblies in accordance with the instructions contained in Hamilton Standard Service Bulletin H.S. Code 747 AC-114, Revision 1 dated March 15, 1978, or later FAA approved revision, or by an equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. C. Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, may adjust the inspection compliance time and/or modification compliance time specified in this airworthiness directive to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). AD 77-25-06, Amendment 39-3098 (42 FR 63637) is hereby superseded. This amendment becomes effective May 10, 1978. ## 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/78-08-04/models.md Every aircraft: https://openairdocs.org/ad/78-08-04/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.