# AD 90-12-02: Pneumatic System Check Valve Inspection - Type: Airworthiness directive - Status: Current - Products: Boeing 767-200 Series, 767-300 Series and 767-300F Series - Effective: June 18, 1990 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-6620 - Docket: 90-NM-82-AD - Registered aircraft: 402 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/32CF0F34381675C3862569600048624E.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/90-12-02 ## The airworthiness directive 90-12-02 BOEING: Amendment 39-6620. Docket No. 90-NM-82-AD. Applicability: Model 767 series airplanes, equipped with Hamilton Standard 8th stage bleed pneumatic system check valve, part number 773856, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent engine or pneumatic system damage caused by the failure of the pneumatic system 8th stage check valve, accomplish the following: A. Within the next 500 hours time-in-service after March 19, 1990 (the effective date of Amendment 39-6509), or prior to the accumulation of 1,200 hours time-in-service on the valve, or within 30 days after the effective date of this AD, whichever occurs later, perform the inspections of the 8th stage bleed pneumatic system check valve specified in Hamilton Standard Service Bulletin 36-2078, dated March 1, 1989, or Revision 1, dated August 15, 1989. Prior to further flight, repair or replace any check valves which do not pass allthe required inspections. Thereafter, inspect the check valve poppet at intervals not to exceed 1,200 hours time-in-service, in accordance with Hamilton Standard Service Bulletin 36-2078, Revision 1, dated August 15, 1989. B. Used check valves must be inspected and repaired, if necessary, in accordance with Hamilton Standard Service Bulletin 36-2078, dated March 1, 1989, or Revision 1, dated August 15, 1989, prior to installation in any Model 767 series airplane. C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may by used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Seattle Aircraft Certification Office. 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 information from the manufacturer may obtain copies upon request to the Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124, or Hamilton Standard, Division of United Technologies Corporation, Bradley Field Road, Windsor Locks, Connecticut 06096. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal South, Seattle, Washington. This AD supersedes AD 90-04-10, Amendment 39-6509 which superseded AD 87-12-07 (Amendment 39-5646), and AD 86-06-01 (Amendment 39-5257). This amendment (39-6620, AD 90-12-02) becomes effective on June 18, 1990. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A1NM](https://openairdocs.org/tcds/A1NM): The Boeing Company; names 3 of 5 models: 767-300 Series, 767-200 Series, 767-300F 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: 402 (402 by airframe model, 0 by engine model) - Makers: Boeing 402 Models with the most aircraft: - [Boeing 767-300F](https://openairdocs.org/model/boeing-767-300f): 169 aircraft (airframe model) - [Boeing 767-332](https://openairdocs.org/model/boeing-767-332): 46 aircraft (airframe model) - [Boeing 767-322](https://openairdocs.org/model/boeing-767-322): 36 aircraft (airframe model) - [Boeing 767-323](https://openairdocs.org/model/boeing-767-323): 27 aircraft (airframe model) - [Boeing 767-338](https://openairdocs.org/model/boeing-767-338): 13 aircraft (airframe model) - [Boeing 767-316](https://openairdocs.org/model/boeing-767-316): 12 aircraft (airframe model) - [Boeing 767-346](https://openairdocs.org/model/boeing-767-346): 11 aircraft (airframe model) - [Boeing 767-281](https://openairdocs.org/model/boeing-767-281): 9 aircraft (airframe model) - [Boeing 767-381](https://openairdocs.org/model/boeing-767-381): 8 aircraft (airframe model) - [Boeing 767-232](https://openairdocs.org/model/boeing-767-232): 6 aircraft (airframe model) - [Boeing 767-319](https://openairdocs.org/model/boeing-767-319): 6 aircraft (airframe model) - [Boeing 767-306](https://openairdocs.org/model/boeing-767-306): 5 aircraft (airframe model) - [Boeing 767-224](https://openairdocs.org/model/boeing-767-224): 5 aircraft (airframe model) - [Boeing 767-300](https://openairdocs.org/model/boeing-767-300): 5 aircraft (airframe model) - [Boeing 767-316F](https://openairdocs.org/model/boeing-767-316f): 5 aircraft (airframe model) - [Boeing 767-336](https://openairdocs.org/model/boeing-767-336): 4 aircraft (airframe model) - [Boeing 767-223](https://openairdocs.org/model/boeing-767-223): 3 aircraft (airframe model) - [Boeing 767-231](https://openairdocs.org/model/boeing-767-231): 3 aircraft (airframe model) - [Boeing 767-304](https://openairdocs.org/model/boeing-767-304): 3 aircraft (airframe model) - [Boeing 767-324](https://openairdocs.org/model/boeing-767-324): 3 aircraft (airframe model) All 36 models: https://openairdocs.org/ad/90-12-02/models.md Every aircraft: https://openairdocs.org/ad/90-12-02/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.