AD 91-12-15
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 757-200 Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
| aircraft | The Boeing Company | 757-200CB Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
| aircraft | The Boeing Company | 757-200PF Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
| aircraft | The Boeing Company | 757-300 Series | Airworthiness Directives; BOEING Model 757 Series Airplanes |
Unsafe Condition
Loss of fluid from all three hydraulic systems due to unincorporated Production Revision Release (PRR) 53736.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Modify the center hydraulic system per Boeing Alert Service Bulletin 757-29A0030, Revision 3. Alternative methods of compliance or adjustments may be approved by the Manager, Seattle Aircraft Certification Office. Special flight permits may be issued under FAR 21.197 and 21.199.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 3,600 hours time-in-service or 24 calendar months after the effective date of this AD, whichever occurs later
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
BOEING Model 757 series airplanes, line numbers 001 through 199, on which Production Revision Release (PRR) 53736 has not been incorporated
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Hydraulic Systems
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_91-12-15.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 91-12-15 Document Type: AD Final Rules Docket Number: 90-NM-36-AD Subject Heading: Airworthiness Directives; BOEING Model 757 Series Airplanes Subject: Hydraulic Systems Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/15/1991 Make: The Boeing Company Model: 757-200 Series | 757-200CB Series | 757-200PF Series | 757-300 Series Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 91-12-15 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 90-NM-36-AD AMENDMENT: 39-7027 AD NUMBER: 91-12-15 SUBJECT HEADING: Airworthiness Directives; BOEING Model 757 Series Airplanes ACTION: SUMMARY: DATES: Effective July 15, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 91-12-15 BOEING: Amendment 39-7027. Docket No. 90-NM-36-AD. Applicability: Model 757 series airplanes, line numbers 001 through 199, on which Production Revision Release (PRR) 53736 has not been incorporated, certificated in any category. Compliance: Required within the next 3,600 hours time-in-service or 24 calendar months after the effective date of this AD, whichever occurs later, unless previously accomplished. To prevent loss of fluid from all three hydraulic systems, accomplish the following: A. Modify the center hydraulic system in accordance with the instructions contained in Boeing Alert Service Bulletin 757-29A0030, Revision 3, dated February 7, 1991. B. An alternative method 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 forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO. C. 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 SW., Renton, Washington. This amendment (39-7027, AD 91-12-15) becomes effective on July 15, 1991. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_91-12-15.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 91-12-15 Document Type: AD Final Rules Docket Number: 90-NM-36-AD Subject Heading: Airworthiness Directives; BOEING Model 757 Series Airplanes Subject: Hydraulic Systems Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/15/1991 Make: The Boeing Company Model: 757-200 Series | 757-200CB Series | 757-200PF Series | 757-300 Series Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 91-12-15 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 90-NM-36-AD AMENDMENT: 39-7027 AD NUMBER: 91-12-15 SUBJECT HEADING: Airworthiness Directives; BOEING Model 757 Series Airplanes ACTION: SUMMARY: DATES: Effective July 15, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 91-12-15 BOEING: Amendment 39-7027. Docket No. 90-NM-36-AD. Applicability: Model 757 series airplanes, line numbers 001 through 199, on which Production Revision Release (PRR) 53736 has not been incorporated, certificated in any category. Compliance: Required within the next 3,600 hours time-in-service or 24 calendar months after the effective date of this AD, whichever occurs later, unless previously accomplished. To prevent loss of fluid from all three hydraulic systems, accomplish the following: A. Modify the center hydraulic system in accordance with the instructions contained in Boeing Alert Service Bulletin 757-29A0030, Revision 3, dated February 7, 1991. B. An alternative method 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 forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO. C. 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 SW., Renton, Washington. This amendment (39-7027, AD 91-12-15) becomes effective on July 15, 1991. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.