AD 91-20-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 747-100 Series | Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes |
| aircraft | The Boeing Company | 747-100B Series | Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes |
| aircraft | The Boeing Company | 747-100B SUD Series | Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes |
| aircraft | The Boeing Company | 747-200B Series | Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes |
| aircraft | The Boeing Company | 747-200C Series | Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes |
| aircraft | The Boeing Company | 747-200F Series | Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes |
Unsafe Condition
Cross connection of the engine nacelle fire extinguishing plumbing during maintenance could lead to failure of the fire extinguishing system to function properly.
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Required Actions
Conduct an inspection of the engine fire extinguishing system plumbing within 10 days after October 24, 1989, and after any maintenance that could cause mis-plumbing, following Boeing SB 747-26A2094, Rev 1. Correct discrepancies before further flight. Modify the system plumbing within 18 months after November 7, 1991, per Boeing SB 747-26-2162 to terminate repetitive inspections.
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Compliance Time
Within 10 days after October 24, 1989; within 18 months after November 7, 1991
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Affected Aircraft
Boeing Model 747-100 and -200 series airplanes manufactured prior to January 1, 1981, equipped with GE CF6-45/50 or Pratt & Whitney JT9D-70 engines, as listed in Boeing SB 747-26-2162.
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Federal Register Abstract
Engine Fire Extinguishing System
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_91-20-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 91-20-06 Document Type: AD Final Rules Docket Number: 91-NM-56-AD Subject Heading: Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes Subject: Engine Fire Extinguishing System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/07/1991 Make: The Boeing Company Model: 747-100 Series | 747-100B Series | 747-100B SUD Series | 747-200B Series | 747-200C Series | 747-200...Show more 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: 91-20-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 91-NM-56-AD AMENDMENT: 39-8040 AD NUMBER: 91-20-06 SUBJECT HEADING: Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes ACTION: SUMMARY: DATES: Effective November 7, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 91-20-06 BOEING: Amendment 39-8040. Docket 91-NM-56-AD. Supersedes AD 89-22-03. Applicability: Model 747-100 and -200 series airplanes, manufactured prior to January 1, 1981; equipped with General Electric CF6-45/50 or Pratt and Whitney JT9D-70 engines; as listed in Boeing Service Bulletin 747-26-2162, dated September 20, 1990, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To preclude cross connection of the engine nacelle fire extinguishing plumbing during maintenance, accomplish the following: A. Within 10 days after October 24, 1989 (the effective date of Amendment 39- 6353, AD 89-22-03), and thereafter, immediately following any maintenance action which could cause mis-plumbing, conduct an inspection of the engine fire extinguishing system plumbing in accordance with Boeing Service Bulletin 747-26A2094, Revision 1, dated March 25, 1983. B. Before further flight, correct any discrepancy detected during the functional tests required by paragraph A. of this AD. C. Within 18 months after the effective date of this amendment, modify the engine fire extinguisher system plumbing in accordance with Boeing Service Bulletin 747-26-2162, dated September 20, 1990. Accomplishment of this modification constitutes terminating action for the repetitive inspections required by paragraph A. of this AD. D. 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. E. 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. F. The modification shall be done in accordance with Boeing Service Bulletin 747- 26-2162, dated September 20, 1990. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington, or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C. Airworthiness Directive 91-20-06 supersedes AD 89-22-03, Amendment 39-6353. This amendment (39-8040, AD 91-20-06) becomes effective on November 7, 1991. FOOTER:
Document Text
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AD Final Rules - DRS_91-20-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 91-20-06 Document Type: AD Final Rules Docket Number: 91-NM-56-AD Subject Heading: Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes Subject: Engine Fire Extinguishing System Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/07/1991 Make: The Boeing Company Model: 747-100 Series | 747-100B Series | 747-100B SUD Series | 747-200B Series | 747-200C Series | 747-200...Show more 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: 91-20-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 91-NM-56-AD AMENDMENT: 39-8040 AD NUMBER: 91-20-06 SUBJECT HEADING: Airworthiness Directives; BOEING Model 747-100 and -200 Series Airplanes ACTION: SUMMARY: DATES: Effective November 7, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 91-20-06 BOEING: Amendment 39-8040. Docket 91-NM-56-AD. Supersedes AD 89-22-03. Applicability: Model 747-100 and -200 series airplanes, manufactured prior to January 1, 1981; equipped with General Electric CF6-45/50 or Pratt and Whitney JT9D-70 engines; as listed in Boeing Service Bulletin 747-26-2162, dated September 20, 1990, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To preclude cross connection of the engine nacelle fire extinguishing plumbing during maintenance, accomplish the following: A. Within 10 days after October 24, 1989 (the effective date of Amendment 39- 6353, AD 89-22-03), and thereafter, immediately following any maintenance action which could cause mis-plumbing, conduct an inspection of the engine fire extinguishing system plumbing in accordance with Boeing Service Bulletin 747-26A2094, Revision 1, dated March 25, 1983. B. Before further flight, correct any discrepancy detected during the functional tests required by paragraph A. of this AD. C. Within 18 months after the effective date of this amendment, modify the engine fire extinguisher system plumbing in accordance with Boeing Service Bulletin 747-26-2162, dated September 20, 1990. Accomplishment of this modification constitutes terminating action for the repetitive inspections required by paragraph A. of this AD. D. 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. E. 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. F. The modification shall be done in accordance with Boeing Service Bulletin 747- 26-2162, dated September 20, 1990. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington, or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C. Airworthiness Directive 91-20-06 supersedes AD 89-22-03, Amendment 39-6353. This amendment (39-8040, AD 91-20-06) becomes effective on November 7, 1991. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
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