AD 90-21-13
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 747-100 Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-100B Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-100B SUD Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200B Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200C Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200F Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-300 Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-400 Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-400D Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-400F Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747SP Series | BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747SR Series | BOEING Model 747 Series Airplanes |
Unsafe Condition
Damage to hydraulic and pneumatic systems and flight deck/cabin air contamination
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Required Actions
Modify the hydraulic system in the number 2 and 3 struts in accordance with Boeing Service Bulletin 747-29-2051, Revision 1. An alternate means of compliance or adjustment may be used if approved by the FAA Manager. Special flight permits may be issued under FAR 21.197 and 21.199.
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Compliance Time
within the next 4,000 flight hours or 12 months after the effective date of this AD, whichever occurs first
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Affected Aircraft
Model 747 series airplanes, line position 001 through 331, identified in Boeing Service Bulletin 747-29-2051, Revision 1, dated August 8, 1980, certificated in any category
AI-generated summary from the source AD text. Verify against the official source before acting.
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_90-21-13.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-21-13 Document Type: AD Final Rules Docket Number: 90-NM-67-AD Subject Heading: BOEING Model 747 Series Airplanes Subject: Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/12/1990 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: 90-21-13 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 90-NM-67-AD AMENDMENT: 39-6751 AD NUMBER: 90-21-13 SUBJECT HEADING: BOEING Model 747 Series Airplanes ACTION: SUMMARY: DATES: Effective November 12, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-21-13 BOEING: Amendment 39-6751. Docket No. 90-NM-67-AD. Applicability: Model 747 series airplanes, line position 001 through 331, identified in Boeing Service Bulletin 747-29-2051, Revision 1, dated August 8, 1980, certificated in any category. Compliance: Required within the next 4,000 flight hours or 12 months after the effective date of this AD, whichever occurs first, unless previously accomplished. To prevent damage to hydraulic and pneumatic systems and flight deck/cabin air contamination, accomplish the following: A. Modify the hydraulic system in the number 2 and 3 struts in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-29-2051, Revision 1, dated August 8, 1980. B. An alternate means 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, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Inspector (PI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office. 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 The 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 S.W., Renton, Washington. This amendment (39-6751, AD 90-21-13) becomes effective on November 12, 1990. FOOTER:
Document Text
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AD Final Rules - DRS_90-21-13.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-21-13 Document Type: AD Final Rules Docket Number: 90-NM-67-AD Subject Heading: BOEING Model 747 Series Airplanes Subject: Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/12/1990 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: 90-21-13 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 90-NM-67-AD AMENDMENT: 39-6751 AD NUMBER: 90-21-13 SUBJECT HEADING: BOEING Model 747 Series Airplanes ACTION: SUMMARY: DATES: Effective November 12, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-21-13 BOEING: Amendment 39-6751. Docket No. 90-NM-67-AD. Applicability: Model 747 series airplanes, line position 001 through 331, identified in Boeing Service Bulletin 747-29-2051, Revision 1, dated August 8, 1980, certificated in any category. Compliance: Required within the next 4,000 flight hours or 12 months after the effective date of this AD, whichever occurs first, unless previously accomplished. To prevent damage to hydraulic and pneumatic systems and flight deck/cabin air contamination, accomplish the following: A. Modify the hydraulic system in the number 2 and 3 struts in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-29-2051, Revision 1, dated August 8, 1980. B. An alternate means 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, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Inspector (PI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office. 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 The 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 S.W., Renton, Washington. This amendment (39-6751, AD 90-21-13) becomes effective on November 12, 1990. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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