AD 90-23-10
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | DC-9-81 (MD-81) | Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Series Airplanes and MD-88 Airplanes |
| aircraft | The Boeing Company | DC-9-82 (MD-82) | Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Series Airplanes and MD-88 Airplanes |
| aircraft | The Boeing Company | DC-9-83 (MD-83) | Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Series Airplanes and MD-88 Airplanes |
| aircraft | The Boeing Company | DC-9-87 (MD-87) | Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Series Airplanes and MD-88 Airplanes |
| aircraft | The Boeing Company | MD-88 | Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Series Airplanes and MD-88 Airplanes |
Unsafe Condition
Dual hydraulic system failure due to Whittaker Controls PTU shutoff valve (P/N 240695 or 240695-1) failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace PTU S/O valve attachment screws with P/N NAS 1101E-14; replace PTU S/O valve P/N 240695/240695-1 with P/N 240695-2 or modify via specified service bulletins. Compliance timelines vary based on valve part number.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 90 days or 180 days after December 10, 1990, depending on valve part number. For P/N 240695, also prior to 2,000 landings or within 200 landings after October 23, 1989, whichever is later.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87) series and MD-88 airplanes with Whittaker Controls PTU S/O valve P/N 240695, 240695-1, or 240695-2.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
PTU Shut-Off Valve
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_90-23-10.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-23-10 Document Type: AD Final Rules Docket Number: 89-NM-215-AD Subject Heading: Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and D...Show more Subject: PTU Shut-Off Valve Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/10/1990 Make: The Boeing Company Model: DC-9-81 (MD-81) | DC-9-82 (MD-82) | DC-9-83 (MD-83) | DC-9-87 (MD-87) | MD-88 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: 90-23-10 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 89-NM-215-AD AMENDMENT: 39-6798 AD NUMBER: 90-23-10 SUBJECT HEADING: Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Series Airplanes and MD-88 Airplanes ACTION: SUMMARY: DATES: Effective December 10, 1990 ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-23-10 MCDONNELL DOUGLAS: Amendment 39-6798. Docket No. 89-NM-215-AD. Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes and Model MD-88 airplanes; equipped with Whittaker Controls power transfer unit shutoff (PTU S/O) valve, Part Number (P/N) 240695 or P/N 240695-1; certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent dual hydraulic system failure, accomplish the following: A. For those airplanes with Whittaker Controls PTU S/O valve P/N 240695 installed, 1. Prior to the accumulation of 2,000 landings, or within 200 landings after October 23, 1989 (the effective date of Amendment 39-6356, AD 89-22-02), whichever occurs later, unless accomplished within the last 1,800 landings, replace the PTU S/O valve body attachment screws, P/N NAS 1101E-14, with new screws of the same part number, in accordance with the installation instructions of McDonnell Douglas Telex MD-80-COM-24/JCE, dated September 18, 1989. Thereafter, replace the attachment screws at intervals not to exceed 2,000 landings until replacement of the valves in accordance with paragraph A.2. of this AD is accomplished. Replacement of Whittaker Controls PTU S/O valve P/N 240695, with PTU S/O valve P/N 240695-2 constitutes terminating action for the requirements of this paragraph. 2. Within 90 days after the effective date of this amendment, replace all Whittaker Controls PTU S/O valves P/N 240695, with Whittaker Controls PTU S/O valves P/N 240695-2; or modify the valves P/N 240695 to the P/N 240695-2 configuration in accordance with Whittaker Controls Service Bulletin 240695-29-1, dated March 15, 1988, and Service Bulletin 240695-29-3, dated May 14, 1990. (Accomplishment of the procedures specified in both service bulletins is required.) B. For those airplanes with the Whittaker Controls PTU S/O valve P/N 240695-1 installed, within 180 days after the effective date of this amendment, replace all Whittaker Controls PTU S/O valve P/N 240695-1, with PTU S/O valve P/N 240695-2; or modify the valve P/N 240695-1 to the P/N 240695-2 configuration in accordance with Whittaker Controls Service Bulletin 240695-29-3, dated May 14, 1990. C. 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, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. NOTE: The request should be submitted directly to the Manager, Los Angeles ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Los Angeles ACO. 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 documents from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90801, ATTN: Business Unit Manager, Technical Publications, C1-HCW (54-60); or from Whittaker Controls, 12838 Saticoy Street, North Hollywood, California 91605. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington, or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California. Airworthiness Directive 90-23-10 supersedes AD 89-22-02, Amendment 39-6356. This amendment (39-6798, AD 90-23-10) becomes effective on December 10, 1990. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_90-23-10.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-23-10 Document Type: AD Final Rules Docket Number: 89-NM-215-AD Subject Heading: Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and D...Show more Subject: PTU Shut-Off Valve Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/10/1990 Make: The Boeing Company Model: DC-9-81 (MD-81) | DC-9-82 (MD-82) | DC-9-83 (MD-83) | DC-9-87 (MD-87) | MD-88 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: 90-23-10 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 89-NM-215-AD AMENDMENT: 39-6798 AD NUMBER: 90-23-10 SUBJECT HEADING: Airworthiness Directives; MCDONNELL DOUGLAS DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Series Airplanes and MD-88 Airplanes ACTION: SUMMARY: DATES: Effective December 10, 1990 ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-23-10 MCDONNELL DOUGLAS: Amendment 39-6798. Docket No. 89-NM-215-AD. Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes and Model MD-88 airplanes; equipped with Whittaker Controls power transfer unit shutoff (PTU S/O) valve, Part Number (P/N) 240695 or P/N 240695-1; certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent dual hydraulic system failure, accomplish the following: A. For those airplanes with Whittaker Controls PTU S/O valve P/N 240695 installed, 1. Prior to the accumulation of 2,000 landings, or within 200 landings after October 23, 1989 (the effective date of Amendment 39-6356, AD 89-22-02), whichever occurs later, unless accomplished within the last 1,800 landings, replace the PTU S/O valve body attachment screws, P/N NAS 1101E-14, with new screws of the same part number, in accordance with the installation instructions of McDonnell Douglas Telex MD-80-COM-24/JCE, dated September 18, 1989. Thereafter, replace the attachment screws at intervals not to exceed 2,000 landings until replacement of the valves in accordance with paragraph A.2. of this AD is accomplished. Replacement of Whittaker Controls PTU S/O valve P/N 240695, with PTU S/O valve P/N 240695-2 constitutes terminating action for the requirements of this paragraph. 2. Within 90 days after the effective date of this amendment, replace all Whittaker Controls PTU S/O valves P/N 240695, with Whittaker Controls PTU S/O valves P/N 240695-2; or modify the valves P/N 240695 to the P/N 240695-2 configuration in accordance with Whittaker Controls Service Bulletin 240695-29-1, dated March 15, 1988, and Service Bulletin 240695-29-3, dated May 14, 1990. (Accomplishment of the procedures specified in both service bulletins is required.) B. For those airplanes with the Whittaker Controls PTU S/O valve P/N 240695-1 installed, within 180 days after the effective date of this amendment, replace all Whittaker Controls PTU S/O valve P/N 240695-1, with PTU S/O valve P/N 240695-2; or modify the valve P/N 240695-1 to the P/N 240695-2 configuration in accordance with Whittaker Controls Service Bulletin 240695-29-3, dated May 14, 1990. C. 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, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. NOTE: The request should be submitted directly to the Manager, Los Angeles ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Los Angeles ACO. 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 documents from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90801, ATTN: Business Unit Manager, Technical Publications, C1-HCW (54-60); or from Whittaker Controls, 12838 Saticoy Street, North Hollywood, California 91605. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington, or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California. Airworthiness Directive 90-23-10 supersedes AD 89-22-02, Amendment 39-6356. This amendment (39-6798, AD 90-23-10) becomes effective on December 10, 1990. 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.