AD 91-09-15

final rule

Airworthiness Directives; BOEING Model 767 Series Airplanes

AD Number
91-09-15
Status
final_rule
Effective Date
Product Category
aircraft
Docket
90-NM-250-AD
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 767-200 Series Airworthiness Directives; BOEING Model 767 Series Airplanes
aircraft The Boeing Company 767-300 Series Airworthiness Directives; BOEING Model 767 Series Airplanes
aircraft The Boeing Company 767-300F Series Airworthiness Directives; BOEING Model 767 Series Airplanes

Unsafe Condition

False oil filter bypass indication or loss of oil quantity from failed pressure switches.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Replace the engine oil filter differential pressure switch within 60 days after the effective date or prior to accumulating 10,000 total service hours, whichever is later. Subsequent replacements must occur at intervals not exceeding 10,000 total service hours. Removed switches cannot be reinstalled.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within the next 60 days after the effective date of this AD, or prior to the accumulation of 10,000 total service hours, whichever occurs later, and thereafter at intervals not to exceed 10,000 total service hours.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Boeing Model 767-200 Series, 767-300 Series, 767-300F Series airplanes equipped with engine oil filter differential pressure switches on JT9D-7R4 or PW4000 engines as listed in Boeing Service Bulletin 767-79-0008.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Oil Filter Pressure Switch

Applicability Source Text

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AD Number:
91-09-15
Document Type:
AD Final Rules
Docket Number:
90-NM-250-AD
Subject Heading:
Airworthiness Directives; BOEING Model 767 Series Airplanes
Subject:
Oil Filter Pressure Switch
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/28/1991
Make:
The Boeing Company
Model:
767-200 Series | 767-300 Series | 767-300F 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Superseded AD: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Superseded By: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: 91-09-15
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-250-AD

AMENDMENT:   39-6974

AD NUMBER:   91-09-15

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 767 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective May 28, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-09-15 BOEING: Amendment 39-6974. Docket No. 90-NM-250-AD.

Applicability: Model 767 series airplanes, as listed in Boeing Service Bulletin 767-79- 0008, dated August 11, 1988, equipped with engine oil filter differential pressure switches on JT9D-7R4 engines and all Model 767 series airplanes equipped with engine oil filter differential pressure switches on PW4000 engines, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent false oil filter bypass indication or loss of oil quantity from failed pressure switches, accomplish the following:

A. Within the next 60 days after the effective date of this AD, or prior to the accumulation of 10,000 total service hours, whichever occurs later, and thereafter at intervals not to exceed 10,000 total service hours, replace the engine oil filter differential pressure switch, as follows:

1. For Pratt & Whitney PW4000 engines: replace part number (P/N) S332T004-23 with a new -23 switch.

2. For Pratt & Whitney JT9D-7R4 engines: replace P/N's S332T004-2, - 25, or -29, with a new -29 switch. If a -2 or -25 switch is currently installed, modification in accordance with Boeing Service Bulletin 767-79-0008, dated August 11, 1988, is required in order to install a -29 switch configuration.

NOTE: Reworking, modifying, or overhauling a used switch does not zero time the switch.

B. Pressure switches removed following the accumulation of 10,000 total service hours shall not be re-installed on any airplane.

C. 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.

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 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 (39-6974, AD 91-09-15) becomes effective on May 28, 1991.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_91-09-15.html
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Details
AD Number:
91-09-15
Document Type:
AD Final Rules
Docket Number:
90-NM-250-AD
Subject Heading:
Airworthiness Directives; BOEING Model 767 Series Airplanes
Subject:
Oil Filter Pressure Switch
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/28/1991
Make:
The Boeing Company
Model:
767-200 Series | 767-300 Series | 767-300F 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: 91-09-15
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-250-AD

AMENDMENT:   39-6974

AD NUMBER:   91-09-15

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 767 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective May 28, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-09-15 BOEING: Amendment 39-6974. Docket No. 90-NM-250-AD.

Applicability: Model 767 series airplanes, as listed in Boeing Service Bulletin 767-79- 0008, dated August 11, 1988, equipped with engine oil filter differential pressure switches on JT9D-7R4 engines and all Model 767 series airplanes equipped with engine oil filter differential pressure switches on PW4000 engines, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent false oil filter bypass indication or loss of oil quantity from failed pressure switches, accomplish the following:

A. Within the next 60 days after the effective date of this AD, or prior to the accumulation of 10,000 total service hours, whichever occurs later, and thereafter at intervals not to exceed 10,000 total service hours, replace the engine oil filter differential pressure switch, as follows:

1. For Pratt & Whitney PW4000 engines: replace part number (P/N) S332T004-23 with a new -23 switch.

2. For Pratt & Whitney JT9D-7R4 engines: replace P/N's S332T004-2, - 25, or -29, with a new -29 switch. If a -2 or -25 switch is currently installed, modification in accordance with Boeing Service Bulletin 767-79-0008, dated August 11, 1988, is required in order to install a -29 switch configuration.

NOTE: Reworking, modifying, or overhauling a used switch does not zero time the switch.

B. Pressure switches removed following the accumulation of 10,000 total service hours shall not be re-installed on any airplane.

C. 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.

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 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 (39-6974, AD 91-09-15) becomes effective on May 28, 1991.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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