AD 80-01-08

final rule

Airworthiness Directives; Piper Models PA-31T Airplanes

AD Number
80-01-08
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Piper Aircraft Inc. PA-31T Airworthiness Directives; Piper Models PA-31T Airplanes
aircraft Piper Aircraft Inc. PA-31T1 Airworthiness Directives; Piper Models PA-31T Airplanes

Unsafe Condition

Leakage of the oil cooler inlet hose assembly, P/N 80026-05, causing oil loss and potential inflight engine shutdown.

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

Required Actions

Remove engine cowlings and oil cooler inlet hose, inspect steel braiding for kinking, pressure test hose to 500 psi using dry nitrogen, replace hose if kinking or leakage is found, install new band clamp if no issues, reinstall components with proper support clamp, and verify no oil leaks after engine run.

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

Compliance Time

within the next 25 hours of operation as indicated unless already accomplished

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

Affected Aircraft

Piper Models PA-31T serial numbers 31T-7920001 thru 7920068, 7920070 thru 7920080; and PA-31T1 serial numbers 31T-7904001 thru 7904044.

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

Federal Register Abstract

Oil Cooler Inlet Hose Assembly

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_80-01-08.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
80-01-08
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Piper Models PA-31T Airplanes
Subject:
Oil Cooler Inlet Hose Assembly
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
01/10/1980
Effective Date:
01/14/1980
Make:
Piper Aircraft Inc.
Model:
PA-31T | PA-31T1
Product Type:
Aircraft
Product Subtype:
Small Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
AIR-700: Compliance & Airworthiness Division
Office of Primary Responsibility:
AIR-720: Operational Safety Branch
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 80-01-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3653

AD NUMBER:   80-01-08

SUBJECT HEADING:   Airworthiness Directives; Piper Models PA-31T Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective January 14, 1980.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
80-01-08 PIPER: Amendment 39-3653. Applies to Models PA-31T serial numbers 31T-7920001 thru 7920068, 7920070 thru 7920080; and PA-31T1 serial numbers 31T-7904001 thru 7904044.

Compliance required within the next 25 hours of operation as indicated unless already accomplished.

To preclude the necessity of inflight engine shutdown due to oil loss caused by leakage of the oil cooler inlet hose assembly, accomplish the following on each engine:

Remove engine cowlings and remove oil cooler inlet hose, P/N 80026-05. Cap engine outlet immediately upon removal of hose. Remove the band clamp from the 90-degree fitting end of the fire sleeve and pull fire sleeve back as far as possible to inspect steel braiding for kinking. If kinking is found, replace hose. (Note: Kinking will usually be noticed on the steel braiding between the midpoint of the hose and the 90-degree fitting end.)

If no evidence of kinking is found and with band clamp still removed, pressure test hose to 500 psi using dry nitrogen with hose submerged in water. (Note: A suitable pressure test arrangement is to cap both ends of the hose with appropriate AN hardware items, one of which has been drilled and fitted with a Schrader valve.) If leakage is observed, replace hose with a new oil inlet hose, P/N 80026-05. If test indicates no leakage, install new band clamp on fire sleeve. Reinstall tested hose or new hose as required per above instructions. Reinstall support clamp, maintaining the maximum possible bend ratios to prevent kinking of hose, check engine oil supply, and replenish if necessary. Run engine; insure that no oil leaks exist, and reinstall cowling.

Equivalent methods of compliance must be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration (FAA), Eastern Region. As permitted by FAR 21.197, aircraft may be flown to a base where maintenance required by this Airworthiness Directive can be accomplished.

Piper Telex F.L. 31-22A dated August 17, 1979, and Emergency Airworthiness Directive dated August 13, 1979, pertain to this subject.

This amendment is effective January 14, 1980, and was effective upon receipt by all addressees of an airmail letter, dated August 13, 1979, on this same matter.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_80-01-08.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
80-01-08
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Piper Models PA-31T Airplanes
Subject:
Oil Cooler Inlet Hose Assembly
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
01/10/1980
Effective Date:
01/14/1980
Make:
Piper Aircraft Inc.
Model:
PA-31T | PA-31T1
Product Type:
Aircraft
Product Subtype:
Small Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
AIR-700: Compliance & Airworthiness Division
Office of Primary Responsibility:
AIR-720: Operational Safety Branch
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 80-01-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-3653

AD NUMBER:   80-01-08

SUBJECT HEADING:   Airworthiness Directives; Piper Models PA-31T Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective January 14, 1980.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
80-01-08 PIPER: Amendment 39-3653. Applies to Models PA-31T serial numbers 31T-7920001 thru 7920068, 7920070 thru 7920080; and PA-31T1 serial numbers 31T-7904001 thru 7904044.

Compliance required within the next 25 hours of operation as indicated unless already accomplished.

To preclude the necessity of inflight engine shutdown due to oil loss caused by leakage of the oil cooler inlet hose assembly, accomplish the following on each engine:

Remove engine cowlings and remove oil cooler inlet hose, P/N 80026-05. Cap engine outlet immediately upon removal of hose. Remove the band clamp from the 90-degree fitting end of the fire sleeve and pull fire sleeve back as far as possible to inspect steel braiding for kinking. If kinking is found, replace hose. (Note: Kinking will usually be noticed on the steel braiding between the midpoint of the hose and the 90-degree fitting end.)

If no evidence of kinking is found and with band clamp still removed, pressure test hose to 500 psi using dry nitrogen with hose submerged in water. (Note: A suitable pressure test arrangement is to cap both ends of the hose with appropriate AN hardware items, one of which has been drilled and fitted with a Schrader valve.) If leakage is observed, replace hose with a new oil inlet hose, P/N 80026-05. If test indicates no leakage, install new band clamp on fire sleeve. Reinstall tested hose or new hose as required per above instructions. Reinstall support clamp, maintaining the maximum possible bend ratios to prevent kinking of hose, check engine oil supply, and replenish if necessary. Run engine; insure that no oil leaks exist, and reinstall cowling.

Equivalent methods of compliance must be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration (FAA), Eastern Region. As permitted by FAR 21.197, aircraft may be flown to a base where maintenance required by this Airworthiness Directive can be accomplished.

Piper Telex F.L. 31-22A dated August 17, 1979, and Emergency Airworthiness Directive dated August 13, 1979, pertain to this subject.

This amendment is effective January 14, 1980, and was effective upon receipt by all addressees of an airmail letter, dated August 13, 1979, on this same matter.

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.