AD 60-07-01

final rule

ALLISON Models 501-D13D and 501-D13E Engines

AD Number
60-07-01
Status
final_rule
Effective Date
Product Category
engine
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft turbine engine assembly
Problem area Engine

Applicability

TypeManufacturerModelDetails
engine Rolls-Royce Corporation 501-D13D ALLISON Models 501-D13D and 501-D13E Engines
engine Rolls-Royce Corporation 501-D13E ALLISON Models 501-D13D and 501-D13E Engines

Unsafe Condition

Third stage turbine blade failures due to resonance at low speed ground idle, resulting in damage to fourth stage blades and vanes, and in one case failure of turbine inlet case-vane case split line bolts.

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

Required Actions

Aircraft without vibration detection equipment must limit low speed ground idle to 4 minutes total and inspect fourth stage turbine blades every 25 hours of operation. Aircraft with vibration detection must inspect blades upon arrival at the next maintenance base if vibrations exceed normal. Engines modified with P/N 6794773 blades are exempt.

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

Compliance Time

within the next 25 hours of operation

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

Affected Aircraft

Rolls-Royce Corporation Models 501-D13D and 501-D13E Engines

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

Federal Register Abstract

Low Speed Ground Idle

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_60-07-01.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
60-07-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
ALLISON Models 501-D13D and 501-D13E Engines
Subject:
Low Speed Ground Idle
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Rolls-Royce Corporation
Model:
501-D13D | 501-D13E
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 60-07-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   60-07-01

SUBJECT HEADING:   ALLISON Models 501-D13D and 501-D13E Engines

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
60-07-01 ALLISON: Amdt. 124 Part 507 Federal Register March 29, 1960. Applies to Models 501-D13D and 501-D13E Engines.

Compliance required within the next 25 hours of operation.

A few cases of third stage turbine blade failures have occurred due to a resonance condition at low speed ground idle. All of these failures to date have resulted in visible damage to fourth stage blades as well as fourth stage vanes. In one case continued operation of an engine with a failed blade resulted in failure of the turbine inlet case-vane case split line bolts.

(a) Aircraft not having operating engine vibration detection equipment must observe the following engine operating restriction and inspection.

(1) Low speed ground idle operation from time all engines are started to stopping all engines at end of flight not to exceed 4 minutes total time.

(2) Conduct inspection of fourth stage turbine blades at intervals not to exceed 25 hours of operation for indications of damage using adequate light and optical aid.

(b) Aircraft having operating engine vibration detection equipment shall use this equipment to detect any indications above normal and if found, the above inspection of fourth stage turbine blades shall be conducted upon arrival at the next maintenance base. If any damage is discovered as a result of (a) or (b) it is cause for more detailed inspection and/or engine removal.

(c) This restriction will not apply to engines modified in accordance with Allison Commercial Engine Bulletin No. 72-77 by installation of third stage turbine blades P/N 6794773 identified by a stripe of heat and corrosion resistant aluminum polytherm paint 1/2-inch wide and 4 inches long around contour of the inlet casing clockwise starting at the 1:00 position forward of the terminal block mounting flange.

(Allison Commercial Engine Bulletin No. 72-77 covers the same subject.)

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_60-07-01.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
60-07-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
ALLISON Models 501-D13D and 501-D13E Engines
Subject:
Low Speed Ground Idle
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Rolls-Royce Corporation
Model:
501-D13D | 501-D13E
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 60-07-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   60-07-01

SUBJECT HEADING:   ALLISON Models 501-D13D and 501-D13E Engines

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
60-07-01 ALLISON: Amdt. 124 Part 507 Federal Register March 29, 1960. Applies to Models 501-D13D and 501-D13E Engines.

Compliance required within the next 25 hours of operation.

A few cases of third stage turbine blade failures have occurred due to a resonance condition at low speed ground idle. All of these failures to date have resulted in visible damage to fourth stage blades as well as fourth stage vanes. In one case continued operation of an engine with a failed blade resulted in failure of the turbine inlet case-vane case split line bolts.

(a) Aircraft not having operating engine vibration detection equipment must observe the following engine operating restriction and inspection.

(1) Low speed ground idle operation from time all engines are started to stopping all engines at end of flight not to exceed 4 minutes total time.

(2) Conduct inspection of fourth stage turbine blades at intervals not to exceed 25 hours of operation for indications of damage using adequate light and optical aid.

(b) Aircraft having operating engine vibration detection equipment shall use this equipment to detect any indications above normal and if found, the above inspection of fourth stage turbine blades shall be conducted upon arrival at the next maintenance base. If any damage is discovered as a result of (a) or (b) it is cause for more detailed inspection and/or engine removal.

(c) This restriction will not apply to engines modified in accordance with Allison Commercial Engine Bulletin No. 72-77 by installation of third stage turbine blades P/N 6794773 identified by a stripe of heat and corrosion resistant aluminum polytherm paint 1/2-inch wide and 4 inches long around contour of the inlet casing clockwise starting at the 1:00 position forward of the terminal block mounting flange.

(Allison Commercial Engine Bulletin No. 72-77 covers the same subject.)

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.