AD 82-03-02

final rule

DETROIT DIESEL ALLISON Model 250-C28B Engines

AD Number
82-03-02
Status
final_rule
Effective Date
Product Category
engine
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
engine Rolls-Royce Corporation 250-C28B DETROIT DIESEL ALLISON Model 250-C28B Engines

Unsafe Condition

Possible engine power loss resulting from intermittent or spurious activation of the N2 (Electronic) Overspeed Control System.

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

Required Actions

Disarm the N2 Overspeed Circuit Breaker by pulling it and securing with tape or a Ty-wrap. Install a placard stating 'ENG OVSP CIRCUIT DEACTIVATED' near the breaker. Install P/N AN814-4DL or Alternate Plug with P/N AS3084-04 Packing in the N2 Overspeed Solenoid Valve outlet port, tightened and safety-wired.

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

Compliance Time

before further flight

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

Affected Aircraft

All Model 250-C28B engines installed in, but not limited to, Bell Model 206L-1 rotorcraft certificated in all categories.

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

Federal Register Abstract

N2 (Electronic) Overspeed Control System

Applicability Source Text

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Details
AD Number:
82-03-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
DETROIT DIESEL ALLISON Model 250-C28B Engines
Subject:
N2 (Electronic) Overspeed Control System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
02/04/1982
Make:
Rolls-Royce Corporation
Model:
250-C28B
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Superseded AD: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Superseded By: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: 82-03-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4305

AD NUMBER:   82-03-02

SUBJECT HEADING:   DETROIT DIESEL ALLISON Model 250-C28B Engines

ACTION:  

SUMMARY:  

DATES:   Effective February 4, 1982.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   82-03-02 DETROIT DIESEL ALLISON: Amendment 39-4305. Applies to all Model 250-C28B engines installed in, but not limited to, Bell Model 206L-1 rotorcraft certificated in all categories.
Compliance is required as indicated, unless previously accomplished. To preclude possible engine power loss resulting from intermittent or spurious activation of the N2 (Electronic) Overspeed Control System, accomplish the following before further flight:
(1) Disarm the aircraft installed engine N2 Overspeed Circuit Breaker by pulling the N2 Overspeed Circuit Breaker and secure by wrapping with tape or placing a Ty-wrap (or equivalent plastic tie strap) around the breaker stem.
(2) Install placard which states: "ENG OVSP CIRCUIT DEACTIVATED" in 1/4" or larger letters adjacent to N2 Overspeed Circuit Breaker. NOTE: The engine electronic overspeed test and the engine electronic overspeed trip system outlined in the rotorcraft Flight Manual will no longer function with the circuit breaker deactivated.
(3) Install a P/N AN814-4DL or Alternate Plug and P/N AS3084-04 Packing in the outlet port of the N2 Overspeed Solenoid Valve. Tighten and safety with lockwire. NOTE: This action further assures deactivation of the N2 (Electronic) Overspeed Control System. Primary overspeed protection is still provided by the mechanical power turbine fuel governor.
Upon request of the operator, an equivalent means of compliance with the requirements of this AD may be approved by the Chief, Chicago Aircraft Certification Office, Federal Aviation Administration, Central Region.
NOTE: Detroit Diesel Allison Commercial Engine Alert Bulletin CEB-A-73-2020 refers to this subject.
This amendment becomes effective February 4, 1982.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_82-03-02.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
82-03-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
DETROIT DIESEL ALLISON Model 250-C28B Engines
Subject:
N2 (Electronic) Overspeed Control System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
02/04/1982
Make:
Rolls-Royce Corporation
Model:
250-C28B
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: 82-03-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4305

AD NUMBER:   82-03-02

SUBJECT HEADING:   DETROIT DIESEL ALLISON Model 250-C28B Engines

ACTION:  

SUMMARY:  

DATES:   Effective February 4, 1982.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   82-03-02 DETROIT DIESEL ALLISON: Amendment 39-4305. Applies to all Model 250-C28B engines installed in, but not limited to, Bell Model 206L-1 rotorcraft certificated in all categories.
Compliance is required as indicated, unless previously accomplished. To preclude possible engine power loss resulting from intermittent or spurious activation of the N2 (Electronic) Overspeed Control System, accomplish the following before further flight:
(1) Disarm the aircraft installed engine N2 Overspeed Circuit Breaker by pulling the N2 Overspeed Circuit Breaker and secure by wrapping with tape or placing a Ty-wrap (or equivalent plastic tie strap) around the breaker stem.
(2) Install placard which states: "ENG OVSP CIRCUIT DEACTIVATED" in 1/4" or larger letters adjacent to N2 Overspeed Circuit Breaker. NOTE: The engine electronic overspeed test and the engine electronic overspeed trip system outlined in the rotorcraft Flight Manual will no longer function with the circuit breaker deactivated.
(3) Install a P/N AN814-4DL or Alternate Plug and P/N AS3084-04 Packing in the outlet port of the N2 Overspeed Solenoid Valve. Tighten and safety with lockwire. NOTE: This action further assures deactivation of the N2 (Electronic) Overspeed Control System. Primary overspeed protection is still provided by the mechanical power turbine fuel governor.
Upon request of the operator, an equivalent means of compliance with the requirements of this AD may be approved by the Chief, Chicago Aircraft Certification Office, Federal Aviation Administration, Central Region.
NOTE: Detroit Diesel Allison Commercial Engine Alert Bulletin CEB-A-73-2020 refers to this subject.
This amendment becomes effective February 4, 1982.

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.