AD 82-16-09

final rule

Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters

AD Number
82-16-09
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of a helicopter rotor hub assembly
Problem area Rotor system

Applicability

TypeManufacturerModelDetails
aircraft Enstrom Helicopter Corporation, The 280 Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters
aircraft Enstrom Helicopter Corporation, The 280C Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters
aircraft Enstrom Helicopter Corporation, The 280F Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters
aircraft Enstrom Helicopter Corporation, The F-28A Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters
aircraft Enstrom Helicopter Corporation, The F-28C Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters
aircraft Enstrom Helicopter Corporation, The F-28F Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters

Unsafe Condition

Wear damage to main rotor blade grips and shim misalignment could lead to possible failure of the main rotor blade grips.

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

Required Actions

Inspect main rotor blade grips and shims for wear grooves, misalignment, and clearance. Replace shims if deformed or nonuniform, repair or replace grips based on wear groove depth, and reassemble per maintenance manual. Inspections required within 100 hours' time in service from AD effective date and every 200 hours thereafter.

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

Compliance Time

Within the next 100 hours' time in service from the effective date of this AD and thereafter at intervals not to exceed 200 hours' time in service from the last inspection.

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

Affected Aircraft

Enstrom Helicopter Corporation models F-28A, F-28C, F-28F, 280, 280C, and 280F helicopters certificated in all categories.

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

Federal Register Abstract

Main Rotor Blade Grips

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_82-16-09.html
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AD Number:
82-16-09
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 2...Show more
Subject:
Main Rotor Blade Grips
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
08/04/1982
Make:
Enstrom Helicopter Corporation, The
Model:
280 | 280C | 280F | F-28A | F-28C | F-28F
Product Type:
Aircraft
Product Subtype:
Rotorcraft
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 82-16-09
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4429

AD NUMBER:   82-16-09

SUBJECT HEADING:   Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective August 4, 1982.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
82-16-09 ENSTROM HELICOPTER CORPORATION: Amendment 39-4429. Applies to all Model F-28A, F-28C, F-28C, F-28F, 280, 280C, and 280F helicopters certificated in all categories.

Compliance required as indicated unless already accomplished. To detect wear damage and to prevent possible failure of the main rotor blade grips, accomplish the following:

Within the next 100 hours' time in service from the effective date of this AD and thereafter at intervals not to exceed 200 hours' time in service from the last inspection:

(a) Remove the main rotor blades per instructions in Section 6 of the maintenance manual.

CAUTION: To prevent damage to the Lamiflex bearing, it is important to comply with blade grip placard cautioning against over-rotation of the grip when the pitch link is disconnected.

(b) Remove Lamiflex thrust bearing cover assembly (P/N 28-14239).

(c) Remove any dirt, grease, or other abrasive material from the space around the Lamiflex thrust bearing.

(d) Inspect shim(s) (P/N 28-14293) for alignment/concentricity and clearance.

(1) The shim(s) must be concentric with the Lamiflex thrust bearing.

(2) Ascertain that the shim(s) do not protrude beyond the outer diameter of the Lamiflex bearing.

(e) Inspect blade grip (P/N 28-14279) inner faces for possible wear grooves.

(f) If there is shim misalignment, inadequate clearance, or wear grooves in grips, remove: cotter pin (P/N AN 380-4-8), retention nut (P/N 28-14335), shim(s) (P/N 28-14293), and Lamiflex thrust bearing (P/N 28-14310).

(g) Inspect blade grips having wear grooves to establish repairability. Grips having a wear-groove depth greater than .125 inch must be replaced. Grips having a wear-groove depth of .125 inch or less are repairable.

(h) Repair blade grips(s) by blending out groove(s) smoothly over a circular area having a diameter equal to the wear-groove length. Do not remove excessive material such that the resultant concave blended surface extends beyond the Lamiflex thrust bearing cover (P/N 28- 14239) allowing it to leak.

NOTE: To perform this blending operation, it may be necessary to remove the grip from the main rotor retention assembly. Remove the grip(s) per instructions in Section 6 of the maintenance manual.

(i) Inspect shim(s) for serviceability. Discard any shim that is deformed out-of- round, has a nonuniform thickness, or was removed from an assembly where grip wear grooves were discovered.

(j) Replace discarded shim(s) with new shim(s) of the same nominal thickness.

(k) Reassemble main rotor retention assembly and main rotor assembly in accordance with the instructions in Section 6 of the maintenance manual.

(l) Any equivalent method of compliance with this AD must be approved by the Chief, Chicago Aircraft Certification Office, Federal Aviation Administration, 2300 Devon Avenue, Des Plaines, Illinois 60018.

(m) In accordance with FAR 21.197, flight is permitted to a base where the inspection required by this AD may be accomplished.

This amendment becomes effective August 4, 1982.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_82-16-09.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
82-16-09
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 2...Show more
Subject:
Main Rotor Blade Grips
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
08/04/1982
Make:
Enstrom Helicopter Corporation, The
Model:
280 | 280C | 280F | F-28A | F-28C | F-28F
Product Type:
Aircraft
Product Subtype:
Rotorcraft
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 82-16-09
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4429

AD NUMBER:   82-16-09

SUBJECT HEADING:   Airworthiness Directives; ENSTROM HELICOPTER CORPORATION Model F-28A, F-28C, F-28F, 280, 280C, and 280F Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective August 4, 1982.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
82-16-09 ENSTROM HELICOPTER CORPORATION: Amendment 39-4429. Applies to all Model F-28A, F-28C, F-28C, F-28F, 280, 280C, and 280F helicopters certificated in all categories.

Compliance required as indicated unless already accomplished. To detect wear damage and to prevent possible failure of the main rotor blade grips, accomplish the following:

Within the next 100 hours' time in service from the effective date of this AD and thereafter at intervals not to exceed 200 hours' time in service from the last inspection:

(a) Remove the main rotor blades per instructions in Section 6 of the maintenance manual.

CAUTION: To prevent damage to the Lamiflex bearing, it is important to comply with blade grip placard cautioning against over-rotation of the grip when the pitch link is disconnected.

(b) Remove Lamiflex thrust bearing cover assembly (P/N 28-14239).

(c) Remove any dirt, grease, or other abrasive material from the space around the Lamiflex thrust bearing.

(d) Inspect shim(s) (P/N 28-14293) for alignment/concentricity and clearance.

(1) The shim(s) must be concentric with the Lamiflex thrust bearing.

(2) Ascertain that the shim(s) do not protrude beyond the outer diameter of the Lamiflex bearing.

(e) Inspect blade grip (P/N 28-14279) inner faces for possible wear grooves.

(f) If there is shim misalignment, inadequate clearance, or wear grooves in grips, remove: cotter pin (P/N AN 380-4-8), retention nut (P/N 28-14335), shim(s) (P/N 28-14293), and Lamiflex thrust bearing (P/N 28-14310).

(g) Inspect blade grips having wear grooves to establish repairability. Grips having a wear-groove depth greater than .125 inch must be replaced. Grips having a wear-groove depth of .125 inch or less are repairable.

(h) Repair blade grips(s) by blending out groove(s) smoothly over a circular area having a diameter equal to the wear-groove length. Do not remove excessive material such that the resultant concave blended surface extends beyond the Lamiflex thrust bearing cover (P/N 28- 14239) allowing it to leak.

NOTE: To perform this blending operation, it may be necessary to remove the grip from the main rotor retention assembly. Remove the grip(s) per instructions in Section 6 of the maintenance manual.

(i) Inspect shim(s) for serviceability. Discard any shim that is deformed out-of- round, has a nonuniform thickness, or was removed from an assembly where grip wear grooves were discovered.

(j) Replace discarded shim(s) with new shim(s) of the same nominal thickness.

(k) Reassemble main rotor retention assembly and main rotor assembly in accordance with the instructions in Section 6 of the maintenance manual.

(l) Any equivalent method of compliance with this AD must be approved by the Chief, Chicago Aircraft Certification Office, Federal Aviation Administration, 2300 Devon Avenue, Des Plaines, Illinois 60018.

(m) In accordance with FAR 21.197, flight is permitted to a base where the inspection required by this AD may be accomplished.

This amendment becomes effective August 4, 1982.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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