AD 74-12-01

AD Final Rules - DRS_74-12-01.html
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AD Number:
74-12-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Enstrom Models F-28 and F-28A Helicopters
Subject:
Forged Idler Yoke
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
09/04/1974
Make:
Enstrom Helicopter Corporation, The
Model:
F-28 | F-28A
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Superseded AD: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Superseded By: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: 74-12-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-1940

AD NUMBER:   74-12-01

SUBJECT HEADING:   Airworthiness Directives; Enstrom Models F-28 and F-28A Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective September 4, 1974.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
74-12-01 ENSTROM: Amendment 39-1856 as amended by Amendment 39-1940. Applies to Models F-28 and F-28A helicopters:

Compliance: Required as indicated, unless already accomplished.

To prevent failure of the forged idler yoke (P/N 28-13223)

(a) Before further flight and every 10 hours' time in service thereafter inspect by dye penetrant inspection method the webbed area of the forged idler yoke P/N 28-13223 for cracks. A forged idler yoke can be distinctively identified by the Part Number 28-13223 forged in 1/4 inch raised numbers on one side of the barrel portion and the alloy number MMT2014 forged in raised letters on the other side.

(b) As part of each pilot preflight inspection (logbook entry not required), the owner/operator is required to visually inspect the webbed area of the forged idler yoke P/N 28- 13223 for cracks.

(c) If cracks in the forged idler yoke P/N 28-13223 are detected when inspected in accordance with paragraph (a) or (b) above, replace it before further flight with a cast idler yoke P/N 28-13299, at which time the inspections required by this Airworthiness Directive are no longer applicable.

(d) The forged idler yoke P/N 28-13223 can be replaced at any time with a cast idler yoke P/N 28-13299 at which time inspections required by this Airworthiness Directive are no longer applicable.

(e) Equivalent methods of compliance with this Airworthiness Directive must be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Great Lakes Region.

Amendment 39-1856 was effective June 5, 1974, and was effective April 19, 1974, for all recipients of the air mail letter dated April 19, 1974, which contained this amendment.

This Amendment 39-1940 becomes effective September 4, 1974.

FOOTER: