COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Enstrom F-28 Series Helicopters
AD/ENST 28/36 Lamiflex Bearings 12/94 TX
Applicability: Models F28A, C, C2, F; 280, 280C, F and FX with main rotor feathering elastomeric Lamiflex bearings P/N 28-14320-12 or 28-14320-15.
Requirement: 1. Action in accordance with Enstrom Service Directive Bulletin No. 0081 Rev. A.
2. Remove from service any Lamiflex bearing where the Date of Manufacture is:
- not visible or illegible, or
b. marked as being manufactured five years prior to any inspection carried out in accordance with this Directive.
Note: FAA AD 94-17-15 refers.
Compliance: Within five hours time in service after 26 September 1994. Thereafter at intervals not exceeding 100 hours time in service; and anytime the symptoms specified in paragraphs 4.1.1 to 4.1.4 of the Requirement Document are experienced.
Background: There have been reports of several failures of the subject bearings where the bearings have delaminated and extruded rubber and brass. Continued operation in this condition may result in complete delamination, resulting in failure of the bearing, and loss of control of the helicopter. This Directive also imposes a five year since manufacture calendar life on the bearings.