COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Eurocopter AS 355 (Twin Ecureuil) Series Helicopters
AD/AS 355/26
Amdt 1
Tail Rotor Control Spider 8/87
Applicability: All model AS 355 helicopters fitted with tail rotor control spider P/Nos 350A33- 2004-00, 01 or 02 and P/Nos 350A33-2008 and 2009 all dash numbers.
Requirement: 1. (a) Remove the hub assembly, spider assembly and non rotating spider.
(b) Visually check for condition of the contact surface of the nut lockwasher, bushes and the bearing baffles and journals.
(c) If there is no evidence of rotation of outer and inner bearing races or metal fretting or pick up, reassemble control spider.
(d) If there is evidence of rotation of outer and inner bearing races, metal fretting or pick up, replace spider assembly.
2. The following procedure is to be carried out when fitting control spider assembly.
(a) Scrap and replace existing lock washer by a new lock washer.
(b) Tighten the nut to a 60 Nm torque. (530 inch lbs).
(c) Release the nut at least one quarter of a turn and retorque it to 40 to 60 Nm (355-530 inch lbs) in order to ensure safetying.
(d) Safety the nut with 0.8mm lockwire.
Note 1: If nut safetying is not possible within the range of 40 to 60 Nm (355-530 inch lbs) scrap the nut and replace it with a new nut.
Note 2: Aerospatiale Telex No 11185 dated 8 April 1987 and telex No 11538 dated
13 May 1987 refers.
Compliance: For Para 1: Unless already accomplished within 100 hours time in service after
31 July 1987.
For Para 2: At any time the tail rotor control spider assembly is installed.
Background: Several cases of loosening of the nut on the pitch control spider have been reported. This Directive has been amended to extend compliance to additional P/No spiders.