COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Schweizer (Hughes) 269 Series Helicopters
AD/HU 269/102
Amdt 1
Applicability: All models
Cyclic Control Column 1/95 DM
Requirement: 1. Inspect and check for the following:
- At the wiring loom hole and the adjacent area of the tube just above the pivot fitting inspect for:
(i) cracking in the lower 50mm of the tube above the pivot fitting and around the hole, using 10X magnification or better;
(ii) any rework, scores, nicks or file marks,
(iii) any buckling or crippling or the tube 50mm either side of the hole, using a straight edge and feeler gauges, and
(iv) hole size and location - 12.5mm dia. (1/2"), and 19mm (3/4") above the top surface of the stick assembly socket; and
b. Check that the breakout forces for the cyclic control column are within the tolerances specified by the manufacturer.
2. Remove from service any cyclic control column that does not pass the inspection criteria at Paragraph 1.a.
3. In accordance with a scheme acceptable to the Authority, reinforce the control column tube locally in the region of the electrical loom hole, to increase the bending strength of the column.
Compliance: 1. Within 25 hours time in service after 30 November 1994.
2. Prior to further flight after inspection.
3. Within 100 hours time in service after 23 November 1994 or before 28 February 1995 whichever occurs first.
Background: The initial issue of this Directive was raised in response to a crash resulting from a cyclic control column failure in flight and loss of control; where the failure was initially attributed to fatigue. The final BASI report indicates, through a finite element analysis, that the control column static strength is marginal with relation to the Certification basis of the helicopter.