COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Robin Aviation Series Aeroplanes
AD/ROBIN/24 Empennage Attach Bolts 10/95 DM
Applicability: All models R2000 Series.
Requirement: 1. Verify by torque breakout check that the elevator (stabilator) bearing attach bolts on both the elevator and the fuselage, and the fin attach bolts are torqued to the figures specified below.
- Bolt 5mm dia. - torque...........(44 in.lbs)
b. Bolt 6mm dia. - torque..........(80 in.lbs)
c. Bolt 8mm dia. - torque..........(77 in.lbs)
2. Where a torque does not meet the figures above, or for other reasons cannot be verified:
- Remove the bolt and either:
(i) discard and replace with a new item, or
(ii) inspect for cracking using either the magnaflux or fluorescent dye techniques.
b. Inspect the backs of the bearing brackets and the mating areas of the fuselage and elevator for evidence of fretting and/or fretting corrosion.
3. Install the elevator bearing (fuselage) bolts with the bolt heads on the bearing side, not inside the fuselage.
4. Torque elevator and fin attach bolts to the values specified in Paragraph 1.
Compliance: At the next inspection for Maintenance Release issue after 14 August 1995, or at compliance with AD/ROBIN/21, whichever occurs first.
Thereafter for Paragraphs 3 and 4 only, at any time a fin or elevator bolt is removed and replaced.
Note: The above procedures are to remain in place until the current Maintenance Manual; i.e. R2000 Service Manual Issue 1 Revision 3, October 1979, is either revised or reissued, and the changed torque values and bolt installation are addressed.
Background: The Authority has via a Major Defect Report discovered that the torque values specified for the elevator in the Maintenance Manual are not correct, and that no torque value is specified therein for the Fin attach bolts. Insufficient torque may lead to fretting of the attached items and/or fatigue failure of the attaching bolts.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
It was also discovered that the IPC illustration describes one set of elevator bearing bolts as being installed from the inside of the fuselage. Installation in this manner may cause control interference.