COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
DHC-2 (Beaver) Series Aeroplanes
AD/DHC-2/30
Amdt 1
Front Fuselage Struts at Windshield 13/99
Applicability: All model DHC-2 Mk. I and Mk. II “Beaver” and DHC-2 Mk. III “Turbo Beaver” aircraft.
Requirement: Accomplish either Requirement 1 or Requirement 2 below:
1. Replace installed front fuselage struts with replacement part number struts listed in the accompanying Table:
Installed P/N | Replacement P/N | Description |
C2FS209 or C2FS3281A | C2FS3281A | Strut Assembly Front Fuselage, Left |
C2FS210 or C2FS3282A | C2FS3282A | Strut Assembly Front Fuselage, Right |
Once replaced in accordance with the above requirement, struts have a life limit of 15 years from the date of installation in accordance with PSM 1-2-2, Part 5, Temporary Revision 2-22, and PSM 1-2T-2, Part 5, Temporary Revision 2T-6, both dated
3 August 1998.
2.a. Perform a detailed visual inspection of the front fuselage struts and all fittings attached to the frame for damage (corrosion, cracks, dents) using an inspection light, inspection mirror, and a 10x magnifying glass. On completion of the inspection, clean the drain holes around the bottom end fitting and protect the tube internally with an appropriate corrosion preventative spray (LPS #3 or equivalent recommended)
2.b. Perform an ultrasonic thickness measurement of all surfaces on the front fuselage struts. Although the inspection procedure detailed in Bombardier Service Bulletin 2/49 Revision C does not include inspection of the front fuselage struts, a procedure which follows a similar calibration procedure and measures strut thickness on all four surfaces at 25mm (1-inch) intervals is acceptable. There is a 100mm (4-inch) surface on the outboard side of each strut which is not accessible.
Replace any struts found below minimum thickness of 0.762mm (0.030 inch) before further flight; in accordance with Requirement 1 of this Directive.
Note 1: The 15 year life limit does not apply for struts inspected in accordance with Requirement 2 of this Directive.
Note 2: Transport Canada AD CF-98-37 R1 refers.
Compliance: 1. Before 30 April 2000, unless previously accomplished since 30 April 1985.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
The compliance of Requirement 1 of this Directive remains unchanged for this issue.
2.a. Initially, within 12 months after 30 December 1999, unless previously accomplished, and thereafter at intervals not to exceed 12 months.
2.b. Initially, within 24 months after 30 December 1999, unless previously accomplished, and thereafter at intervals not to exceed 5 years.
This Amendment becomes effective on 30 December 1999.
Background: Operators have reported numerous incidents of corrosion of the DHC-2 front fuselage struts on either side of the flight compartment windshield. These are structurally significant parts of the aircraft and inspection for corrosion is both difficult and work intensive. Bombardier/ de Havilland has published new life limits in the Recommended Overhaul or Replacement Schedule PSM 1-2-2, and PSM 1-2T-2.
Amendment 1 is issued in response to a revision of the related Transport Canada AD which introduces detailed visual and ultrasonic repetitive inspections as an alternative to the front fuselage strut 15 year life limit.
The original issue of this Airworthiness Directive became effective on 31 December 1998.