AD/LEARJET 35/39 - Forward Engine Beam Shear Web (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Gates Learjet 35 and 36 Series Aeroplanes

AD/LEARJET 35/39 Forward Engine Beam Shear Web 5/2004

Applicability: Model 35, 35A, 36, and 36A aircraft, with serial numbers listed in Bombardier Service Bulletins 35/36-51-3, and 35/36-51-4 Revision 1 or Revision 2.

Requirement: 1. Accomplish a detailed inspection (using a probe) and a general visual inspection of the shear webs of the forward engine beams (including modification of the drag angles) for cracking in accordance with the Accomplishment Instructions of Bombardier Service Bulletin (SB) 35/36-51-3, dated 1 February 2001.

2. Following detailed probe inspection required by Requirement 1, accomplish the follow-on actions specified in following Requirements 2.a., 2.b., or 2.c., as applicable, in accordance with Accomplishment Instructions of SB 35/36-51-3.

1. If the resistance measured during the inspection is less than 0.110 milliohm, repeat the inspections required by Requirement 1.

b. If the resistance measured during the inspection is 0.110 milliohm or more, but less than 0.150 milliohm, repair and modify the forward engine beam shear web in accordance with the Accomplishment Instructions of SB 35/36- 51-4 Revision 1, dated 2 August 2001, or Revision 2, dated 6 December 2001.