AD/LJ45/7 Main Landing Gear Trunnion Shear Pins 11/2003
Applicability: Model 45 aircraft, serial numbers 45-005 through 45-208, 45-210 through 45-222, 45-224, 45-225, 45-227, and 45-229 through 45-231.
Note: FAA AD 2003-16-09 Amdt 39-13262 refers.

Compliance:
1. Within 14 days after 3 September 2003.
2. Before the accumulation of 1,800 total landings on the shear pins, or within 100
landings after 3 September 2003, whichever occurs later.
This Airworthiness Directive becomes effective on 3 September 2003.
Background: Results of fatigue testing conducted by the manufacturer on the main landing gears of Learjet 45 aircraft indicate that certain shear pins on the trunnion assemblies of the main landing gears do not meet the expected life limit. The results of fatigue testing also indicated that the shear pin bushings in the trunnion fitting housings had migrated outward from the fitting, which further weakened the shear pins and contributed to premature failure. This condition, if not corrected, could result in collapse of a main landing gear, and consequent reduced controllability of the aircraft during takeoff and landing.

FMI: www.casa.gov.au/avreg/aircraft/ad/ADfiles/Over/lj45/LJ45-007.pdf