Winglet Lenses crack prevention

Effectivity: Challenger 300 and Challenger 350 aircraft

ATA 57

Bombardier Technical Services would like to reiterate the importance of following the correct torque sequences and torque values when installing the Winglet Lenses. Although it seems to be a simple task, not respecting the three torque sequences and values outlined in the AMM task 57-33-01-400-801 Installation of the Winglet Lenses − Wing Tip (541AT/641AT) will result in cracks around the screw holes. Please note that the Challenger 300 and Challenger 350 sequences are different. Following closely the AMM instructions will prevent lenses failure and associated unscheduled down time.  

Challenger 300 Torque sequence

Challenger 350 Torque sequence