Compliance: 1. Installed MGB’s incorporating bevel gears which have logged more than 6,600 flight hours:

Within 50 flight hours from the effective date of this Directive, thereafter at intervals not to exceed 150 flight hours or 1000 torque application cycles for helicopters performing external load carrying missions, whichever occurs first, from the effective date of this Directive.

For MGB’s where the torque application cycles exceed 1000 cycles since the last borescope inspection was carried out; within 300 torque application cycles.