The new AD, set for publication May 2 and effective May 12, orders operators to conduct ultrasonic or eddy current inspections on CFM56-7B fan blades before they reach 20,000 cycles. Blades with 20,000-30,000 cycles, or blades where the age is not known, must be inspected by Aug. 31, or within 113 days of the directive’s effective date. Blades with 30,000 or more cycles were the target of the April 20 AD.
The new directive also requires follow-up checks every 3,000 cycles—roughly two years of typical Boeing 737NG airline service. FAA said the AD covers about 3,700 engines.
Collected and summarized from the source below by Ta Ngoc Diep: