The European Aviation Safety Agency is reportedly adopting similar requirements. The FAA is expected to follow CFM's lead and set the same conditions.
Moments after the 737's engine exploded, Southwest passengers rushed to help those injured. The NTSB said a fan blade separated from the fan disk and showed evidence consistent with fatigue crack growth.
On Tuesday, Gary Kelly released a video message reacting to the death of Jennifer Riordan (who wasn't identified at the time in the video).
The Southwest Boeing 737 took off Tuesday morning from NY, headed for Dallas.
The airline has sent passengers apology letters and cheques for US$5,000 "to cover any of [their] immediate financial needs".
If a discrepancy is detected on an affected fan blade, it must be replaced before flying again, the EASA directive states.
"The aircraft is now parked in Acrra and our team of engineers are conducting comprehensive inspections on the aircraft to ascertain the cause of the smoke, after which the aircraft will be flown without passengers to a maintenance facility for rectification and testing", Arik had said at the time.
"Engines with more than 30,000 total cycles from new must complete inspections within 20 days", the FAA said in a statement Friday.
The CFM56 arguably the most popular jet engines in the world with more than 30,000 units produced since 1980 and is used on both civilian and military aircraft.
The incident raised a number of questions because jet engines are certified to be able to withstand a broken fan blade without causing major damage.
Passenger Marty Martinez shared photographs and videos of himself on Facebook as the plane made its descent.
"The public should be anxious (because) a manufacturer sent out a warning, and Southwest and others didn't do it", said Mary Schiavo, a former inspector general of the Transportation Department, FAA's parent agency. The agency never issued a final decision, however.
A spokesman for CFM told Gizmodo that the engine involved in Tuesday's incident was not subject to the Service Bulletins issued following the 2016 incident, and that Southwest had implemented the recommended inspections.
More than 150 have already been inspected.
The Federal Aviation Administration (FAA) has ordered the inspection of nearly 700 Boeing 737 engines across the globe over the next 20 days.
On Tuesday, fan blade snapped in a Boeing 737 operated by Southwest Airlines.