The emergency airworthiness directive will require airlines to perform an ultrasonic inspection of certain CFM56-7B engines within 20 days of receipt of the order, it said. The blade was made of titanium from the TIMET plant in Henderson, according to the Federal Aviation Administration's report. There are now about 14,000 CFM56-7B engines in operation.
On Wednesday, National Transportation Safety Board (NTSB) Chairman Robert Sumwalt, the chief investigator of United States aviation accidents, said he could not yet say if the incident pointed to a fleet-wide issue.
Jennifer Riordan had two children. The jet, which was headed from NY to Dallas with 149 people aboard, made an emergency landing in Philadelphia.
Southwest did not answer BuzzFeed News' questions about the apology and payments, but said in an email that "the communication and gesture are authentic and heartfelt".
The directives from the US Federal Aviation Administration and the European Aviation Safety Agency indicated rising concerns since a similar failure in 2016 of the same type of engine - a CFM56-7B engine, made by CFM International.
"The unsafe condition", the FAA said in the inspection directive, "is likely to exist or develop in other products of the same design".
The guidelines from the manufacturer, CFM International, call for ultrasonic inspections - which can detect flaws or cracks not visible to the unaided human eye - within the next 20 days to fan blades on engines with more than 30,000 cycles. The engine that blew apart on Tuesday's Southwest flight would have been affected, since the company said it had 40,000 cycles.
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.
On Tuesday, Southwest Airlines flight 1380 from New York City to Dallas was flying at an altitude of over 31,000 feet with 144 passengers and five crew on board when a fan blade in the Boeing 737-700's left engine separated from the engine hub just 20 minutes after takeoff.
In the earlier case, a fan blade fractured and broke loose, bouncing in front of the engine's protective cover and then striking the plane, causing it to lose pressure. The plane made an emergency landing in Philadelphia.
The manufacturer told CNN it has been working with the FAA on the inspection procedures. The agency announced on Wednesday it would issue those orders within weeks.
The Federal Aviation Administration (FAA) has ordered the inspection of nearly 700 Boeing 737 engines across the globe over the next 20 days. More than 150 of those have already been checked, it said.