A similar engine fault behind a fatal mid-air engine explosion that punctured a passenger jet window was reported in 2016, it has emerged.
A female passenger died after she was nearly sucked from the cabin of a Southwest Airlines flight travelling from New York to Dallas on Tuesday.
Investigators say there was a fault with the engine's fan blades - the cause of the incident two years ago, reports BBC.
US aviation authorities are to order inspections of similar jet engines.
Southwest Airlines Flight 1380, a Boeing 737 which was carrying 149 people, was forced to make an emergency landing at Philadelphia airport on Tuesday following a fault with one of its CFM56-7B engines.
An initial investigation found evidence of metal fatigue where a fan blade had broken off, according to the US National Transportation Safety Board (NTSB).
A similar incident was recorded in 2016 involving a Southwest flight that landed safely in Florida.
Fan blades that have undergone a certain number of flights will have to be given ultrasonic tests, the Federal Aviation Administration (FAA) has said.
It added that the "airworthiness directive", which will require inspections of a large number of CFM56-7B engines, would be issued within the next two weeks.
The CFM56-7B engine is in use on more than 8,000 Boeing 737 planes worldwide, the manufacturer says.
Last year, the FAA estimated that some 220 of these engines would require testing, having carried out a certain number of flights.
On Wednesday, other airlines that use planes fitted with the CFM56-7B engine, including United Airlines, American Airlines and Delta Air Lines, said they had begun inspecting some of their aircraft.
NTSB chairman Robert Sumwalt told reporters that a fan blade had broken off due to metal fatigue and that a second fracture had been recorded about halfway along its length.
He could not say if the incident indicated a fleet-wide issue with the Boeing 737-700.