Last June, engine manufacturer CFM International, a joint venture of General Electric Co. and France's Safran SA, recommended that airlines conduct the inspections of fan blades on many Boeing 737s.
United States and European aviation officials have ordered expedited inspections for airplane engines similar to the one that failed on a Southwest Airlines flight earlier this week that left one woman dead.
The directive, issued Friday, orders airlines to inspect all CFM engines with more than 30,000 cycles.
Once the inspections are completed, CFM recommended to repeat the process every 3,000 cycles - about two years in airline service - but the FAA did not require such a measure. The statement also say that the cancellations will only make up about one percent of Southwest's almost 4,000 flights Sunday.
The service bulletin called for ultrasonic inspections within the next 20 days on fan blades of engines which have accumulated more than 30,000 cycles.More news: Smallville star accused of recruiting women for sex with self-help guru
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The cancellations accounted for 1% of the Dallas-based airline's 4,000 flights scheduled, and wasn't part of a Federal Aviation Administration directive late last week, according to Southwest.
The 43-year-old mother of two was sucked out of the broken window and pulled back inside by fellow passengers.
The affected Southwest Boeing 737 took off Tuesday morning from NY, headed for Dallas. The FAA defines a cycle as one take off and one landing.
Southwest hasn't indicated how many CFM56-7B engines are in its fleet. The plane made an emergency landing at Philadelphia International Airport.
"We value you as our customer and hope you will allow us another opportunity to restore your confidence in Southwest as the airline you can count on for your travel needs". "Our Technical Operations Team is working safely and diligently to accomplish the inspections as soon as possible, including during the overnight period", Southwest says. National Transportation Safety Board investigators have said the fan blade that broke showed signs of metal fatigue, including microscopic cracks.