(Adds Trump meeting with crew, passengers statement)
By David Shepardson
WASHINGTON, May 1 (Reuters) - The U.S. Federal Aviation Administration said on Tuesday it has ordered additional inspections of fan blades in hundreds of additional engines similar to the one that failed in a deadly Southwest Airlines Co accident last month.
The new FAA rules come after an emergency directive issued last month by the agency and European regulators requiring 680 CFM56-7B engines worldwide be inspected within 20 days on Boeing 737 NG airplanes.
Another group of CFM56-7B engines will need to be inspected by August under the regulation, the FAA said, adding that it is requiring repeat inspections of engines as part of Tuesday's action.
The April 17 engine explosion on Southwest Airlines flight 1380 was caused by a fan blade that broke off, the FAA said. The blast shattered a window, killing a passenger who was partially sucked out of the plane window in the first U.S. passenger airline fatality since 2009.
The FAA said an "unsafe condition exists that requires the immediate adoption" of the rule without a chance for public comment. In a notice posted in the Federal Register, the agency said "the risk to the flying public justifies" the quick adoption of the rule.
CFM, jointly owned by General Electric Co and France’s Safran, produces the CFM56 engine in factories in the United States and Europe.
The emergency action last month by the FAA and the European Aviation Safety Agency required ultrasonic inspections on fan blades that have been used in more than 30,000 cycles - or in service for about 20 years - within 20 days. A cycle includes one take-off and landing.
The FAA announcement on Tuesday requires inspections by August of CFM engines with 20,000 cycles of use, and then regular inspections for fan blades every additional 3,000 cycles, or about every two years. European regulators on April 20 adopted the actions taken by the FAA on Tuesday.
U.S. President Donald Trump met Tuesday with some passengers and the flight crew of Southwest Flight 1380 at the White House, praising their efforts. "The actions of the crew and passengers of Southwest Flight 1380 show the great character of our nation," Trump said.
The National Transportation Safety Board (NTSB) is investigating the events that led to the first passenger death in Southwest's history.
In a conference call last week with analysts and reporters, Southwest Chief Operating Officer Michael Van de Ven described the extensive damage to the plane's engine and cowling - the smooth metal exterior that covers the engine's inner workings.
"The loss of a single blade inside the engine just shouldn't have caused such dramatic impact," Van de Ven said.
Metal fatigue, the degradation of a metal's structural integrity over repeated use, likely caused the fan blade to break apart, according to the NTSB.
Southwest spokeswoman Brandy King said the airline planned to complete ultrasonic inspections on all fan blades on the some 700 planes in its fleet with the CFM56-7B engines over the next two weeks, meeting the FAA's August deadline by mid-May.
King said Southwest has not found any cracks on fan blades inspected since the accident. (Reporting by David Shepardson; additional reporting by Alana Wise Editing by Bill Trott and Dan Grebler)