Regulators Considered Extra Scrutiny Of Airplane Engine Before It Caught Fire Mid-Flight And Dropped Parts Over Colorado

Regulators had already considered mandating additional scrutiny on some Pratt & Whitney engines before one on a Boeing 777-200 fell apart mid-flight over the weekend.

The preliminary investigation into the Hawaii-bound United Airlines flight, which conducted an emergency landing in Denver on Saturday, showed there was metal fatigue on one of the engine’s 22 fan blades, National Transportation Safety Board (NTSB) investigators said late Monday night. The weakened blade is thought to have then interfered with and sliced a second blade.

“A preliminary on-scene exam indicates damage consistent with metal fatigue,” NTSB Chairman Robert Sumwalt said.

Sumwalt added that Pratt & Whitney will examine the recovered blade at its factory on Tuesday alongside NTSB investigators. The safety agency’s ongoing investigation involves an examination of the engine, videos taken by passengers aboard and fallen debris in Broomfield, Colorado, the agency said in a statement Sunday.

The same Pratt & Whitney engine has been involved in previous incidents, which caused investigators to consider mandating strict inspections, according to The Wall Street Journal. A United flight in 2018 and a Japan Airlines flight to Tokyo in December had issues with the same Pratt & Whitney engine.

Japan’s transportation agency determined the December incident was caused by engine blade damage, according to the Japan Times. On Sunday, Japan ordered all Boeing 777-200 planes using the Pratt & Whitney engine grounded pending further inspection.

“We recommended suspending operations of the 69 in-service and 59 in-storage 777s powered by Pratt & Whitney 4000-112 engines until the [Federal Aviation Administration] identifies the appropriate inspection protocol,” Boeing said in a statement Sunday.