Boeing had been working to strengthen engine covers on the 777 for about two years

 New York, Feb 25 (AFP/APP): Boeing had been working to strengthen engine covers on the 777 for about two years before last weekend’s scare on a United Airlines flight, according to a report Thursday.

Boeing was working with the Federal Aviation Administration to strengthen protective engine covers following similar problems on earlier flights preceding Saturday‘s emergency landing, the Wall Street Journal reported. The report comes amid a National Transportation Safety Board investigation of Saturday‘s United flight, which returned to Denver soon after disembarking after the engine caught fire and began breaking apart. No one was hurt in the incident, but the episode raised questions about maintenance on the jets.

On Tuesday night, the FAA ordered inspections of all Pratt & Whitney engines similar to the one that broke apart. Investigators have attributed the Denver incident to a fan blade that broke off soon after takeoff due to metal fatigue and apparently breached the engine cover, known as a cowling. Both Boeing and the FAA avoided discussing specifics on the efforts to modify the 777. Such changes typically require signficant evaluation and testing. Boeing is “in constant communication with our customers and the FAA, and engaged in ongoing efforts to introduce safety and performance improvements across the fleet,” a Boeing spokesman said.