WASHINGTON, Feb. 23 (Xinhua) -- The U.S. Federal Aviation Administration (FAA) issued an emergency airworthiness directive Tuesday night that requires U.S. operators of airplanes equipped with Pratt & Whitney PW 4000 engines to inspect these engines before further flight.
"The FAA is taking this action as the result of a fan-blade failure that occurred Saturday on a Boeing 777-200 that had just departed from Denver International Airport," said the agency in a statement.
Although the aircraft landed safely, the failure resulted in damage to the engine, an in-flight engine fire, and damage to the airplane.
No injuries were reported on the flight which had 231 passengers and 10 crew members onboard.
After reviewing the available data and considering other safety factors, the FAA determined that operators must conduct a thermal acoustic image (TAI) inspection of the large titanium fan blades located at the front of each engine.
TAI technology can detect cracks on the interior surfaces of the hollow fan blades, or in areas that cannot be seen during a visual inspection, according to the FAA.
As these required inspections proceed, the FAA will review the results on a rolling basis, said the statement.
"Based on the initial results as we receive them, as well as other data gained from the ongoing investigation, the FAA may revise this directive to set a new interval for this inspection or subsequent ones," said the statement.
The previous inspection interval for this engine was 6,500 flight cycles. A flight cycle is defined as one takeoff and landing.
After the incident occurred, Boeing recommended suspending operations for over 100 of its 777 models powered by Pratt & Whitney 4000-112 engines -- 69 of them in use and another 59 in storage -- effective until "the FAA identifies the appropriate inspection protocol" for the aircraft.
During a virtual town hall about commercial aviation safety on Tuesday, FAA chief Steve Dickson warned of vast changes in the aviation industry in the wake of the COVID-19 pandemic, ones that will make addressing new safety risks a pressing need.
"The industry that existed last March in many respects no longer exists today," Dickson said, citing the retirement of veteran pilots, new fleets with complex aircraft and less international flying.
"All these changes are creating a whole new set of stressors that can inject new safety risks into the system," he added. Enditem
