• The fan blade failure is not a new issue - the key will be to determine the reason(s) for the recurring failure
• Is this an aging blade issue
• Is there an effective inspection process, especially if the failure is due to internal cracking
• Why did the fire in the rear section of the engine continue to burn even after the likely discharge of the suppression system by the crew.
• It appears the fire suppression system requirements need to be examined.

Mr. Feith and Mr. Goglia, world-renowned crash investigators host a weekly podcast on a wide range of airline safety issues. The US regulator, the FAA, has issued an emergency airworthiness directive (AD) requiring immediate or stepped-up inspections for P&W-powered 777s.

FAA Administrator Steve Dickson said: “Based on the initial information, we concluded that the inspection interval should be stepped up for the hollow fan blades that are unique to this model of engine, used solely on Boeing 777 airplanes.”

United Airlines said in a tweet: “We are voluntarily & temporarily removing 24 Boeing 777 aircraft powered by Pratt & Whitney 4000 series engines from our schedule. We will continue to work closely with regulators to determine any additional steps and expect only a small number of customers to be inconvenienced.”