Boeing Grounds 777’s After Investigation Into Exploding Engine Shows Blade Damage

United Airlines - N813UA - Airbus A319 - San Francisco International Airport

The National Transportation Safety Board provided an update on its investigation into United Airlines flight 328.

The Boeing 777 was heading from Denver to Honolulu with about 230 passengers and 10 crew aboard on Saturday when its right engine failed and erupted in flames. The plane quickly lost altitude and dropped huge pieces of the engine casing and chunks of fiberglass onto the neighborhoods below. The plane returned to Denver with minor damage and landed safely. Authorities said no injuries were reported aboard the plane or on the ground where debris fell.

Several NTSB officials from the Denver regional office began the investigation, while the investigator-in-charge for the event traveled from Washington Sunday morning.

The probe is ongoing, with the NTSB working alongside the Federal Aviation Administration, United Airlines, Boeing, Pratt & Whitney, the Air Line Pilots Association and the Independent Brotherhood of Teamsters.

In a Sunday evening update the NTSB said that an initial examination indicated that the airplane sustained minor damage, most of which was “confined to the number 2 engine.”

Investigators noted that the inlet, a duct which is required to ensure smooth airflow into the PW4000 engine, and a cowling, the removable metal covering that houses the engine, were separated from the engine. In addition, two fan blades were fractured while the remainder of the blades exhibited damage to their tips and leading edges.

The team also plans to examine the plane itself, photos and videos captured by passengers aboard the flight, the cockpit voice recorder and flight data, which have all been transported to Washington for analysis.

Boeing has grounded the 777s equipped with PW4000 engines while the investigation continues.