Boeing drops after airlines ground 777 planes following engine failure over Denver

• Boeing stock fell 3% during on Monday in the wake of the engine failure of a 777 plane over Colorado on Saturday.
• Boeing recommended airlines suspend the use of planes equipped with Pratt & Whitney PW44000-112 engines.
• The National Transportation Safety Board found two fan blades in the United Airlines engine were fractured.

Boeing stock dropped 3% Monday after the aircraft manufacturer recommended that airlines ground certain 777 planes after an engine failure on United Airlines flight rained debris over the Denver area on Saturday.

United Airlines said it will "voluntarily & temporarily" remove 24 Boeing 777 aircraft powered by Pratt & Whitney 4000 series engines from its schedule. The move came after Flight UA328 from Denver to Honolulu experienced an engine failure shortly after departure. The flight landed safely at Denver International Airport.

None of the 229 passengers or 10 crew members were injured, the National Transportation Safety Board said in a statement. Parts from the plane were found scattered around the Broomfield area, which is located about 22 miles east of Denver International Airport. The NTSB said Sunday an initial examination of the Pratt & Whitney PW4077 engine showed, among other findings, that two fan blades were fractured.

Boeing stock fell as much as 3.1% to $210.83 before trimming the loss to 1.8%. Boeing's shares over the past 12 months have lost roughly 33%. United shares, meanwhile, rose 3.5%.

"While the NTSB investigation is ongoing, we recommended suspending operations of the 69 in-service and 59 in-storage 777s powered by Pratt & Whitney 4000-112 engines until the FAA identifies the appropriate inspection protocol," said Boeing in a statement Sunday, referring to the Federal Aviation Administration.

Pratt & Whitney is a subsidiary of Raytheon Technologies. Raytheon stock fell 1.5%.

Boeing said it supported the decision by the Japan Civil Aviation Bureau and the FAA to suspend operations of 777 aircraft equipped with Pratt & Whitney 4000-112 engines.

"We are working with these regulators as they take actions while these planes are on the ground and further inspections are conducted by Pratt & Whitney," Boeing said.

The UK Civil Aviation Authority said Monday it has suspended the use of planes with Pratt & Whitney 4000-112 engines in UK airspace. The engines are not used by any UK airlines, it said.