![Pratt & Whitney powered 777s grounded [Video]](https://WorldNews.360Wise.com/wp-content/uploads/2021/02/mp_155497_0_UnitedAirlines777jpg-1200x619.jpg)
Boeing has recommended that any airline flying the Pratt & Whitney 4000-112 powered Boeing 777 should ground them pending an investigation into the United Airlines flight which suffered an uncontained engine failure on Saturday.
Boeing 777
![Pratt & Whitney releases statement following engine explosion over Denver [Video]](https://WorldNews.360Wise.com/wp-content/uploads/2021/02/mp_155362_0_f0972a207fa74f129de5e625465a268c1jpg-1200x800.jpg)
Investigators are now searching for a key piece of evidence to determine what caused the engine to fail: a fan blade that broke in two. Experts said finding the other piece is critical.
![Japan Grounds All Boeing 777 Planes After Denver Engine Fire [Video]](https://WorldNews.360Wise.com/wp-content/uploads/2021/02/mp_154754_0_GettyImages1231291896jpg.jpg)
Japan has ordered its domestic airlines to ground all Boeing 777s, in response to an incident Saturday where a plane engine caught fire shortly after takeoff.
![United Airlines engine failure: US orders inspection of some Boeing 777s jets; Japan suspends use [Video]](https://WorldNews.360Wise.com/wp-content/uploads/2021/02/mp_154676_0_20210222T001703Z523322349RC2CXL96XVW7RTRMADP3BOEING777JAPANjpg.jpg)
The regulatory moves involving Pratt & Whitney 4000 engines came after a United Airlines 777 landed safely at Denver International Airport on Saturday after its right engine failed.