With the termination of the Boeing 747 and Airbus A380 programs, the Boeing 777 is currently the largest aircraft in production. The modernized Boeing 777X is set to compete with the Airbus A350.

Pratt & Whitney (P&W) and Boeing are asking the Federal Aviation Administration for more time and for regulatory exemptions as part of design changes they are making to PW4000-112 turbofans and the ...