Engineers decided to use MCAS to counter that tendency, since major structural redesign would have been prohibitively expensive and time-consuming. Boeing's goal was to have the MAX certified as another 737 version, which would appeal to airlines with the reduced cost of pilot training. The Federal Aviation Administration (FAA) approved Boeing's request to remove a description of MCAS from the aircraft manual, leaving pilots unaware of the system when the airplane entered service in 2017.[2]