A jet aircraft has a mass of 5800kg and a wing area of 21.5m. It is flying at a speed of 240m/s at an altitude where =0.84. The throttle lever is suddenly moved to the flight idle position, after which it may be assumed that the engines deliver zero net thrust. Determine the time taken for the speed to fall to 160m/s while maintaining level flight. The drag coefficient is given by CD = 0.0276 0.075CL