Summary
We propose to adopt a new airworthiness directive (AD) for all Fokker Services B.V. Model F28 Mark 0070 and 0100 airplanes. This proposed AD was prompted by an aileron-wing flutter analysis finding that when a hydraulic aileron actuator is not powered, while at least one aileron flutter damper is inoperative (latent failure), the maximum speed currently defined in the airplane flight manual (AFM) is insufficient to meet the required safety margin. This proposed AD would require revising the AFM to include procedures to follow in the event of a hydraulic system failure and abnormal flight control behavior. We are proposing this AD to ensure that the flightcrew has procedures to follow in the event of a hydraulic system failure and abnormal flight control behavior. If not corrected, this condition could lead to aileron flutter and possible reduced control of the airplane.