As Pilatus was celebrating the worldwide fleet of more than 500 Pratt & Whitney PT6A-67B-powered PC-12s surpassing one million flight hours, the engine manufacturer was working with the fuel control unit (FCU) supplier to obtain approval for an improved pneumatic system. P&WC expects to have an upgrade plan in place before the end of this month. In the recent past, PC-12s have been involved in six power roll- backs–four in flight and two on the ground–attributed to failure of the FCU. Two of the in-flight events–in July and December last year–ended in successful deadstick landings. About a month after the December incident, which the NTSB is still investigating, P&WC and Pilatus reissued safety and service information letters to PC-12 operators restating the proper operation of the manual override system designed to restore and control engine power.