Ultra Electronics of the UK is developing its UltraQuiet Active Noise Control System for the Raytheon Beech 1900D. The system is being developed jointly with Elliott Aviation of Moline, Illinois, Ultra's US distributor of the systems to the corporate turboprop market and also with the support of Raytheon.

The first 19-seater Beech aircraft to feature this new system is scheduled for delivery in July. UltraQuiet cabins can also be retrofitted and are available to 1900D operators currently in the market.

The UltraQuiet system is based on the King Air 350 system. It can also be found on the Saab 2000 and the Saab 340B-plus. The 1900D system comprises 20 loudspeakers, 40 microphones and a high speed digital processor.

The system acoustically cancels the propeller tones in the cabin by introducing sound waves that are of equal frequency and amplitude, but are of opposite phase to the unwanted noise.

Mike Scheidt, vice president of airline programs at Raytheon, said he expects the UltraQuiet cabin option will aid the success of the 1900D by further improving passenger comfort.

The UltraQuiet Active Noise and Vibration Control system, which uses active tuned vibration attenuators instead of loudspeakers, is fitted as standard to all of the aircraft in Bombardier's Q Series, including the Q100, Q200, Q300 and Q400 regional turboprops.