Hush Kit Reduces Cabin Noise in Premier I
Raytheon Aircraft announced a lightweight interior modification for its Premier I that the company says reduces cabin average noise level to 82.2 dBA on takeoff and 73.6 dBA during long-range cruise. (Normal conversation in a quiet room is conducted at about 60 to 70 dBA.) In 2002 Raytheon identified sound sources and frequencies and decided to install hydraulic pulse dampeners and tuned mass absorbers on the engine mounts and increased the engine/pylon skin gap. Now the company is adding a three-pound acoustic liner between the fuselage and interior. It will be standard, starting with S/N RB-112, and the company is developing a kit as a retrofit item for existing aircraft.