LORD, THE Pennsylvania-based noise-control specialists has confirmed major contracts received from Cessna for its Citation X, and from Stevens Aviation, which will act as US distributor for its NVX active noise system, on the Raytheon Beech King Air 200 and 300.
Lord has worked with Cessna for some time to develop a hybrid noise-control system for the Citation X, and recently announced a contract for 106 shipsets of its active isolation-control equipment.
The system introduces electro-mechanical actuators between the engine mounts and the airframe, helping to cut noise introduced into the fuselage through vibration. At the same time, some of the vibration will be absorbed through the company's more traditional passive dampers. Lord says that the reduced vibration in the airframe will help cut the Citation X's interior noise level by up to 86%.
The second major contract is from Stevens Aviation, a multi-site US fixed-base operator with its headquarters in Arkansas. Stevens was granted a supplemental type certificate for the NVX modification on the King Air 200/300 series in the middle of September.
NVX cuts cabin noise by recording and analysing noise before outputting an equal and opposite noise through speakers mounted throughout the cabin.
During flight tests on King Air 200s, the NVX system has produced interior-noise reductions of up to 70% (10dB) and noise at blade passage frequencies (by the plane of the propeller) by as much as 90% (20dB).
Source: Flight International
