Keeping cabins quiet

Citation

(2002), "Keeping cabins quiet", Aircraft Engineering and Aerospace Technology, Vol. 74 No. 5. https://doi.org/10.1108/aeat.2002.12774ead.010

Keeping cabins quiet

Keywords: Aircraft, Noise Levels, Environment

Industrial applications in interconnection technology are wide and varied. To incorporate its Active Noise and Vibration Control (ANVC) technology into commuter aircraft, Ultra Electronics needed a lightweight, compact, circular connector and Deutsch Ltd's industrial division's IMC connector was thought ideal for the task (Plate 8).

The dominant noise that passengers hear in an aircraft cabin results from vibrations being induced in the airframe by the engine or rotation of the propeller. Ultra Electronics is a major company in the application of ANVC technology for aircraft cabin quieting. ANVC is the reduction of noise and vibration by the introduction of additional noise and vibration to cancel the original. In the case of regional turboprop aircraft Ultra's UltraQuiet cabin is said to cancel the propeller tones, creating an environment that is quieter than a modern regional jet.

Plate 8 Deutsch's IMC connector helps Ultra keep cabins quiet

Ultra's ANVC system uses a central computer to drive Active Tuned Vibration Attenuators (ATVAS) mounted to the fuselage in opposition to the propeller and engine induced vibrations in the aircraft structure. The result is reported to be the dynamic freezing of the aircraft's fuselage, thus cancelling the source of the noise.

Working with Bombardier Aerospace, Ultra's system is said to have revolutionised the cabin of the Dash-8 regional turboprop to the extent that the aircraft has been rebranded the Q Series representing "quiet".

The Bombardier Q400, an 84-seat regional turboprop, has just entered service with Scandinavian Airlines System (SAS). The ANVC system on this aircraft comprises 80 ATVAs each with a dedicated power amplifier. Interconnections are made with the Deutsch circular Industrial Micro Connector (IMC). "The Deutsch IMC connector", says Laurence Earl, Ultra's marketing manager, "was selected by us on the basis of cost-effectiveness, ease of assembly and sealing ability".

The IMC 5 and 7-way connector being used is made from high temperature resistant, UL approved composite material and meets or exceeds UL94 Class V-0 flammability requirements. Sealed to IP67, the connector claims a current rating up to 13A, voltage rating from 750 to 1,000Vac (rms) and insulation resistance of 1,000M. The result is described as a rugged and chemical resistant electrical connector which enables it to withstand the rigours of industrial environments where heat, dust, moisture and chemicals are prevalent.

For the Q400 installation, Ultra worked with Deutsch to design a bespoke connector boot that complied with the stringent airworthiness flame retardant requirements. "System reliability is paramount to us", says Laurence Earl, "and with the Deutch IMC we have a connector solution that is robust and incorporates lightweight qualities that are essential in the aerospace industry".

Details available from: Deutsch Ltd. Tel: +44 (0) 142 485 2722; Fax. +44 (0) 142 485 1532; E-mail: k.winter@deutsch.co.uk; Web site: www.deutschltd.com