Business aircraft cabins are generally not quiet. Not with the turbulent boundary-layer rush of air around the fuselage at Mach 0.85 and the whine of a couple of jet engines no great distance from the comfy chairs. Then there are the pumps, hydraulics, fans, gears, actuators, electric motors, worn bearings and air distribution through the metal ductwork, not to mention the occasional hum of the microwave and induction oven, the rattling of glasses and flatware in the galley and that giant sucking sound coming from the lavatory.
Aerocon Engineering has signed a contract with an undisclosed customer to design a cabin noise-reduction system for a head-of-state 747-8i.
According to CEO Benny Younesi, the Van Nuys, Calif.-based company’s latest system upgrade will be “lighter, more efficient, more cost effective and easier to maintain.” The company intends to seek STC approval from both EASA and the FAA.
Alto Aviation, a supplier of business jet cabin audio systems, is urging completion and refurbishment centers to rethink speaker grille construction.
“It is one of the most common problems we encounter,” according to the Leominster, Mass.-based company. “Sound waves are made up of the compression and expansion of air [and] if air can’t move through the speaker grille, then the sound can’t get into the cabin.”
Alto recommends speaker coverings that are at least 50-percent open to ensure the best audio performance.
The FAA issued a proposed rule on Tuesday that is aimed at reducing noise generated by new helicopters certified under Part 36 (noise standards) of the FARs. If adopted, the rule would impose standards already adopted by ICAO.
A new noise-cancelling headset introduced in April at the Aircraft Interiors Expo in Hamburg, Germany, is set to find a market in business and private aviation.
Middletown, R.I.-based Avid claims the headset “effectively reduces environmental external noise by 85 percent with a 20-decibel maximum noise attenuation.” Forty-millimeter speakers, said an Avid spokeswoman, “ensure crisp, clear sound and well defined bass.”
Smac Aero of Toulon, France, continues to develop new technology aimed at reducing aircraft cabin noise and promoted its full line of noise-reduction technology in Cannes, France.
Among the latest items is the SmacBarrier, an acoustic layer designed to reduce the transmission of sound generated around window trim panels, flooring and ceiling panels.
Also fresh off the development line is SmacFoam, specifically created to reduce sound transmission and provide sound absorption in smaller, confined spaces.
Thermal/acoustic specialist 3M introduced a new acoustic demonstrator from its subsidiary E-A-R Thermal Acoustic Systems (Booth No. N5930) here at the NBAA convention. The demonstrator was created to simulate not only interior noise levels of a typical business aircraft, but also the range of noise signatures with varying frequency content.
Silentium Air introduced its 300 series, a customized noise-reduction kit developed expressly for the Bombardier Challenger 300.
A new thermal/acoustic barrier package promises to reduce cabin noise by as much as 30 percent. The Silentium Air SPS 360 is a product of Aviation International Management Services (AIMS) of Montreal, which is supplying the kits to exclusive marketing agent Zenith Jet, also of Montreal.
Enstrom 480, Goshen, Ind., Aug. 5, 2005–The NTSB determined the landing accident was caused by “ground resonance experienced by the pilots.” The student pilot/owner was flying the turbine helicopter, accompanied by a 2,107-hour CFI, when it experienced ground resonance and disintegrated. The helicopter’s tail was sheared from the body and landed 30 feet away, the front seats about 10 feet away.
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