NVX Active Noise Control Systems for the King Air Series of Aircraft

Operators and passengers of King Air's can enjoy a quieter, more comfortable flight. With NVX Active Noise Control Systems on board, you'll find it easier to carry on conversations or conduct in-flight meetings. You'll hear how good your entertainment system really sounds. You'll discover a quieter, calmer atmosphere in which to work or relax.

NVX Active Noise Control Systems for the King Air use microphones to detect the noise in an aircraft interior and computer controlled speakers to generate an equal yet opposing sound pressure field in response. The two noise fields mix and counteract each other, effectively eliminating propeller induced disturbances to passengers and crew. Unlike traditional control methods, NVX Active Systems sense changes caused by varying flight conditions and automatically compensate to provide an unparalleled level of noise control.

The flexibility of the systems makes them adaptable to new interior configurations within a matter of minutes. They require a minimal number of microphones and speakers, and many of the components can be placed discreetly out of sight. Installation of an NVX Active Noise Control System can be accomplished in less than a week.

Performance Data

During a series of flight tests on a King Air 350, the NVX™ Active Noise Control System reduced the average interior noise level of the cockpit and passenger cabin to 82.3 dBA during cruise. The average passenger cabin noise level was reduced to 81.8 dBA.

Not only did the NVX system reduce the overall noise level during cruise, it significantly reduced noise during climb. Sound pressure level measurements taken between 5,000 and 15,000 foot altitudes during max torque climbs at 180 KIAS indicated that the NVX Active Noise Control System reduced the average cockpit and passenger cabin noise level to 81.9 dBA. The average passenger cabin noise level was reduced to 80.8 dBA.

NVX Active Noise Control nearly eliminates propeller noise from the cabin. The result is an environment more like what you'd expect to find in jet aircraft. During flight testing, NVX Active Noise Control Systems reduced overall noise levels by as much as 70% (10 dBC) and noise at blade passage frequencies by as much as 90% (20 dB). Retrofitting these systems on the King Air strengthens the aircraft's reputation as the most successful turboprop ever designed for the general aviation industry.

Hear the Difference

Check out the enclosed sound samples of the NVX system operating during an actual flight on a King Air 300.

WAV File (NVX Off = Loud) (NVX On = Quiet)

Please use a high fidelity speaker or headset as the affected frequencies are in the 50-300 Hz range.

Summary of Benefits

Small and lightweight in design, Lord NVX Systems offer a variety of customer benefits, including:

Improved crew/passenger comfort,
Less crew/passenger fatigue,
Improved passenger and/or crew communications ,
Reduced propeller beating.

King Air NVX System Components

Components	Quantity
Computer	1
Speakers	6-8
Reference Sensors	2
Microphones	16
Weight	45-55 lbs
Input Power	28 volts, 150 watts
Certification	STC & PMA

System Reliability

The NVX Active Noise Control System is designed to use the minimum number of components to achieve the optimal noise reduction performance. Matured, off-the-shelf components are used wherever possible.

The estimated total system reliability exceeds 5,000 hours Mean Time Between Failure (MTBF).

Overall Maintenance Philosophy

The maintenance strategy for the NVX Active Noise Control System is based on an "On-Condition" maintenance philosophy. No scheduled maintenance is required. The NVX System contains a Built -In-Test (BIT) capability that continuously monitors the health of the system. Should the BIT identify a critical failure, an indicator light will illuminate on the NVX control panel.

If further system diagnostics be required, the NVX System may be interrogated with any Windows 486 or later PC running the Lord diagnostic software. The diagnostic algorithms isolate faults to the Line Replaceable Unit (LRU), including; the computer, speakers, microphones, and accelerometers. Once installed, these LRUs may be easily removed and replaced without disrupting the aircraft interior.

Only standard A&P skills are required to perform line maintenance on the NVX Active Noise Control System. Typical maintenance actions may require the ability to check for continuity & shorts, inspect mechanical interfaces (brackets/connectors), and remove and replace LRUs/Fuses.

Warranty

The Lord Corporation warranties the computer for three (3) years and all other parts (microphones, speakers, accelerometers, and control box) for one (1) year starting on the first day of system operation after installation.

To Learn More About NVX Active Noise Control

If you're a King Air owner or operator and you're interested in installing an NVX Active Noise Control System in your aircraft, please contact the Service Center of your choice.

Authorized NVX Service Centers

For more information about Lord NVX Active Systems and their aircraft applications, send an email message to Becky Weih at becky_weih@lord.com or call 919-468-5981, ext. 6402.

NVX is a trademark, and Lord is a registered trademark of Lord Corporation.