Engine vibration monitoring (EVM) systems for aerospace

Engine vibration monitoring systems record engine rotor vibration levels and exceedances and detect if the rotors are out-of-balance.

Peace of mind for the complete measurement chain

Installed in the aircraft electronics bay, engine vibration monitoring units (EVM) acquire and process the signal from accelerometers installed on or in the engines. The use of rotational speed inputs and tracking filters enables a focus on specific frequencies within the vibration spectrum. EVMs provide pilots with information about the vibration levels of engine rotors, as well as warnings in case of exceedances. Such rotor unbalance monitoring systems are mandatory for jet powered civil aircraft for revenue passenger transport.

Beside real-time monitoring, EVMs gather and archive engine vibration data (amplitude and phase) for post-flight cold fan trim balancing (CFTB). This operation consists of fitting prescribed weights to optimise the rotor balancing for pre-defined flight conditions. Regular CFTB will result in increased passenger comfort (reduced noise) and decreased parts wear. The ability to perform these adjustments without costly engine runs and significant disruptions of flight schedule is of great benefit to the operators.

Advanced vibration monitoring functions have been built in more recent EVMs to closely monitor the health of bearings and other engine components.

With over 60 years of experience in developing electronics for airborne vibration and condition monitoring systems, Meggitt Switzerland can offer vast know-how from analogue pre-processing electronics through to state-of-the-art digital signal processing and diagnostics software. Be it for large or regional aircraft or business jets, we are in a unique position to provide a turnkey system capability, thus ensuring the best performance and reliability throughout the overall measurement chain. The vast majority of current transport aircraft rely on our engine vibration monitoring systems to monitor the condition and health of their engines.

Typical EVM system architecture

A typical system architecture, consists of:

  • Two engine mounted piezo-electric sensors (one directly installed on the fan bearing and one mounted on the turbine casing).
  • Low noise cable assemblies/remote charge converters to reliably convey the vibration signal up to the EVM
  • A front panel display on the EVM or cockpit maintenance terminal allowing operators to easily access system BITE messages, measured vibration values, fan and LPT balancing recommendations (amongst others)
  • A front panel maintenance connector providing raw signals for engine troubleshooting and also allowing the upload and download of operational software

We have the in-house capability and experience to provide the complete system including engine sensor suite, cabling, signal conditioning, data processing and integration with aircraft systems.

Vibration sensors

Please visit our vibration sensors page for further details.

We work hand-in-hand with engine OEMs to optimise our solutions for each individual application.

Features and benefits

  • Installed in the aircraft electronic bay
  • Broadband vibration monitoring
  • Narrowband (tracking) vibration monitoring
  • Cold fan trim balancing
  • Advanced bearing monitoring algorithms
  • Gearbox vibration monitoring.


  • Our engine vibration monitoring systems are used on nearly all civil transport aircraft
  • Advanced airborne vibration monitoring unit (AAVM) standard fit on many civil transport aircraft
  • Integrated engine vibration monitoring unit (IEVM) specifically designed for integration with modular avionics for vibration monitoring in regional aircraft and high-end business jets

At Meggitt, we can provide you with a sensing and monitoring solution that is specific to your aerospace application and can be further customised to your particular requirements. To discuss what you need in more detail, contact us.

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