| Health and usage monitoring systems are a common | | | | major component or system failure. |
| component in the flight deck avionics of a modern | | | | Pressure measurement: a tendency to over-pressure |
| aircraft. The parameters which may be monitored by | | | | or low pressure may be an indication of impending |
| health and usage monitoring systems are extensive | | | | failure or a loss of vital system fluids. |
| and may depend to some degree upon the precise | | | | Acceleration: higher acceleration readings than normal |
| engine/gearbox/rotor configuration. Listed below is a | | | | may indicate that a component has been |
| range of typical parameters together with the reason | | | | overstressed or that abnormal wear is occurring. The |
| for their use. | | | | use of low-cycle fatigue algorithms may indicate blade |
| Speed probes and tachometer generators: the | | | | fatigue which could result in blade failure. |
| measurement of speed is of importance to ensure | | | | Particle detection: metal particle detection may |
| that a rotating component does not exceed limits | | | | indicate higher than normal metal composition in an |
| with the risk of being overstressed. | | | | engine or gearbox oil system resulting from abnormal |
| Temperature measurement: exceeding temperature | | | | or excessive wear of a bearing which could fail if left |
| limits or a tendency to run hot is often a prelude to a | | | | unchecked. |