FAA Aviation Mechanic Powerplant (AMP)Turbine EnginesMedium
A turbine engine is equipped with accelerometers mounted on the compressor and turbine cases as part of an engine vibration monitoring system. What is the primary purpose of this system?
- ATo measure minute fuel flow fluctuations caused by fuel control unit malfunctions
- BTo detect excessive vibration levels, such as those caused by blade damage, imbalance, or bearing wear, before a major failure occurs
- CTo measure exhaust gas temperature spikes during rapid throttle movement
- DTo calculate engine pressure ratio changes during climb power settings
Show answer & explanationAnswer & explanation
Correct answer: B. To detect excessive vibration levels, such as those caused by blade damage, imbalance, or bearing wear, before a major failure occurs
Engine vibration monitoring systems use accelerometers to sense abnormal mechanical vibration, which can indicate developing problems such as compressor/turbine blade damage, rotor imbalance, or bearing wear, allowing maintenance action before catastrophic failure.
Why the other options are wrong
- A. Fuel flow is measured by flow transmitters, not vibration sensors.
- C. EGT is monitored by thermocouples, not accelerometers.
- D. EPR is calculated from pressure probes, unrelated to vibration sensing.
Engine Vibration Monitoring
A system using accelerometers on the engine case to detect abnormal vibration levels indicating imbalance, blade damage, or bearing wear.
- Accelerometers convert mechanical vibration into electrical signals
- Cockpit vibration indicator alerts crew to abnormal readings
- Early detection helps prevent catastrophic mechanical failure
Memory trick: Vibration sensor = the engine's pulse monitor for shaking sickness