Handling the Engine

Vibration

Excessive vibration in flight may be caused by an engine, propeller, drive system, or airframe problem.

If unusual vibration occurs:

• assess whether the vibration appears to be coming from the engine, propeller or airframe
• monitor the engine instruments
• consider whether changing power affects the vibration
• decide whether a precautionary landing is required

If the vibration is severe or an engine or propeller problem is suspected, reduce power as appropriate and land as soon as safely practicable.

Key point

Unusual vibration should never be ignored. Assess the cause and determine whether a precautionary landing is necessary.

The Engine

An aircraft engine converts the chemical energy in fuel into mechanical energy to produce power.

In a spark-ignition engine, the ignition system produces a spark at the spark plug to ignite the fuel-air mixture in the cylinder.

During normal operation, the spark occurs before the piston reaches Top Dead Centre (TDC) so that combustion pressure develops at the correct time.

During engine starting, the ignition timing is normally retarded.

This means the spark occurs later than during normal running.