Respect the Starter Motor Duty Cycle
Follow the starter duty cycle to avoid overheating and damage – e.g. in ELA: crank no more than 10 s, cool 20 s between attempts, and rest 30 min after six tries.
1 min readKapiti Aero Club safety team
Most starter problems happen because pilots don't fully understand the aircraft's starting system and the stress the starter is under when you turn the key.
Stick to the starter's duty cycle to maximise its life. The duty cycle determines how well the starter tolerates repeated starting attempts: each unsuccessful attempt should be followed by a specified cool-down interval. Ignoring this will overheat the starter and severely damage its internal components, leading to premature failure.
Violating the duty cycle just a couple of times can do irreparable damage. In extreme cases the starter can become inoperable – and then you're stuck. Excessive cranking can also overheat the electrical supply system, accelerate wear on the contactor and increase corrosion of connections in the circuit.
Our maintenance team has seen damage to starter motors from excessive cranking, so always follow the guidelines for your aircraft. For example, in ELA (one of our C152s):
- Don't crank the starter for more than 10 seconds.
- Allow 20 seconds to cool between attempts.
- Repeat up to 6 times, then allow the starter to cool for 30 minutes.