After installing an engine, what should be done with the propeller?

The appropriate action after installing an engine is to test the propeller before, during, and after engine operation. This ensures that the entire propulsion system is functioning correctly and safely. Testing allows for the verification of the propeller's balance, pitch, and overall performance in conjunction with the engine's functionality. It ensures that all components are properly integrated and that any potential issues can be identified and resolved before the aircraft is put into full operation.

Ensuring the propeller's readiness through testing is crucial for safety, as a malfunctioning propeller can lead to severe operational problems. Hence, routine testing during different phases of engine operation is a standard practice in aviation maintenance and promotes reliability and safety in flight operations.