This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
BN mec turning prop. Nakajima BN before starting the engine The mechanic is manually turning the prop to prevent hydraulic lock hydraulic lock occurs in cylinder when it gets full of oil and the connecting rod attempts to displace it Liquids are not compressible so it will bend or possibly break the connecting rod This used to be