Wikipedia
Walk-around
In aviation, an outside check or walk around is the air crew inspecting certain elements of an aircraft prior to boarding for security, safety, and operational reasons.
The pilot primarily inspects outside parts of the aircraft he will steer, e.g. control surfaces, tires and possible leaks from fuel or oil.
Usage examples of "walk-around".
She was engrossed in her walk-around checks and Craig realized she was to be their pilot.
Jake did a walk-around preflight check with his flashlight set for white light because in red light any red hydraulic fluid leaking from the plane would be almost invisible.
Relke sprinted a few steps to the emergency rack and grabbed a low pressure walk-around bottle.