night, westy
Comparison of Pilot traditions:
Navy: On a carrier, the Naval Aviator looks over at the Catapult Officer ("Shooter") who gives the run up engines signal by rotating his finger above his head. The pilot pushes the throttle forward, verifies all flight controls are operational, checks all gauges, and gives the Cat officer a brisk salute, continuing the Navy tradition of asking permission to leave the ship. The Cat officer drops to one knee while swooping his arm forward and pointing down deck, granting that permission. The Navy pilot is immediately catapulted airborne.
Air Force: We've all seen Air Force pilots at the air base look up just before taxi for takeoff and the ground crew waits until the pilot's thumb is sticking straight up. The crew chief then confirms that he sees the thumb, salutes, and the Air Force pilot then takes off. This time-tested tradition is the last link in the Air Force safety net to confirm that the pilot does not have both thumbs up his @ss on takeoff.