Landing Signal Officer

A Landing Signal Officer (LSO) is a Naval Aviator specially trained to facilitate the "safe and expeditious recovery" of naval aircraft aboard aircraft carriers. Originally LSOs were responsible for bringing aircraft aboard ship using hand signals. Since the introduction of optical landing systems in the 1950s, LSOs assist pilots by giving information via radio handsets.

In the U.S. Navy, aircraft carrier operations began with USS Langley (CV-1) in 1922. Langleys initial flight operations were on an experimental basis to learn what worked and what didn't. The first pilots had no signaling system for assistance from shipboard personnel.Langleys first executive officer, Kenneth Whiting, had a hand-cranked movie camera film every landing to aid in evaluation of landing technique. When not flying, Commander Whiting observed all landings from the aft port corner of the flight deck. Commander Whiting's position remained visible to landing pilots in critical touchdown attitudes when the nose of the aircraft might obscure the pilot's view straight ahead. Pilots found Commander Whiting's body language helpful and suggested an experienced pilot be assigned to occupy that position, using agreed signals which evolved with experience. These Landing Signal Officers or Landing Safety Officers (LSOs) faced the incoming plane and held colored flags for improved visibility. Because LSOs used colored paddles, flags, or wands well into the jet age, the officers became unofficially known as "paddles" (US), or "batsmen" (UK). They are still referred thus to this day, and the LSO trade is referred to as "waving".

From the 1920s into the 1950s, U.S. and Royal Navy LSOs used a variety of signals to assist pilots landing aboard aircraft carriers. The signals provided information on lineup with the deck, height relative to proper glide slope, angle of attack (fast or slow), and whether the plane's tailhook and wheels were down.

The final signal was "the cut" (a slashing motion at the throat) ordering the pilot to reduce power and land the aircraft. In a properly executed landing, the aircraft's tailhook snagged an arresting wire that brought the plane to a halt. A "waveoff" was a mandatory order to abort the landing and go around for another attempt. Sometimes a proper approach drew a waveoff if the deck was "fouled" with aircraft or personnel in the landing area.

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