General

Morse code is a method of transmitting information as a series of on-off tones, lights, or clicks.  Morse code encodes the alphabet and numbers as standardised sequences of short and long signals called “dots” and “dashes”, or “dits” and “dahs”.  Pilots and air traffic controllers are usually familiar with Morse code and require a basic understanding.

Structure 

Each character is represented by a sequence of dots and dashes. The dot duration is the basic unit of time in code transmission. The duration of a dash is three times the duration of a dot. Each dot or dash is followed by a silence equal to the dot duration. The space between two characters is equal to 3 dots, and the space between words is equal to 7 dots.

SOS

Morse code SOS is sent by nine signals: 3 short, 3 long, and then 3 short.

This message can be sent by any signal method: 

1. Auditory – such as whistle or horn, 
2. Visual – such as flashlight or signal minor, 
3. Electronically – by radio with Morse key pad.

Code