Staying in Touch

When a plane is flying over an ocean far away from land, pilots used to endure the hissing, crackling noise of their HF radio constantly in case anyone tried to contact them. There is now a system that does the listening for the pilot. When controllers want to contact a pilot, they send a radio signal to the plane. Each aircraft has its own address code. Many airplanes may receive the signal, but the system in only one specific plane recog­nizes the address code and alerts the pilot. It sounds a chime and flashes a light in the cockpit. This tells the pilot that someone is trying to contact that particular plane.

Even when HF radio is being used for long-distance communication, an air­craft’s VHF radio is not switched off. Pilots leave it on and listen for messages from pilots in nearby aircraft. A pilot who suffers serious turbulence, for example, can warn other pilots so that they can find a way around it.

Commercial pilots also can send and receive short text messages. They use this for standard messages, such as weather reports. The messages appear on a screen and can be printed out on paper using the cockpit printer.

The amount of information sent and received by pilots and aircraft has increased over the years, and it will con­tinue to increase. In the future, aircraft may be able to use broadband links that can transmit live video from the cockpit and cabin, as well as giving the crew and passengers access to the Internet during a flight.