At the east coast of the USA is a big problem. The communication of the air control is broken. This affects many big airports. These are New York and Boston and Philadelphia.
The office says no planes can start. All planes must stay on the ground. This stops chaos in the air. Thousands of people wait for a long time. Many flights are late.
The reason is a fault in radio devices. Experts warn about old technology. Criminals can attack the systems. The office wants to make the flight security better.
