Squawk codes are a series of numbers that jets use to communicate to air traffic control. Here's what it means when a jet is squawking 7700.

The jet sent out an emergency Squawk 7700 code, which translates to an “emergency situation.” It is believed the jet was experiencing engine failure. The B-52 bomber circled the area in a loop ...

But the pilot issued a 700 squawk code alert over Stoke-on-Trent. The plane was diverted to Birmingham Airport at around 7.30am.