A Ryanair plane bound for Dublin had to return to Porto moments after take off after a passenger reportedly claimed she was being followed by three people. After the flight attendant communicated the alarming claim to the pilots, they sent a squawk code to air traffic controllers that’s used to discreetly signal hijacking. Air traffic control then instructed the captain to turn around and return to Porto airport.
What is a squawk code?
A squawk code is a four-digit number that pilots put into the transponder so air traffic control can identify and track the plane on the radar, and the code ‘7500’ signals the aircraft has been hijacked. On Reddit, a person asked if there is any “secret communication” between air traffic control and pilots, and a former pilot explained: “I suppose the closest to what you're thinking about might be the emergency transponder codes?
“Each flight is given a code for their transponder, but if a plane is in trouble, then they can change it to a special code. The closest to a secret one would be the one for if you've been hijacked, because I suppose you can hope the hijackers don't know it. But it's 7500, so now you know at least.”
What happens when you squawk 7500?
But what exactly happens when you squawk 7500? A former air traffic controller explained that the first thing they do is verify the code was not dialled by mistake without saying the numbers “7500” over the radio. For instance, they would ask the pilot to confirm their squawk code, then assess the pilot's response.
“I’ve been the interceptor on a few 7500 squawks. There’s usually a long process involving ATC making sure you’re not just a weekend warrior with fat fingers before they launch alert fighters.”
Ryanair incident details
Former TAP pilot and aviation author Jose Correia Guedes said on X: “The Ryanair Boeing 737-8 MAX with registration EI-IJK took off from Porto bound for Dublin.
“Upon passing FL120, the captain entered code 7500 into the transponder, signalling an attempted hijacking or intrusion into the cockpit. With the assistance of Air Traffic Control, the B737 landed without problems at Porto near midnight, and the PSP police took charge of the incident.
“When code 7500 is entered into an aircraft's transponder, an alarm is automatically triggered on the air traffic controllers' panels. This is followed by a confirmation because sometimes the code is entered by mistake, after which notification is made to the authorities and emergency services.
“Then, air traffic control establishes a privileged communication with the crew and provides all possible support until the problem is resolved. So far, I haven't been able to confirm whether there was an attempted hijacking or if it was just a misbehaving passenger who caused this incident. In either case, the aforementioned passenger now has a big problem to deal with.”
