A non-responding United Boeing 767 flying over France has instigated a sonic boom as fighter jets have raced to intercept the aircraft. The plane was able to re-establish communications with the ground via the French Air Force aircraft and continue on its journey.

United
The Boeing 767-300ER painted in the new United livery. Photo: United Airlines via Twitter

What are the details?

United Airlines flight UA-121 had just left from sunny Barcelona to head back towards Newark, NJ, in the USA when it lost radio communication over France according to The Aviation Herald.

Flight AWare
The route of the aircraft. Photo: Flight Aware

Whilst this event is unusual, it can happen when an aircraft fails to connect with ground control either due to a technical reason, interference or error. In these cases (and I am not a pilot nor traffic control so do take this with a grain of salt), the plane will try to re-establish communications and remain on its current course.

Any other aircraft in the area will be routed around the affected aircraft by ground control until they can get back in touch.

However, if an aircraft does not respond for a considerable amount of time, then air traffic control might start to get nervous. They get even more nervous if that aircraft just entered their country's airspace, which is frequent when traveling across Europe.

This was the situation with the United Boeing 767-400 (registration N78060) which had just crossed the border from Spain into France. The aircraft didn't reply to communications so French air traffic control escalated the issue.

What happened next?

The next stage was to establish close communication. To do so, French Rafale fighter aircraft were scrambled to intercept the plane.

The jets took off with a roar and kicked in the afterburners, blowing out a sonic boom to catch up to the aircraft. Sonic booms are a rolling sound wave that can be louder than a car door slamming next to your ear, kicking up a wake affecting other aircraft and, in extreme scenarios, shattering windows below. If you were standing on the ground at the time, it would sound like a thunderclap without the lightning.

United 767
A United Airlines plane (File photo). Photo: Tom Boon/Simple Flying

The fighter jets pulled up alongside the aircraft and were able to re-engage in radio communication to assess that everything was okay. The aircraft was told to remain on course until they connected them through to ground control, approximately an hour later.

Once communications were re-established, the jets peeled off and the United aircraft continued to fly onwards back to the United States. It finally landed without any further issues eight hours later.

Simple Flying has reached out to United for their take on this situation.

"After experiencing a brief communications issue during handoff from Spanish to French controllers, our crew on board United flight 121 from Barcelona to Newark completed the necessary procedures and regained communications with air traffic control.  The flight safely continued to its destination."

We would love to receive a comment on how the pilots reacted to a fighter jet pulling up alongside as they sped over France.

What do you think? How would you have reacted? Let us know in the comments.