Two RAF Typhoon fighter jets were scrambled to escort a Jet2 flight on Saturday after an apparent mix-up between air traffic controllers and the pilots.
The flight, which left Stansted Airport on Saturday evening, was headed for Turkey when there was allegedly disruptive behaviour from a female passenger on board.
The flight to Dalaman in Turkey was subsequently redirected back to Stansted Airport.
The incident was communicated to air traffic control.
However the Jet2 pilot was then overheard saying this: “Flight deck secure, cockpit door not compromised.”
It appears that the Jet2 crew were hoping to reassure air traffic controllers.
But air traffic controllers apparently interpreted that phrase to mean that someone had attempted to gain access to the cockpit during the flight.
In reality that was not the case.
It was, however, enough for air traffic controllers to alert their military counterparts.
Airborne within minutes
And two RAF Typhoon fighters were airborne within a matter of minutes.
This new explanation as to why the two fighter jets were scrambled comes from a pilot who was on board another plane in the vicinity of Stansted.
He therefore overheard the entire conversation between the Jet2 crew and air traffic controllers and spoke to the BBC anonymously because he was not authorised to do so by his airline.
The situation was “totally overdramatised” because of a “miscommunication”, he said.
The incident caused minor delays to other flights because other aircraft had to circle the airport whilst they waited for permission to land.
And the RAF Typhoons, which escorted the Jet2 airliner back into Stansted, caused a sonic boom.
Houses in the area shook and some residents thought it might have been an explosion and dialled ‘999’.
Jet2 has not commented on the latest explanation, nor has NATS, the company in charge of air traffic control at Stansted.
The decision to scramble aircraft to escort a civilian airliner in UK airspace is a split second one.
“You scramble and ask questions later”, says aviation safety expert David Gleave, who used to work for the RAF.
No time to muck about
“You don’t have time to muck about.”
He acknowledges that some people might see the incident as a waste of taxpayers money.
However he argues that it was probably a welcome opportunity for the RAF to practise procedures.
With RAF crews “sitting by their wing tips” and ready at any time, it should, he says, be regarded “as a useful test.”
Tony Reeves, from defence consultancy firm Level 7 Expertise, who also used to work for the RAF, said the Typhoons and their crews are kept on standby.
Even though the Jet2 incident was, ultimately, a false alarm they can be airborne within in a matter of minutes.
“They are armed-up and ready to deal with any type of incident.”
The standard protocol, he says, would be to get as close as possible to the aircraft in question and assess the situation.
In response to the claims that the two fighter jets were scrambled because of a miscommunication, the Ministry of Defence said it never discusses the detail of operational missions.
The 25-year-old woman who was arrested at Stansted Airport on suspicion of common assault, criminal damage and endangering an aircraft, was yesterday released on bail.
Jet2 has claimed that the woman had attempted “to open the aircraft doors during the flight”.
The BBC has been unable to reach the woman for comment.
Today Jet2 clarified that there was no attempt by anyone to access the cockpit.
The airline said the incident highlighted “just how serious the consequences of disruptive passenger behaviour can be.”