Sonic boom: RAF jets escorting plane to Stansted Airport was reason for sonic boom in England

A plane that lost communication because of a malfunction was escorted to safety by RAF jets, police have said.

People had reported hearing sonic booms across Leicestershire and Northamptonshire at about midday on Saturday (4 March). The plane had two people on board and was flying from Iceland to Nairobi via Southend when it lost contact and had to be escorted to Stansted Airport.

The sound, which many have also described as being like a sonic boom, caused confusion and concern in the midlands. Residents have been advised that there is no need to be concerned about it.

Leicestershire Police were flooded with calls following the curious incident earlier today. A video shared on social media captured from a security camera recorded the moment the boom could be heard.

However despite some concerns that it might have been an explosion, it is nothing to be worried about the force has said. People have reported hearing the sound throughout central England.

What have police said?

A spokesman for Essex Police said: “A flight has been diverted to Stansted Airport after communications with the pilot had been lost. The plane, which had been flying from Iceland to Nairobi via Southend was escorted to the airport by RAF jets and landed shortly before 12.50pm today. Two people, a pilot and co-pilot, were on board.

“Officers engaged with them and carried out inquiries and are satisfied there was a loss of contact due to an equipment malfunction and nothing of any concern. The plane and those on board have now been released to continue their journey.”

Earlier in the day, Leicestershire Police’s official account wrote: “We have received numerous calls in relation to a large explosion sound heard from various parts of the city and county. We like to reassure you that there is no concern however thank you for your immediate response to us. All reactions:181181.”

Ministry of Defence confirm RAF jets were dispatched

The Ministry of Defence (MoD) confirmed that Typhoon fighter jets were sent from RAF Coningsby in Lincolnshire to help the aircraft. A spokesman said: “Typhoon aircraft from RAF Coningsby offered assistance to a civilian aircraft and were authorised to fly supersonic.”

The MoD said it always has jets under a “quick reaction alert” which respond to any aircraft that cannot be identified or is not communicating with either civilian or military air traffic control. Typhoon fighter squadrons are positioned at RAF Coningsby, RAF Lossiemouth in Scotland and in the Falkland Islands.

Where was the sound heard?

Social media users across the midlands and central England have reported hearing the sonic boom or ‘explosion’ earlier on Saturday. Leicester is just one of the places were residents heard the sound.

One person wrote: “I think I just heard a #sonicboom in #Witney. Did anyone else hear it?” Others said they heard it in Warwickshire, Banbury, Oxford and more.

Aarondeep Mann, 22, heard the bang in Houghton-on-the-Hill, Leicestershire, and said his first thought was it may have been a gas explosion. “It was the most random, loud thing we’ve ever heard as we were clearing the boot of the car out,” Mr Mann, a practice manager, told the PA news agency.

“First thoughts were that it could be a gas pipe explosion. All the neighbours came out as the houses were practically shaking.”

What could be the cause of the sonic boom?

The account Aviation Highlights on Twitter suggested the dramatic sound might have been caused by Typhoon fighters. They explained: “RAF Typhoons scrambled to intercept this Dash 8 aircraft which experienced radio failure and was heading to London. The fighters were reportedly supersonic on their way south from RAF Coningsby.”

The RAF’s Airbus Voyager, the air force’s only in-flight refuelling plane, was being tracked by at least 1,440 people on Flightradar24 – a site that tracks aircraft in real time.

What is a sonic boom?

A sonic boom is caused by an object travelling faster than the speed of sound. Aircraft are one of the more common reasons for a sonic boom. When planes fly, they create sound waves whilst travelling through the air.

When travelling at a speed slower than the speed of sound, the sound waves are out in front of the plane. If the aircraft travels faster than the speed of sound, therefore breaking the sound barrier, it will create a sonic boom as it flies past.

For the duration of the plane flying faster than the speed of sound, sonic boom will be dropped in its flight path.

What is the ‘Speed of Sound’?

The speed of sound often varies given the conditions of atmosphere and other surrounding factors, but in dry air at 20°C the speed of sound is roughly 768 mph.

What was the strongest sonic boom recorded?

The strongest sonic boom ever recorded was 144 pounds per square foot and it did not cause injury to the researchers who were exposed to it. The boom was produced by a F-4 flying just above the speed of sound at an altitude of 100 feet. For some perspective, community exposure to sonic boom is below two pounds per square foot.