The UK’s Civil Aviation Authority has banned the Boeing 737 MAX from operating in or over UK airspace “as a precautionary measure”.

The decision comes after an Ethiopian Airlines Boeing Max 8 crashed on Sunday, killing 157 people on board, the second fatal accident involving that model in less than five months

The UK joins Malaysia, Singapore, China and Australia, in banning the aircraft. The CAA said the directive would remain in place until further notice. Tui Airways and Norwegian both operate the Boeing Max 8 in the UK as part of their fleets.

“The UK Civil Aviation Authority has been closely monitoring the situation, however, as we do not currently have sufficient information from the flight data recorder we have, as a precautionary measure, issued instructions to stop any commercial passenger flights from any operator arriving, departing or overflying UK airspace,” a CAA statement said.

A Tui statement confirmed their 737 Max 8 aircraft were grounded following the CAA’s decision.

“Any customers due to fly home today on a 737 MAX 8 from their holiday will be flown back on another aircraft.

“Customers due to travel in the coming days will also travel on holiday as planned on other aircraft,” Tui said in a statement.

Which other countries are affected?

Singapore’s Changi Airport is the world’s sixth busiest and a major hub connecting Asia to Europe and the US.

But only a handful of airlines operate Max aircraft in and out of the country.

No Australian airlines operate the Boeing 737 Max, and only two foreign airlines – SilkAir and Fiji Airways – fly the model into the country.

Shane Carmody, who is in charge of aviation safety at Australia’s Civil Aviation Safety Authority, said the suspension would remain in place while the organisation awaited “for more information to review the safety risks”.

Several airlines and regulators around the world have already grounded the Max 8 model following the crash.

South Korea has asked Eastar Jet, the only airline in the country to own Max 8s, to ground its planes from Wednesday, while Malaysia has banned the jets from its airspace, according to the AFP news agency.

Singapore’s aviation authority said the affected airlines include SilkAir, which operates six Boeing 737 Max 8 aircraft, as well as China Southern Airlines, Garuda Indonesia, Shandong Airlines and Thai Lion Air.

In the US, the country’s Federal Aviation Administration (FAA) told airlines on Monday it believes Boeing’s 737 Max 8 model to be airworthy, despite the two fatal crashes.

Southwest, which has the largest fleet of 737s in the US, said it was offering customers booked on flights using the jet the chance to change their reservation, but would not be offering refunds.

Rival American Airlines said its “standard policies for changes still apply”.

What is a Boeing 737 Max aircraft?

The Boeing 737 Max fleet of aircraft is the latest in the company’s successful 737 line. The group includes Max 7, 8, 9 and 10 models.

By the end of January, Boeing had delivered 350 of the Max 8 model out of 5,011 orders. A small number of Max 9s are also operating.

The Max 7 and 10 models, not yet delivered, are due for roll-out in the next few years.

The Max 8 that crashed on Sunday was one of 30 ordered as part of Ethiopian Airlines’ expansion. It underwent a “rigorous first check maintenance” on 4 February, the airline said.

Following last October’s Lion Air crash in Indonesia, investigators said the pilots had appeared to struggle with an automated system designed to keep the plane from stalling, a new feature of the jet.

It is not yet clear whether the anti-stall system was the cause of Sunday’s crash. Aviation experts say other technical issues or human error cannot be discounted.

Eyewitnesses say they saw a trail of smoke, sparks and debris as the plane nose-dived.

What have US authorities said?

US aviation officials have said the 737 Max 8 is airworthy and that it is too early to reach any conclusions or take any action.

Boeing has confirmed that for the past few months it has been developing a “flight control software enhancement” for the aircraft.

Paul Hudson, the president of FlyersRights.org and a member of the FAA Aviation Rulemaking Advisory Committee, nonetheless called for the plane to be grounded.

“The FAA’s ‘wait and see’ attitude risks lives as well as the safety reputation of the US aviation industry,” Mr Hudson said in a statement on Monday.

BBC NEWS