A make of passenger plane called the Boeing 737 Max has been grounded because of questions over safety.
The 737 Max is flown by airlines all over the world for short trips.
But 371 of the planes won't be allowed to fly again until tests are done into why there have been problems.
In Europe, 15 planes from travel company, Tui, have been banned from flying.
The Boeing 737 Max is a passenger plane made by US plane maker, Boeing. It carries up to 210 passengers.
It's quite new, having only been used since 2017 and there are just over 7,000 Boeing 737 Max-8 flights a week across the world. That's close to 1% of global flights.
In Europe, 15 of the planes are operated by travel company, Tui.
Now the safety of the plane has hit the headlines after two accidents in the last six months.
On 28 October 2018, there was an accident involving a Boeing 737 Max plane called the 737 Max-8 in Indonesia. 189 people died.
There was another accident this year on 10 March in Ethiopia. 157 people died.
Following the most recent accident, governments around the world including the UK, China, India and Australia made moves to ground the 737 Max.
US officials initially refused to ground the aircrafts but then changed their mind after an investigation.
The US Federal Aviation Administration (FAA) has said all Boeing 737 Max 8 and 9 aircraft will remain grounded at least until May.
The plane-maker Boeing has now taken the decision to take all of its 737 Max planes out of action worldwide.
Altogether 371 planes have been withdrawn from service.
Boeing says it will now try to work out why the accident in Ethiopia happened.
Flying is a very safe mode of transport and it's a lot safer than travelling in a car.
In 2015, for example, there were 37.5 million flights across the globe and a total of 68 accidents.
To put that in perspective that's 0.00000181% of all flights.
Most modern planes have four engines but can land using just one engine if the others aren't working.
A spokesperson from Tui UK - the travel company who use Boeing 737 Max planes in Europe - has told Newsround that anyone with flights around the Easter holidays could face minor delays but that passengers will still be able to get to where ever they're travelling to with minimum fuss.