(Picture: AP Photo/Craig Mitchelldyer)
Boeing is in the spotlight after an Alaska Airlines plane lost a door panel shortly after take-off on Friday and was forced to make an emergency landing.
The Boeing 737 Max 9 jet had been in service for just eight weeks when a chunk of the fuselage blew off at 16,000ft, leading pilots to return to the departure city of Portland, Oregon.
There were 177 passengers and crew on board the flight to Ontario, California.
The US Federal Aviation Administration has since ordered the temporary grounding of all 737 Max 9 planes.
But this is not the first time that the safety of the 737 Max has come under scrutiny.
In October 2018, 189 people died when a 737 Max crashed in Indonesia. Five months later, 157 were killed in a 737 Max crash in Ethiopia.
The Boeing 737 Max 9 jet had been in service for just eight weeks when a chunk of the fuselage blew off at 16,000ft (Picture: Reddit)
Which airlines use Boeing 737 Max?
There are three versions of the Boeing 737 Max in action worldwide: the Max 8, the Max 8-200, and the Max 9.
The Max 9 plane, which was the version involved in the Alaska Airlines incident on Saturday, is currently used by 11 airlines.
Alaska Airlines has grounded its entire fleet of Max 9s, leading to 160 cancelled flights.
United Airlines, Aeromexico, Turkish Airlines and Copa Airlines have said that they are currently carrying out inspections on their 737 Max 9s.
Flydubai and Icelandair said that they were not affected by the grounding and they will continue to operate their Boeing 737 Max 9 fleet.
Several airlines use older versions of the 737 Max.
Ryanair has 139 Max 8-200 planes which fly several routes between the UK and European cities. TUI Group has 38 Max 8 planes.
No UK-registered Boeing 737 Max 9s have been grounded, which means no flights to or from the UK are currently affected by the US Federal Aviation Administration’s grounding order.
Ethiopian Federal policemen stand at the scene of the Ethiopian Airlines 737 Max plane crash, near the town of Bishoftu, southeast of Addis Ababa, Ethiopia on March 11, 2019 (Picture: Reuters)
What happens in a ‘blow out’
When a plane gains altitude, the air pressure outside the cabin becomes lower than the air pressure in the cabin.
This difference in air pressure means that if there’s a hole in the fuselage – the body of the plane – the air from inside the cabin immediately rushes out, often at a very high speed.
Anything not secured could be sucked out of the opening. This is called an explosive decompression, or a ‘blow out’.
In 2018, a woman died after she was partially sucked out of a smashed window on a Boeing 737 flight in Philadelphia. The plane engine exploded and debris from it hit the window.
A hole in the plane fuselage can happen for several reasons. Cracks in the fuselage can be caused by ‘metal fatigue’, which is when the metal is worn down from use over the years.
Cracks can be common. The older the aircraft, the more likely that it will have cracks in the fuselage.
US aviation investigators have not yet determined what caused the door panel section of the Alaska Airlines flight to blow out.
One passenger said that a child’s shirt was sucked out of the hole in the Alaska Airlines plane. (Picture: NTSB/SWNS)
How to check what plane you’re flying in
When booking a flight, the aircraft type is usually listed under ‘flight details’ on the reservations page.
You can also find out what type of plane you’ll be travelling on by searching on Google Flights. Simply enter your flight details and select your flight to see the aircraft type.