Are older planes less reliable?
A Boeing 737 belonging to British airline Jet2, has made two emergency landings in two weeks causing commentators to question the reliability of old planes.
The plane was first forced to land at Barcelona, as it flew from Ibiza to Leeds. Twelve days later, it made another forced landing at Frankfurt while flying from Newcastle to Prague.
The airline has said there was no compromise of passenger safety during both emergency landings.
People have been pointed out that the plane which was manufactured in 1986, could be having trouble because of its age.
Patrick Smith, US pilot and author of Cockpit Confidential, doesn’t agree.
"Commercial aircraft are built to last more or less indefinitely, which is one of the reasons why they're so expensive," he said.
"It's common for a jet to remain in service for 25 years or more.”
Smith explained that as planes get older, they undergo greater scrutiny.
"Inspection criteria grow increasingly strict," he said.
Why planes retire after 30 years
"Planes are sold, traded or mothballed not because they've grown old and are falling apart, but because they've become uneconomical to operate," said Smith.
"Aircraft are tailored to particular roles and markets, and there's a fragile balance between whether it makes or loses money. Poor performance means quick exit to the sales block. To another carrier with different costs, routes and needs, that same aircraft might be profitable."
An older plane, tends to have depreciating economic value as fuel-efficient aircrafts enter the market.
New aircraft also tend to give passengers a more comfortable flying experience and are quieter than older planes.