Would you feel uneasy about flying on a plane built in 1974? Harold Wilson was enjoying his second stint in Number 10, the band Queen was in its pomp, man's first small step on the surface of the moon was still relatively fresh in the memory.

And 1974 was also the year that a Boeing 737-200, with the serial number 20836, made its maiden flight for Transavia Airlines, based in the Netherlands.

Forty-five years on, Harold Wilson has shuffled off this mortal coil, as has Freddie, while Nasa is hoping to start a colony on Mars. But 20836 is still going strong in the services of Nolinor Aviation, a Canadian charter airline, under the registration C-GNLK.

Its journey from Holland to Quebec has been a circuitous one. After leaving the low-cost Dutch airline in 1977 it went to Saudia, and then Aerolineas Argentinas. Next up was the now-defunct Australian Airlines, followed by Air Florida, another former carrier. MarkAir, based in Alaska (also deceased), came next, before a stint as a cargo plane. In 2004, it went to Peru. In 2006, it was bought by the short-lived Italian airline Voliamo. In 2008, CityLine Hungary – which ceased trading in 2015 – snapped up the well travelled 737.

Since 2014, however, it has been in the services of little Nolinor Aviation, based in Mirabel, a suburb of Montreal, which serves a handful of domestic destinations using a fleet of 18 aircraft. At 45 years, it is, according to the database of Airfleets.net, the world's oldest passenger plane still in service.

So would you feel safe on board? The reliability of elderly aircraft is occasionally raised, such as in 2017 when a 31-year-old Jet2 plane, also a 737, made two emergency landings in as many weeks.

Passengers were never at risk, Jet2 said, but commentators were quick to point out the age of the aircraft. Registered as G-CELI, it was manufactured in 1986 for Lufthansa, making it almost as old as this reporter. And those problems signalled the end of its many years of service – two months after the incidents, G-CELI was placed in storage and then scrapped “due to failures on board the aircraft” and “failed” repairs. The oldest active plane in the Jet2 fleet is now the 15-year-old G-CELY.

But are older planes really more likely to go wrong?

Not according to Patrick Smith, a US pilot and author of Cockpit Confidential.

“Commercial aircraft are built to last more or less indefinitely, which is one of the reasons why they’re so expensive,” he told Telegraph Travel.

“It’s common for a jet to remain in service for 25 years or more.”

Smith claims that as planes get older they come under ever greater scrutiny. “Inspection criteria grow increasingly strict,” he said.

Even still, it's rare to maintain and operate an aircraft as venerable as Nolinor's 737. According to Airfleets.net, which carries records for 41 models, the only older jets still active are in the hands of cargo firms and air forces. Caspian Airlines, for example, has a 49-year-old 747 (registration: EP-CQB) that once belonged to TWA – but it is used for transporting goods, not people.

Conviasa, a Venezuelan passenger airline, has a 737 (registration: YV3434) that dates back to 1976, Air Inuit, based in Canada, has one that was born in 1978, RUTACA, another carrier from Venezuela, has one from 1979.



Indeed, almost all of the most elderly aircraft still being flown belong to small airlines in far-flung places.

Iran Air has an A300 from 1980, for example, while African Express Airways, based in Kenya, has a McDonnell Douglas MD-8O made in 1984.

The McDonnell Douglas MD-80 is still widely used Credit: GETTY

In all likelihood you haven't flown with any of these minnows, but step a little closer to the modern day and the big boys soon start cropping up.

Of the major players, Delta and British Airways have some of the oldest fleets.

Delta, whose 909 aircraft have an average age of 15.2 years, has a 30-year-old 757, and a clutch of 32-year-old MD-80s. The average age of the BA fleet is 13.7 years, but its oldest aircraft is a 747, registration G-BNLY, which it received on February 2, 1993.

So have you flown on any of these esteemed birds? It's easy to find out, thanks to the tracking website FlightRadar24.

G-BNLK, BA's most stately jumbo, is currently en route from Heathrow to Nairobi. Delta's oldest aircraft, registration N905DL, is currently flying in and out of Atlanta.

There is another option for fans of elderly aircraft, however. The Airfleets.net database is not exhaustive and a Telegraph Travel reader has pointed us in the direction of Buffalo Airways, a family-run Canadian firm. It owns a handful of DC-3s, a model that has been out of service since 1950. Scheduled passenger flights were suspended a few years back, but they are available to charter.