This is the moment a plane took off with an extra engine strapped to its wing.

Qantas QF63, a Boeing 747-400, was transporting the spare engine from their engineering headquarters in Sydney, Australia, to Johannesburg in South Africa, where it will be fitted to another 747.

The additional engine was attached between the body of the plane and the innermost engine on the port (left-hand) side of the aircraft.

Qantas said it chose to fly the engine over rather than ship it across by boat or chartering a freight plane so that it could get customers and their aircraft on their way quicker.

The only change to its normal service was a refuelling stop in Perth, where one Twitter user caught the rare sight of a five-engined jumbo taking off.

A statement from the airline explained how it was achieved.

“The wing of the aircraft is fitted with anchor points, which allows a supporting strut to be attached under the wing.

“The strut is fitted with a winching mechanism so the engine can be hoisted up and secured safely for its journey.

“The fifth engine adds extra weight and drag to the aircraft, meaning the flight had to make a quick refuelling stop in Perth.”

The statement explained: “Additional drag is caused by air travelling around the spare engine during flight and, to counterbalance this, our pilots are trained to use the flight controls to ensure the aircraft flies straight, level and safely.

“Once QF63 has landed in Johannesburg – it’s simply a matter of removing the fifth engine and then putting it onto the aircraft that will operate QF64 to Sydney.”

2011 was the last time Qantas carried an extra engine on a Boeing 747, 9 News Australia reported.

Video credit: Qantas