Johannesburg - It was surely a sight that would have left many curious minds baffled - a five-engined Boeing 747.
Those with an interest in aviation will know that the jumbo uses Rolls-Royce engines to fly and needs only four - with two mounted on each wing. However, that wasn't the case when Qantas flight QF63 left Sydney, Australia on Wednesday for Joburg.
In addition to the four engines that helped it fly, it also carried a 10-ton extra engine.
However, that engine was not powering the flight as it was being brought to Joburg to replace another in a plane that was grounded.
According to Qantas’s Will Lehmertz, carrying an extra engine on a plane was not unheard of.
Normally when one of their planes is grounded and an extra engine is needed, they would have to ship it from Australia to South Africa - a process that could take weeks. In other instances, they would charter freighter aircraft.
This time, however, they decided to give the extra engine “a lift” in a plane coming to South Africa to reduce the amount of time needed to get their grounded plane up and running. Lehmertz said their engineers made this possible.
“The wing of the aircraft is fitted with anchor points, which allow 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. It is fitted between the body of the aircraft and the innermost engine on the port side of the aircraft, and adds extra weight and drag to the aircraft.
“That means that the plane had to do a quick refuelling stop in Perth.
“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.”
Lehmertz said that after flight QF63 landed in Joburg, they would just have to remove the fifth engine and put it onto the aircraft that will operate QF64 to Sydney.
Lehmertz said they first pioneered the carriage of a fifth engine with Boeing 707s back at the dawn of the jet age to save shipping costs.
“We’re undertaking this rare task to get our customers and our aircraft on their way as quickly as possible,” he said.
The Star