Back in 2016, Qantas needed to get a new replacement engine to Johannesburg, South Africa, in a rush. The quickest way to get the engine there was to catch a lift on the wing of a Boeing 747. How did Qantas do it? And how did it affect the aircraft in flight?
What are the details?
Looking at the above picture, you might notice that there is something a little bit off. For those in the dark, it is that the Qantas Boeing 747 has an unbalanced engine configuration with two on one side and three on another.
We are no strangers to aircraft having strange engine configurations. Both Airbus and Boeing are known to add on a different engine to testbed aircraft (such as the new GE9X before installing it onto the new Boeing 777X).
But it is even rarer to see an extra engine on an aircraft, and an odd number at that. Only the Antonov 225 has more than four engines (six), and, it is not a commercial passenger aircraft.
Why did Qantas operate a commercial Boeing 747 flight with five engines? And how did they pull off this stunt?
Why did Qantas fly a fifth engine to South Africa?
According to Qantas, the carrier had a grounded Boeing 747 trapped in Johannesburg, South Africa, thanks to a broken Rolls Royce engine. Naturally, the Australian flag-carrier had plenty of spare parts back in Sydney (everything from screws, to seats, to engines) and didn’t want to go to the trouble of sourcing locally.
Thus they decided, why not merely ship over the new engine to South Africa?
Alas, having an entire Boeing 747 sitting on the ground in a foreign country, not earning revenue is a costly proposition, and Qantas could not afford to wait. They couldn’t send it via boat, and it was too big to fit in the cargo hold of a typical aircraft (apart from the bigger aircraft like the Antonov 225 which are expensive to hire).
Fortunately, there was a third option. Attach the new engine to the wing of the Boeing 747.
Can a Boeing 747 fly with a fifth engine?
Thanks to the design of the Boeing 747, there are anchor points under the wing to attach various objects. One of these is a spare engine. Now, this engine isn’t connected to the aircraft’s systems and can’t be used, but it is still secured and forms to the aircraft aerodynamics.
Well, kind of. The extra engine does have three significant effects.
- The aircraft is now unbalanced, with the pilots having to compensate for the skewed weight distribution.
- The extra engine adds drag to one side of the plane, and the pilots have to adjust the power on the other side to compensate.
- The special cargo means that the aircraft is heavier and that the plane would need to make additional stops. This particular trip between Sydney and Johannesburg involved a fuel stop in Perth.
Once the aircraft landed in Johannesburg, the fifth engine was detached and installed on the grounded Boeing 747. Both jets were able to fly home.
As for the broken engine, it was shipped back the slow way to Sydney.
What do you think of this story? Would you have liked to fly onboard the special 747 flight? Let us know in the comments.