How a Boeing 747 was conducting flights with five engines
In 2016, the Boeing 747 of the Australian company Qantas flew with five engines.
The plane was stuck at the airport due to engine failure. Of course, it can take off and fly to its destination with three or even two engines, but there can’t be any passengers on the plane.
The Australians did not want to fly an empty plane home: after all, this would require sending a backup side for passengers and performing two flights with no passengers.
They did not want to send a new engine across half the globe to be replaced either by a cargo plane (this is very expensive) or by sea (this takes a very long time).
Therefore, they came up with a third method. The working engine was sent on the next flight, fixing it directly on the wing of another Boeing 747! Of course, the "extra" engine wasn’t working, it just hung there. To create less aerodynamic drag, a fan was removed from it.
In this configuration, one side of the aircraft overbalanced, and even with the fan removed, it still turned to the left. Pilots had to compensate for this moment with a rudder. Also, the aircraft became heavier by 6 tons. Due to these factors, fuel consumption also increased, so they had to board a flight from Sydney to Johannesburg to refuel in Perth.
Upon arrival, the working engine was rearranged on a plane in Johannesburg, after which both sides, albeit with a delay, delivered all passengers to Sydney. The faulty engine sailed to Sydney by sea.