Have you noticed the 747 at Qantas Founders Museum appears to have an extra engine.
This is known as the V-Pod or 5th Pod which was used to transport a spare engine for another 747 requiring a replacement engine around the world.
Qantas used to transport replacement engines for Boeing airliners – 747 & 767. The forward fan is removed, dismantled and carried in the cargo hold while the rest of the engine is encased in what’s called the fifth pod. It makes very little difference to the handling of the aircraft and is the most practical way to transport an almost-complete engine for a quick changeover.
It was only used ‘on as needs basis’.
If you want to see this for yourself and find out more of the story visit the museum and and do the Jet tour .