Rolls Royce...

[Aerophile]

any idea what engine they're testing there?  

Trent 800 for the A380?

Yep.

These scenes are rather common amongst test aircraft - if I had to fly in an airliner that looked like that I'd be rather worried.

From what I saw on the RR website, I understand the 800 engine was designed for the B777 and the 900 was for the A380.  

[DizZa]

Just looks like another 747 to me.

How many other 747s do you see with one engine significantly larger than the rest?

One.

http://www.turbokart.com/images/ge90_nacelle.jpg

http://www.air-and-space.com/19990824%2 ... ht%20l.jpg

Heheheeehehe....

[Tjw2]

I was watching something on tv about that and it said that they could shut off the other tree engines and fly on just that one