How long is the Singapore stopover on a flight from London to Melbourne?

if you're in Flight QF10 all the way from london to melbourne then no you're not changing planes. they're likely to be picking up or dropping off passangers in singapore and re-fuelling which usually takes about an hour. some airlines dont allow people (who are continuing) to get off the aircraft but most do especially after a long flight. they get a crew in, to clean up the aircraft for the newcoming pessengers. in that case you'd be asked to leave for about an hour which really isnt a very long time to look around the airport. it's a big airport. but then if you know what you're after( as oppose to taking your time and browsing) then it's possible to just run and grab what you want. hope this helps.

I show the flight arrives at 635PM and departs at 815PM. Generally when you keep the same flight number you stay on the same plane, but that is not always the case. Dont worry, they will take care of you, if you do need to change planes. You wont have time to shop.

I guess the flight duration takes at least 9 hours.

Have a nice journey