VJW
Ifyou had taken the trouble to read this thread you would know that the type of A330 can't dump fuel.
From the tone of your post it is clear that you have no idea about how long it takes to get an airliner to turn around and the distance that it takes to decend and slow the aircraft for landing.
Rather than post inaccurate rubbish I would respectfully suggest that you read the whole thread before posting.
There are posts from people who clearly know less than yourself but there are also some pearls of wisdom above and it is not hard to sort them out.