i can guarantee you thet 30 mins is not long at all for severe turbulance. I remember travelling on southwest airlines from nashville to orlando ansd for the entire 3hour flt we had severe turbulance. This was before i was crew, and I thought that plane was ging to come out of the sky. With it being the hurricane and tornado season at the time, there was nowhere the pilots could go to get out of it. The pax had to hold the crew down - who were sitting on the floor ( as it was so severe they couldn't ever walk back to their seats). 30 mins is not a long time
Didn't realise that virgin 747 carried 451 pax