Ohh..jet fuel doesn't ignite that well..you try and get it to burn at minus 15 or 20 degrees..its quite good at putting out fires.
I was a refueller once before you all start and I did a rescue fire course!
(it burns ferociously once it gets up to its flash point though..don't muck around if your wing ever gets started just hang everything out and max rate to any flat ground or water IMHO)