NATS management is very quick to try to impose things on us - the latest is the minumum hold level of FL90... being trialled in the depths of winter in the depths of recession
Not as crazy an idea as you might think. The difference in fuel between 10,000 and 5000 in the hold can be 6%. So having to drag 6% less holding fuel half way round the world could make a big difference for long range operators.
Making the holding levels FL350 in some study will not change the fact that the final reserve fuel is calculated at 1500ft AAL and until something is published in the AIP the extra London holding fuel will still have to be calculated at 7000ft and carried.
Everyone in aviation knows that less fuel is burnt holding at 9000+ compared to 7000. There is no need for a study to prove that. Would it not be better to study the effect of having to carry "London Fuel" all the way from Tokyo.