Sorry, you're talking double dutch now. The rate NATS pays in has everything to do with the health of the fund at any given time along with predicted liabilities. That is how NATS managed to reduce contributions when the fund was in surplus.
This surplus, with 'predicted' trends etc is what actuaries use to predict required funding. If that is not the case, then all that NATS has done before (and that you have written) is false.
If the fund was at 150% today (as a for instance), then regardless of what the markets are doing now, the underlying rate for NATS in the future (to keep/bring the fund to 100% would be less than is being promulgated at these talks).
Any deficit will be tackled by an improvement plan agreed between the Trustees and NATS and not the underlying rate. Provided that shares recover it will add to the problem but only short term.
Exactly what people on here and the intranet are saying, yet management are using the current financial markets to cast a gloomy picture over everything.
NATS
can afford to pay more than they propose under the agreement, they just don't want to.