Temporary import of a utility helicopter

I want to bring a lifting helicopter from the US to the UK to undertake a lifting project. It would be in the UK for no more than 2 months and would then return to the US. The helicopter cannot transport people, it is designed purely for lifting of heavy objects. It is in effect a flying crane.
Is it possible to undertake this temporary import exempt from VAT or import duty?

Not “free of charge”, but with temporary admission (needs prior authorization).
Full customs duty would in this case be payable for a 36 month admission period, if admission is only for 2 months, only 2/36 would be payable.
VAT should be refunded after re-exit.

Sounds like an ata carnet would be the most appropriate way to temporarily import this.