The 2nd paragraph of the link you posted to the IR website implies to me that as long as you are not getting a better "deal" than anyone else in the group then no BIK arises?
Failing that and subject to your insurance arrangements you could let someone trustworthy outside of your group fly the aircraft for a few hours at the same effective rate as what you pay and then you can prove to the inspector that joe public gets the same deal so there is no preferential treatment from your scheme of arrangment.
As to the form of the entity, as others have said above it shouldn't matter whether it is a company, partnership, sole trader or anything else inbetween. If tax on BIK's is payable then it doesn't matter how you go about it. Think of your local plumber who might have a partnership with the wife and lets the lads use the van or car for private use. Assuming they declare it correctly then BIK's would be payable.