There does seem to be a lot of confusion here over what a benefit in kind is. It cannot apply to a group owned aircraft, whether the group is unincorporated or a company, since in either case the members/shareholders are bearing all the costs of operating the aircraft. There is therefore no benefit to be taxed.
If the group leases the aircraft to a flying club or similar to reduce its overheads than there is a potential tax charge on normal principles, in the event that the lease income exceeds the operating costs for the year. That is unlikely in most situations. Were it to happen then having a company, with a corporation tax exemption on the first £10k of profit, might be an advantage over a group, whose members would pay tax at their individual rates on any profit from the operation. However, this scenario is so unlikely that it is probably irrelevant to most groups.
However, if you, or a company of which you are director and/or an employee seeks to run an aircraft for its business, offsetting or trying to offset the cost of doing so against gross profit of the business, then the Revenue will look at benefits in kind which you as the employee or director enjoy by having an aircraft at your disposal. Even if every flight is for business I have heard that the Revenue argue that there is a personal benefit by virtue of it enabling the pilot to retain currency on the aircraft or even simply enjoy the pleasure of flying at low cost. This then affects your personal taxation quite dramatically.