So long as the (Pty) Ltd. you quote is the Air Service Licence holder, there is no problem. There is no such thing as an extended base of operation. If Base 4 (in this case) is in fact the licence holder, it can nominate the V&A as a base of operation - yes - and it will have to have total management and operational control and will issue the tickets and raise the invoice to the client. Helicopters being utilized must be included on the Operating Certificate of Base 4 unless the (Pty) Ltd has one of course! The (Pty) Ltd you refer to can conduct the marketing as a consultancy to Base 4 but be careful how the cash flows around this matter or else - in the event of an accident or a claim - you will have fun and games I can assure you. But good luck with the operation!