the size of the "invincible" class, combined with it being capable of operating only helicopters and v/stol fixed-wing aircraft, limited the types of aircraft it could potentially carry in the aew mission. despite the sea king's limitations in operating altitude and endurance, it remained the only feasible option from its introduction, in spite of efforts to design a platform more suitable – one such attempt came when bae undertook a private study into the use of the proposed p.1216 advanced stovl aircraft as an aew platform, with a straight form wing and podded radar system. however, this proposal would have had a span of more than 60 ft, which was deemed the upper limit for operation aboard , and thus would have been difficult to accommodate on a ship the size of .