Both Armstrong Whitworth and the British Aircraft Corporation vigorously competed to be awarded the contract, as well as engine manufacturing Bristol-Siddeley and Rolls-Royce Ltd to power it.

Following the AW.681's termination, it was decided to purchase the American-built Lockheed Hercules as an off-the-shelf means of fulfilling the RAF's transport requirements instead.

By 1960, several major British programmes in the field of military transport aircraft had been terminated or considerably curtailed, such as the Short Belfast and the Vickers V-1000; according to author Derek Wood, these outcomes had been largely due to a lack of meaningful support from their principal customer, the Royal Air Force (RAF).

[1] One promising opportunity remaining was Operational Requirement 351, which called for a capable medium-range freighter to replace both the Blackburn Beverley and Handley Page Hastings piston-engine aircraft then in service with the RAF.

[2][3] According to Wood, the BAC.222 proposal possessed very strong long-term production prospects and represented an excellent solution to the requirement; he also noted that both Lockheed and BAC aggressively lobbied for its construction.

[5] Wood observed that there was considerable pressure within the British aircraft industry for an indigenously developed design to be favoured, which had perhaps dissuaded the government from opting for a collaborative programme with the Americans despite explorations of such arrangements.

[6] BAC also revised their designs in line with the requirement change, although Wood notes that Armstrong Whitworth had already emerged as the front runner for selection around this time.

[8] In response to the order's cancellation, Armstrong Whitworth pursued a last-minute effort, promoting the development of a non-STOL version of the HS.681, designated the HS.802.

[13] The AW.681 was to have been powered by an arrangement of four Rolls-Royce RB.142 Medway turbofan engines; these would have been combined with a series of vectored thrust nozzles mounted upon pylons underneath the wings.

[6] The combination of BLC and thrust vectoring would have provided the AW.681 with a high degree of STOL performance, which could be achieved exclusively using its Medway engines.