The HP.80 and Avro's Type 698 were chosen as the best two of the proposed designs to B.35/46, and orders for two prototypes of each were placed. It was recognised, however, that there were many unknowns associated with both designs, and an order was also placed for Vickers' design, which became the Valiant. Although not fully meeting the requirements of the specification, the Valiant design posed little risk of failure and could therefore reach service earlier. The HP.80's crescent wing was tested on a ⅓-scale glider, the HP.87, and a heavily modified Supermarine Attacker, which was given the Handley Page HP.88 designation. The HP.88 crashed on 26 August 1951 after completing only about thirty flights and little useful data was gained during its brief two months of existence. By the time the HP.88 was ready, the HP.80 wing had changed such that the former was no longer representative. The design of the HP.80 had sufficiently advanced that the loss of the HP.88 had little effect on the programme.