OR.350/Spec.MR.218.
H.S. Comet with four RB.168 jet engines.
Avro 776 with three RR Medway.
A version of the DH Trident.
A further development of the Shackleton.
Breguet Atlantic.
Versions of the Vanguard and the VC-10.
The OR and Spec. were then replaced by AST.357.
The Short P.D.69 and various versions of current UK airliners.
As AST.357 could not be in service before 1978, a quicker solution was ASR.381/MR.254 written around the Breguet Atlantic as having the minimum acceptable performance. The final contenders were the HS.801(the Nimrod) and a variant of the Trident the HS.800.
The rest is history, one could possibly conclude that BAC were not prepared to indulge in a paper-chase “organised” by the usual suspects.
Ciarain.