1940-1949
| Spec. | OR | Type | Designs (accepted and tendered) |
| B.1/40 | OR.78 | Twin-engine fast bomber carrying no defensive armament | de Havilland Mosquito |
| F.1/40 | Air Observation Post (AOP) | Fane F.1/40, General Aircraft GAL.47 | |
| 2/40 | OR.79 | Twin-engined trainer aircraft | Caproni Ca 311, Caproni Ca 313 |
| F.2/40 | Fighter using Whittle jet-propulsion (Metrovick) - written for Meteor - see also F.9/40 | Gloster Meteor II | |
| B.3/40 | OR.80 | High speed bomber | Blackburn B.28 |
| F.4/40 | OR.81 | High-altitude fighter - superseded by F.7/41 (q.v.) | Westland Welkin |
| N.5/40 | OR.82 | Naval 2-seat Fleet fighter | Fairey Firefly |
| B.6/40 | OR.83 | Twin-engine day/close support bomber - later renamed Blenheim V | Bristol Bisley |
| B.7/40 | OR.84 | Medium Bomber replacement for Blenheim bomber development of Beaufighter | A design by Armstrong Whitworth not taken further Bristol Beaumont accepted but not built, led to Buckingham (q.v.) |
| 8/40 | OR.85 | Ambulance Aircraft | Airspeed Oxford |
| F.9/40 | OR.86 | Fighter using Whittle jet-propulsion (Rover/Rolls-Royce) - written for Meteor - see also F.2/40 | Gloster Meteor I |
| X.10/40 | OR.87 | Troop-carrying glider capable of carrying 7 troops | General Aircraft Hotspur I; cancelled after eighteen built - redesigned Hotspur II relegated to training - see X.22/40 & X.23/40 |
| N.11/40 | OR.88 | Naval single-seat Fleet fighter powered by Napier Sabre - see also S.8/43 | Blackburn Firebrand F.I, Hawker P.1009 "Fleet Fighter" |
| S.12/40 | OR.89 | Naval catapult-launched observation/spotting flying boat - Walrus & Sea Otter replacement - superseded by S.14/44 (q.v.) | Supermarine Type 381 |
| R.13/40 | OR.90 | General-purpose flying boat | Blackburn B-40 |
| R.14/40 | OR.91 | Very long range reconnaissance flying boat - Centaurus-engined Sunderland replacement | Saunders-Roe S.41, Short Shetland |
| 15/40 | OR.92 | Conversion of Supermarine Spitfire for Photographic Development Unit | Supermarine Spitfire |
| F.16/40 | High-altitude fighter | Vickers Type 432 | |
| 17/40 | OR.94 | Very high altitude bomber - Wellington V production order | Vickers Wellington V |
| F.18/40 | OR.95 | Night fighter with turret | Gloster F.18/40 fulfilled by de Havilland Mosquito NF.II |
| F.19/40 | Low-cost emergency production fighter | Miles M.20/2 | |
| B.20/40 | "Close Army Support Bomber" with Merlin engine able to dive bomb and photo-reconnaissance | De-navalised version of Fairey Barracuda offered but specification not proceeded with. | |
| F.21/40 | OR.96 | Fighter version of Mosquito | de Havilland Mosquito F.II |
| X.22/40 | Troop-carrying training glider - Hotspur II production order | General Aircraft Hotspur II | |
| X.23/40 | Troop-carrying training glider - Hotspur II further production order | General Aircraft Hotspur II | |
| T.24/40 | Training aircraft | Airspeed A.S.50 (not built) | |
| X.25/40 | OR.98 | Troop-carrying glider capable of carrying 14 troops | Slingsby Hengist |
| X.26/40 | OR.99 | Troop-carrying glider of wooden construction capable of carrying between 24-36 fully armed troops | Airspeed Horsa |
| X.27/40 | OR.100 | Tank-carrying heavy glider capable of carrying 7-ton load | General Aircraft Hamilcar |
| E.28/40 | OR.101 | Experimental research aircraft for deck landings - cancelled 1943 | Folland Fo.115 Folland Fo.116 (ordered but not completed) |
| F.29/40 | Twin-engined night fighter | to cover the Gloster "Reaper" development of F.9/37 (cancelled May 1941) | |
| N.1/41 | OR.102 | Naval fighter | Miles M.20/4 |
| B.2/41 | Twin-engine bomber - Blenheim replacement - written for redesigned Bristol Type 162 Beaumont. Changes in requirements and availability of superior aircraft led to type no longer being needed | Bristol Buckingham (adapted for courier duties as C.1) | |
| X.3/41 | OR.104 | Emergency Tallboy-carrying conversion of Horsa for attack on Tirpitz - later cancelled when Lancaster was modified to carry Tallboy | Airspeed A.S.52 Horsa |
| F.4/41 | Spitfire with Griffon engine - written for Spitfire IV but amended to include Mk. XXI redesign. Preceded in introduction by Mk.s XII & XIV - some overlap with F.1/43 (q.v.) | Supermarine Spitfire XXI | |
| B.5/41 | OR.106 | Pressurised high-altitude bomber - evolved into B.3/42 (q.v.) | Pressurised version of the Vickers Warwick III |
| E.6/41 | OR.107 | Experimental jet fighter - DH Spider Crab | de Havilland Vampire |
| F.7/41 | OR.108 | High-altitude fighter - revised from F.4/40 (q.v.) | Vickers Type 432, Westland Welkin |
| B.8/41 | Four-engined heavy bomber - see also B.3/42 | Short S.36, Vickers Windsor | |
| T.9/41 | Four-seat radio trainer. | Percival Proctor IV | |
| F.10/41 | OR.109 | Written for Hawker Tempest | Hawker Tempest |
| B.11/41 | OR.110 | High-speed high-altitude unarmed bomber | de Havilland DH.99, Hawker P.1005, Miles M.39 |
| 12/41 | Target tug | Miles Martinet | |
| C.1/42 | OR.113 | Interim transport aircraft - cargo version of Lancaster - York I production order | Avro York I |
| N.2/42 | OR.114 | Single-seat boat fighter | Blackburn B-44 |
| B.3/42 | OR.115 | High-performance long-range bomber | Vickers Windsor |
| B.4/42 | High performance bomber (Mosquito replacement) - Cancelled | ||
| 5/42 | Glider for RAAF | De Havilland Australia DHA-G2 | |
| E.5/42 | Experimental single-engined jet fighter - later cancelled - see E.1/44 | Gloster GA.1 | |
| E.6/42 | Experimental lightweight Tempest - written for Tempest Light Fighter - refined & re-issued as F.2/43 (q.v.) | Hawker Fury - see F.2/43 | |
| F.6/42 | Single-seat fighter | Boulton Paul P.99, Boulton Paul P.100, Hawker Type P.1018, Hawker Type P.1019, Hawker Type P.1020, Folland Fo.117a, Miles M.42, Miles M.43, Miles M.44 | |
| H.7/42 | OR.117 | Torpedo bomber - Beaufighter replacement | Bristol Brigand |
| R.8/42 | OR.118 | Long-range patrol/reconnaissance flying boat - Sunderland with Hercules engines | Short Sunderland IV/Seaford |
| Q.9/42 | OR.119 | Twin engine target tug - planned production of Monitor later cancelled - see also Q.1/46 | 'Miles Monitor TT Mk.1 |
| 10/42 | "Special Rotating Wing Glider" | used to identify the Hafner Rotabuggy | |
| B.27/42 | Halifax development aircraft | Handley Page Halifax | |
| F.1/43 | OR.120 | Development of Spitfire with Griffon & laminar flow wing - see also N.5/45 | Supermarine Spiteful |
| F.2/43 | OR.121 | Written for Tempest Light Fighter | Hawker Fury; cancelled at conclusion of hostilities. |
| TX.3/43 | OR.122 | Two-seat side-by-side seating training glider | General Aircraft G.A.L.55 |
| N.4/43 | OR.113 | Carrier-based fighter - Seafire with Griffon engine | Supermarine Seafire XV |
| O.5/43 | OR.144 | Torpedo bomber - Barracuda replacement | Fairey Spearfish |
| S.6/43 | Torpedo Bomber Reconnaissance Aircraft (Cancelled) | Armstrong Whitworth A.W.53 | |
| N.7/43 | Carrier-based fighter - revised as N.22/43 (q.v.) | Hawker Sea Fury | |
| S.8/43 | OR.124 | Naval single-seat Fleet fighter capable of carrying rockets, torpedo or bombs - Firebrand powered by Centaurus - see also N.11/40 | Blackburn Firebrand TF.III |
| F.9/43 | OR.125 | Two-seat high-altitude night fighter | Westland Welkin NF.II |
| Q.10/43 | Radio-controlled Fleet Gunnery target aircraft - Queen Wasp replacement | Miles Queen Martinet | |
| S.11/43 | OR.146 | Naval carrier-borne attack/strike aircraft - later cancelled - Sturgeon also submitted to Q.1/46 & M.6/49 (q.v.) | Armstrong Whitworth A.W.54, Short Sturgeon |
| F.12/43 | OR.126 | Long-range fighter for Far East - written for Hornet | de Havilland Hornet |
| T.13/43 | OR.148 | Advanced trainer | Bristol Buckmaster |
| B.14/43 | Heavy bomber for Far East | Avro Lincoln, Handley Page H.P.65 | |
| 15/43 | OR.151 | Medium Range Civil Transport Aircraft | Handley Page Hermes |
| E.16/43 | Experimental helicopter with powered tilting hub controlled rotor with automatic collective pitch control, and torque reaction control using jet efflux. | Cierva W.9 | |
| A.17/43 | OR.145 | Army liaison and VIP transport aircraft - Messenger I production order | Miles Messenger I |
| C.18/43 | Stop-gap airliner version of Stirling | Short S.37 Stirling | |
| F.19/43 | OR.127 | Folland design to be built by English Electric | |
| 20/43 | OR.142 | Two-seat training glider suitable for ATC cadets | Slingsby Kirby Cadet TX Mk.1 |
| T.21/43 | OR.153 | Trainer version of Fairey Spearfish | Fairey Spearfish T. Mk 1 |
| N.22/43 | OR.155 | Revision of N.7/43; carrier-based fighter | Hawker Sea Fury |
| T.23/43 | OR.131 | Trainer - all-weather fully aerobatic three-seater | Percival Prentice |
| E.24/43 | Experimental jet research aircraft capable of 1,000 mph and able to reach 36,000 ft in 1 and 1/2 minutes | Miles M.52; cancelled 1946 | |
| 25/43 | Brabazon IIA - Civil Transport for European service | Airspeed Ambassador | |
| C.26/43 (26/43) | Brabazon VB - Light Civil Air Transport | De Havilland Dove | |
| B.27/43 | OR.149 | Heavy bomber - developed Halifax | Handley Page HP.66 and HP.69 - cancelled with end of war. |
| S.28/43 | OR.150 | Firebrand replacement | Blackburn B-48 YA.1/Firecrest |
| 29/43 | Airliner version of Lancaster IV - see also B.14/43 | Avro Tudor | |
| E.1/44 | OR.157 | Experimental Nene-powered jet fighter | Gloster GA.2 |
| 2/44 | Brabazon Committee Type I | Long range transatlantic airliner | Bristol Brabazon I, Miles X-15 (not built) |
| C.3/44 | Long-range general-purpose transport - York replacement | Handley Page Hastings | |
| X.4/44 | OR.160 | Tank-carrying heavy glider capable of carrying 7-ton load and returning under its own power | General Aircraft Hamilcar X |
| N.5/44 | OR.162 | Naval carrier-version of Hornet | de Havilland Sea Hornet |
| E.6/44 | OR.170 | Written for Saro SR.44 flying-boat jet fighter | Saro SR.A/1 |
| N.7/44 | OR.167 | Carrier-based fighter - navalised version of Spitfire F Mk.21 | Supermarine Seafire F Mk.45 |
| PR.8/44 | Photo-reconnaissance version of the Bristol Buckingham | Specification cancelled | |
| E.9/44 | Flying wing jet bomber/airliner | Armstrong Whitworth A.W.52 | |
| E.10/44 | OR.182 | Experimental Nene-powered jet fighter - Jet Spiteful | see N.5/45 |
| N.11/44 | OR.174 | Naval long-range carrier-based fighter with Eagle 22 piston engine capable of accepting a turboprop at a later date - RN version of F.13/44 (q.v.) - see also N.12/45 | Westland Wyvern |
| 12/44 | Medium range civil transport aircraft | Handley Page Hermes II | |
| F.13/44 | OR.194 | Long-range fighter with Eagle 22 piston engine capable of accepting a turboprop at a later date - RAF version of N.11/44 (q.v.) - see also N.12/45 | Westland Wyvern, Hawker P.1027/P.1030 |
| S.14/44 | OR.89 | Naval land-based ASR | Supermarine Seagull ASR-1 |
| N.15/44 | OR.189 | Naval carrier-version of Mosquito | de Havilland Sea Mosquito TR.33 |
| 16/44 | Stop-gap airliner version of Lancaster | Avro Lancastrian C.Mk 1 | |
| 17/44 | Medium-short haul passenger aircraft - stop-gap airliner version of Wellington | Vickers Wellington Transport Aircraft | |
| 18/44 | Brabazon Committee Type Va | Civil feederliner | Miles Marathon |
| 19/44 | Civil transport version of the Avro York C1 | Avro York | |
| 20/44 | Jet civil transport (de Havilland DH.106) | Not issued | |
| O.21/44 | Twin-Merlin engined Fairey Spearfish | Specification cancelled | |
| 22/44 | Transport aircraft - mixed passenger, freight/passenger or all-freight high-payload/short-distance - see also G.9/45 | Bristol Wayfarer/Freighter | |
| E.1/45 | OR.195 | Experimental aircraft for research into proposed tailless configuration of early DH.106 Comet airliner design | de Havilland DH.108 |
| A.2/45 | OR.176 | Army Air Observation Post (AOP) - replacement for Taylorcraft Auster AOPs | Auster A.2/45, Heston A.2/45 |
| B.3/45 | OR.199 | Two-seat twin-engine high-altitude fast jet bomber carrying no defensive armament - Mosquito replacement - revised from E.3/45 (q.v.) | English Electric Canberra B.1 - see also B.5/47 |
| B.3/45 | Experimental two-seat twin-engine high-altitude fast jet bomber carrying no defensive armament - Mosquito replacement - reissued as B.3/45 (q.v.) | English Electric Canberra | |
| A.4/45 | OR.164 | Army three-seat light communications aircraft - Leonides-powered Pioneer II later accepted 1950 | Scottish Aviation Pioneer I |
| N.5/45 | Naval carrier-borne fighter - Seafang developed to this spec. but supplanted by Nene-powered, Naval version of E.10/44 (q.v.) | Supermarine Attacker, Supermarine Seafang | |
| T.7/45 | OR.159 | Three-seat advanced trainer using turboprop engine - Harvard replacement - replaced by T.14/47 (q.v.) | Avro Athena T.1, Boulton Paul Balliol T.1 |
| TX.8/45 | OR.180 | Tandem-seat training glider for Air Training Corps | Slingsby T.24 Falcon 4 |
| C.9/45 | OR.192 | Military transport aircraft capable of carrying a 3 ton load into jungle areas - see also 22/44 | Bristol Wayfarer/Freighter |
| E.11/45 | Experimental aircraft for research into low-speed handling and high Mach number flying of tailless designs - two examples of Swallow (one low- and one high-speed) ordered - see also E.1/45 | de Havilland DH.108 | |
| N.12/45 | OR.213 | Long-range carrier-based fighter - Wyvern with Python turboprop engine - see also F.13/44 & N.11/44 | Westland Wyvern S.4 |
| C.15/45 | Long range transport aircraft | Handley Page H.P.72 | |
| GR.17/45 | OR.220 | Carrier-borne ASW | Blackburn B-54/B-88, Fairey Gannet |
| Q.19/45 | OR.204 | Mosquito target tug | de Havilland Mosquito TT.39 |
| E.20/45 | OR.221 | Experimental helicopter - see also E.34/46 | Bristol Type 171 |
| N.21/45 | OR.226 | Naval carrier-borne two-seat night fighter | de Havilland Sea Hornet NF.21 |
| Q.1/46 | OR.225 | Naval target tug | de Havilland Mosquito TT.39, Miles Monitor, Short Sturgeon TT.1, |
| 2/46 | Brabazon Committee Type I | Long range transatlantic airliner - Brabazon II (Coupled Proteus) order | Bristol Brabazon II |
| C.3/46 | Medium-range tactical transport | General Aircraft Ltd. 65 Universal Freighter | |
| N.3/46 | Naval helicopter | Cierva Air Horse | |
| E.4/46 | Experimental gyrodyne | Fairey Gyrodyne | |
| R.5/46 | OR.200 | Four engine long-range Maritime patrol bomber - Liberator GR replacement | Avro Shackleton |
| N.7/46 | OR.218 | Naval carrier-borne interceptor/fighter bomber | Hawker Sea Hawk |
| C.9/46 | All-round air transport - military version of Viking | Vickers Valetta C.Mk.1 | |
| N.11/46 | Two-seat trainer version of Sea Fury | Hawker Sea Fury T.20 | |
| B.14/46 | OR.239 | Four engine jet heavy bomber - later used as insurance against delay of aircraft submitted to B.35/46 | Short Sperrin |
| C.16/46 | Brabazon Committee Type IIB | Short-medium range turboprop airliner carrying 24-30 passengers | Armstrong Whitworth A.W.55 Apollo, Handley Page H.P.76, Handley Page H.P.77, Handley Page H.P.78, Vickers Viscount |
| E.19/46 | Experimental helicopter for crop spraying | Cierva Air Horse | |
| 22/46 | Brabazon Committee Type IV | Jet-propelled trans-atlantic mail plane/jet airliner - MoS order for two Comet prototype/production aircraft | de Havilland Comet |
| 26/46 | Brabazon Committee Type II | Short-range feederliner - Dragon Rapide replacement | de Havilland Dove |
| E.27/46 | OR.241 | Experimental aircraft for investigation into delta wing characteristics at transonic speeds | Boulton Paul P.111 |
| PR.31/46 | OR.223 | Photo Reconnaissance version of B.3/45 | English Electric Canberra PR3 |
| E.34/46 | OR.242 | Experimental helicopter - see also E.20/45 | Bristol Sycamore |
| B.35/46 | OR.229 | Four engine swept-wing jet heavy bomber with a cruising speed of 500 kt and a ceiling of at least 55,000 ft | Armstrong Whitworth A.W.56, Avro Vulcan, Bristol Type 172, de Havilland DH.111, Handley Page Victor, Short PD.1; Designs also submitted by Vickers & English Electric |
| E.38/46 | OR.243 | Experimental aircraft for investigation into the controllability and stability of swept wings at low speeds. | Hawker P.1052 |
| N.40/46 | OR.246 | Naval carrier-borne jet fighter - see also F.4/48 | de Havilland DH.110 |
| E.41/46 | Experimental swept-wing version of Attacker - evolved into Swift | Supermarine 510, Supermarine Swift | |
| R.42/46 | Marine Reconnaissance Landplane (Avro Shackleton replacement) - cancelled | Avro Shackleton | |
| F.43/46 | OR.228 | Interceptor using Rolls-Royce AJ.65 or Metrovick F.9 axial engines - superseded by F.3/48 (q.v.) | Gloster P.234, Gloster P.248, Gloster P.250, Hawker P.1054 |
| F.44/46 | OR.227 | Two-seat twin-engined night/all weather fighter | see F.24/48 & F.4/48 |
| T.1/47 | OR.238 | Two-seat trainer version of Meteor - written around Gloster's civil Meteor demonstrator G-AKPK | Gloster Meteor T.7 |
| C.2/47 | Brabazon Committee Type III | Airliner - medium-range Empire transport | Bristol Britannia, Handley Page H.P.83, Handley Page H.P.84, Handley Page H.P.85, Handley Page H.P.86 |
| F.3/47 | Fighter - Vampire with wing strengthened for carriage of underwing stores | de Havilland Vampire F.Mk.3 | |
| B.5/47 | OR.235 | Three-seat twin-engine high-altitude fast jet bomber carrying no defensive armament - Mosquito replacement - revised from B.3/45 (q.v.) to include visual bombing requirement | English Electric Canberra B.2 |
| A.6/47 | Two-seat Army Helicopter | Bristol Type 171 | |
| E.8/47 | OR.250 | Experimental one-half scale research version of Bristol Type 172 four-jet long range bomber design - later revised for reconfigured Type 176 - all subsequently cancelled | Bristol Type 174 |
| N.9/47 | OR.254 | Naval carrier-borne jet fighter/research aircraft | Supermarine Type 508, Supermarine Type 529 |
| E.10/47 | OR.252 | Experimental research jet | Fairey Delta 1 |
| T.14/47 | OR.159 | Two-seat advanced trainer using Merlin 35 - replacement for T.7/45 (q.v.) | Avro Athena T.2, Boulton Paul Balliol T.2 |
| R.2/48 | OR.231 | Reconnaissance flying boat, updated and renumbered as R.112D in 1950s but cancelled. Expected order for PD.2 suspended | Blackburn B-78, Saunders-Roe P.104/Saunders-Roe P.162, developed Short Shetland Short PD.2, Supermarine 524 |
| F.3/48 | OR.228 | Written for P.1067, replaced F.43/46 | Hawker P.1067 (Hawker Hunter), Bristol Type 177 |
| F.4/48 | OR.227 | Two-seat twin-engined night/all weather fighter - replacement for Vampire NFs | de Havilland DH.110, Gloster Javelin |
| E.6/48 | no OR | Experimental research aircraft using one-third scale version of Handley Page B.35/46 wing design | Handley Page HP.88 |
| E.7/48 | Experimental unmanned target aircraft powered by turbojet engine - Queen Martinet replacement | Government Aircraft Factory Jindivik | |
| T.8/48 | OR.260 | ab initio trainer - Tiger Moth replacement - written for Chipmunk T.10 production order | de Havilland Chipmunk T.10 |
| B.9/48 | OR.231 | Four engine jet heavy bomber - less advanced stop-gap for B.35/46 designs - written around Valiant | Vickers Valiant |
| T.12/48 | Trainer - two-seat Wyvern conversion trainer | Westland Wyvern T.3 | |
| T.13/48 | OR.249 | Trainer - multi-engine - replacement for Wellington T.Mk 10 | Vickers Varsity T.Mk 1 |
| E.15/48 | no OR | Experimental one-third scale low-speed research version of Avro's B.35/46 design | Avro 707 |
| T.16/48 | OR.257 | Trainer - Prentice replacement | Avro 714, Handley Page H.P.R.2, Percival Provost |
| B.22/48 | OR.302 | Pathfinder version of Canberra | English Electric Canberra B.5 |
| F.24/48 | OR.265 | Two-seat twin-engined night/all weather fighter - interim stop-gap for F.4/48 - Meteor NF development originally to F.44/46 (q.v.) | Armstrong Whitworth Meteor NF.11 |
| T.1/49 | OR.269 | Navigation trainer | Vickers Valetta T3 |
| T.2/49 | OR.244 | Dual-control training version of Canberra | English Electric Canberra T4 |
| M.6/49 | OR.275 | Light carrier-borne ASW - written around Short Sturgeon variant - spec derived from GR.17/45 | Short S.B.3 |
| E.10/49 | Experimental - additional order for Avro 707s including side-by-side seating conversion-trainers - these later cancelled - see also E.15/48 | Avro 707 | |
| A.13/49 | OR.281 | Army helicopter | Saro Skeeter |
| N.14/49 | NA/A.14 | Naval carrier-borne all-weather strike fighter - see also N.40/46 & F.4/48 | de Havilland Sea Vixen |
| F.15/49 | OR.277 | Jet fighter - interim Vampire replacement | de Havilland Venom |
| E.16/49 | OR.282 | Swept-wing Mach 2 research aircraft | Armstrong-Whitworth AW.58 |
| C.19/49 | Transport - Hastings C.2 order | Handley Page Hastings C.2 | |
| F.23/49 | OR.268 | Supersonic jet fighter/interceptor | English Electric Lightning |
| H.24/49 | Air ambulance helicopter (cancelled) | Fairey FB-1 Gyrodyne | |
| U.25/49 | Small low speed pilotless target aircraft and launching pad (cancelled replaced by U.120D) | ||
| 26/49 | Replacement for the de Havilland Rapide (cancelled) | Blackburn B-84, Folland Fo 134 | |
| E.27/49 | Delta wing research (Cancelled and replaced with ER.100) | Boulton Paul P.120 |
Read more about this topic: List Of Air Ministry Specifications, List of Specifications (incomplete)