# List of Air Ministry specifications

This is a partial list of the British Air Ministry (AM) specifications for aircraft. A specification stemmed from an Operational Requirement, abbreviated "OR", describing what the aircraft would be used for. This in turn led to the specification itself, e.g. a two-engined fighter with four machine guns. So for example, OR.40 for a heavy bomber led to Specification B.12/36. Aircraft manufacturers would be invited to present design proposals to the ministry, following which prototypes of one or more of the proposals might be ordered for evaluation. On very rare occasions, a manufacturer would design and build an aircraft using their own money as a "private venture" (PV). This would then be offered to the ministry for evaluation. The ministry may well release a specification based on the private venture aircraft if the plane aroused interest from the RAF or the ministry due to its performance or some other combination of features.
The system of producing aircraft to a specification ran from 1920 to 1949 during which the Air Ministry was replaced by first the Ministry of Aircraft Production (MAP) in 1940 and then the Ministry of Supply (MoS) in 1946. The system was applied to commercial aircraft as well, two being the de Havilland Comet and Vickers Viscount. During the period, over 800 specifications were issued.

## Specification designations

Each specification name usually followed a pattern. A leading letter was usually present to identify the aircraft purpose. The codes used included B for "heavy bomber", e.g., B.12/36, P for "medium bomber", e.g., P.13/36, F for "fighter", e., F.10/35, and A for "army co-operation", e., A.39/34. The second part was a number identifying it in sequence and then after the slash, the year it was formulated, so in the example given above, B.12/36 signifies a specification for a heavy bomber, the twelfth specification of all types issued in 1936. Specifications were not always issued in sequence.
Admiralty specifications were identified by the letter N (Naval), e., N.21/45, and experimental specifications identified by the letter E (Experimental), e., E.28/39, with training aircraft signified by the letter T (Training), e., T.23/31, and unpowered aircraft, signified by the letter X, e., X.26/40. The letter G (General) signified a general-purpose aircraft, e.g., G.9/45, with an M (Multi-role) being applied to aircraft intended for more than one specific purpose, e.g., M.15/35.
The letter C (Cargo) was applied to military transport aircraft, e.g., C.1/42, with the letter O (Observation) used for a naval reconnaissance aircraft, e.g., O.8/38 – the letter S (Spotter) used for the more specialised role of naval spotting, i.e., observing and reporting back the fall of naval gunfire, e.g., S.38/34 – and R (Reconnaissance) for a reconnaissance type – often a flying boat, e.g., R.3/33. Special purpose aircraft would be signified by a letter Q, this being used to specify aircraft such as target-tugs, radio-controlled target drones, etc., e.g., Q.32/55.
Sometimes the purpose for which an aircraft is used in service would change from that for which the specification to which it was designed was issued, and so there are some discrepancies and inconsistencies in designation, the Royal Navy in particular liking to specify multiple roles for its aircraft in an attempt to make the best use of the necessarily limited hangar space onboard its aircraft carriers. In this case this resulted in several types designed to specifications originally intended to signify the naval Spotting role also being used for other purposes, e.g., S.15/33, resulting in the Blackburn Shark and Fairey Swordfish, the latter aircraft being primarily utilised as a torpedo bomber. Similarly S.24/37, which produced the Fairey Barracuda, again primarily designed for spotting, the dive bomber/torpedo bomber requirements being regarded as secondary when the specification was issued, but for which roles it was almost exclusively subsequently used, the original spotting requirement having been made obsolete with the introduction of radar.
In addition, some (mostly early) specifications appear to have no letter prefix at all, e.g., 1/21, the Vickers Virginia III.

## List of specifications (incomplete)

The names of the aircraft shown in the table are not necessarily those they carried when provided for evaluation as at this point an aircraft would usually be referred to as the Manufacturer X.XX/XX, e.g., the Avro B.35/46 – this is in addition to the manufacturer's own separate internal designation for the aircraft, e.g., Avro 698. With several manufacturers submitting designs to the same specification this could result in a number of different aircraft with the same X.XX/XX designation, e.g., Handley Page B.35/46, etc. Upon acceptance of the design(s) the final service names would usually be chosen by the Air Ministry when they placed a production order, in the above B.35/46 cases, where two aircraft were accepted to this specification, Vulcan and Victor respectively.
Upon entering service, in the absence of any already-planned variants a new type would initially have no mark number after the aircraft name, being simply referred to as the Manufacturer Service-name, e.g., the Avro Anson, however upon acceptance of a new variant the previous (initial) version automatically became the 'Mark I', so in the example given, the previous (first) version of the Anson retrospectively became the Avro Anson Mk I upon acceptance of an Avro Anson Mk II. Sometimes planned variants would be later cancelled leading to 'missing' mark numbers, or the extent of the changes may have justified given the new variant a completely new name, e.g., the Hawker Typhoon II subsequently becoming the Hawker Tempest, or the Avro Lancaster B.IV & B.V entering service as the Avro Lincoln. In a few cases the same aircraft ordered with differing engines would be allocated separate names for each variant, e.g., Hawker Typhoon and Hawker Tornado, or the Handley Page Hampden and Handley Page Hereford. Typographical designation of mark numbers (Mk.) varied over time and inconsistencies are common, e.g., Mark II, Mk. II, II, etc. Initially Roman numerals were used, changing to Arabic numerals post-World War II, e.g., Supermarine Spitfire Mk I to Supermarine Spitfire Mk 24.
Note 1: where possible mark numbers are given here in this list in the form that was used at the time of acceptance. Variations may be encountered due to changes in format/typographical convention.
Note 2: due to mergers and amalgamations within the UK aircraft industry sometimes the name of the manufacturer changed over time, e.g., English Electric later became part of the British Aircraft Corporation (BAC), so the English Electric Lightning then became the BAC Lightning; the British Aircraft Corporation itself and Hawker Siddeley (HS) then later merged and became British Aerospace, subsequently becoming BAe (now BAE Systems). Thus the previously mentioned Avro Vulcan was subsequently referred to as the Hawker Siddeley Vulcan; similarly, the Blackburn Buccaneer later became the Hawker Siddeley Buccaneer. Where possible, for clarity the aircraft in this list are listed under the ORIGINATING company's name or the name of the manufacturer under which it first entered production.
Specifications within the tables are listed in numerical order by year of issue; where a given number appears more than once, with one or more letter prefixes, the entries are presented in alphabetical order.

### Air Board specifications (1917–1918)

In 1917, the Air Board began to issue specifications for new aircraft on behalf of the Royal Flying Corps and Royal Navy Air Service, with separate series for the RFC and Navy.
RFC series :
| Spec | Type | Designs |
| A.1A | Single-seat fighter – Sopwith Camel replacement | Austin Osprey, Boulton & Paul Bobolink, Nieuport B.N.1, Sopwith Snipe |
| A.1C | Single-seat fighter – ABC Dragonfly engine, became RAF Type I specification. | Nieuport Nighthawk |
| A.2B | Single- or twin-engined day bomber | Airco DH.10 Amiens |
| A.3C | Heavy bomber – superseded by RAF Type V | Abandoned |
Royal Navy Air Service series :
| Spec | Type | Designs |
| N.1A | Single seat land or ship-based fighter. | Beardmore W.B.IV, Beardmore W.B.V, Mann Egerton Type H |
| N.1B | Single-seat seaplane or flying boat fighter | Blackburn N.1B, Norman Thompson N.1B, Supermarine Baby, Westland N.1B, Wight Triplane Flying Boat |
| N.1B | Single seat torpedo bomber | Blackburn Blackburd, Short Shirl |
| N.2A | Two-seat floatplane scout | Fairey N.9, Fairey N.10, Short N.2A |
| N.2B | Two-seat floatplane bomber, 600 lb (270 kg) bombload. | Fairey IIIB, Short N.2B |
| N.2C | Twin engined patrol flying boat | Norman Thompson N.2C |

### RAF specifications (1918–1920)

    Data from: The British Aircraft Specifications File
| Spec | Type | Designs |
| Type I | Fighter, ABC Dragonfly engine. | Armstrong Whitworth Ara, BAT Basilisk, Nieuport Nighthawk, Siddeley Siskin, Sopwith Snapper, Sopwith Snark |
| Type IA | Long-distance (high altitude) | BAT Bantam, Westland Wagtail |
| Type II | Two-seat fighter | Bristol Badger |
| Type III | Two-seat fighter | Austin Greyhound, Westland Weasel |
| Type IV Type VI | Twin-engined bomber | Avro 533 Manchester, Boulton Paul Bourges, de Havilland DH.11 Oxford, Sopwith Cobham |
| Type VII | Night Bomber | Nieuport London |
| Type VIII | Bomber | Avro 533 Manchester, Boulton Paul Bourges, Bristol Braemar, de Havilland DH.11 Oxford, Sopwith Cobham |
| Type IX | Medium bomber | de Havilland Okapi |
| Type XI | Heavy bomber | Siddeley Sinaia |
| Type XX | | Gloster Nightjar |
| Type XXI | Two-seat amphibian fighter | Bristol Type 35, Fairey Pintail |
| Type XXII | Single-seat carrier based torpedo bomber (re-issued 1920) | Blackburn Blackburd, Short Shirl, 'Blackburn Swift' |
| Type XXX | Flying boat | Short Cromarty, Vickers Valentia |
| Type XXXII | Prototype training seaplane | (cancelled 1918) – Short Sporting Type produced to this specification |
| Type XXXIII | Four-engined long range flying boat | Fairey N.4 |

### 1920–1929

    Data from: The British Aircraft Specifications File
| Spec | OR | Type | Designs |
| 1/20 | None | First spec. issued: spares carrier | Bristol Type 37 Tramp |
| 2/20 | | 'Interim' single-engine heavy bomber | Avro Aldershot, de Havilland DH.27 Derby |
| 3/20 | | Single-seat deck-landing torpedo-carrier – Spec. superseded by 32/22 (q.v.) | Blackburn Dart (modified), Handley Page H.P.19 Hanley |
| 4/20 | | Long-distance photographic and reconnaissance aeroplane | Boulton & Paul Bolton |
| 5/20 | | Troop Carrier Biplane | Bristol Type 56, Vickers Victoria |
| 6/20 | | Vimy Ambulance | Vickers Vimy Ambulance |
| 7/20 | | Fleet reconnaissance and fleet spotting amphibian | Supermarine Seal II |
| 8/20 | | Three-seat reconnaissance aircraft for Army/Navy | Armstrong Whitworth Tadpole, Westland Walrus |
| 9/20 | | Medium range postal monoplane | Parnall Possum, Boulton & Paul Bodmin |
| 10/20 | | Cantilever monoplane | de Havilland Doncaster |
| 11/20 | | Medium Range Military Conversion of Postal Aeroplane | Parnall Possum, Boulton & Paul Bodmin |
| 1/21 | | Long-range bomber – Vickers Vimy replacement | Vickers Virginia III |
| 2/21 | | Experimental single-seat convertible biplane/monoplane fighter/interceptor/two-seat reconnaissance-fighter aircraft – written for Bullfinch | Bristol Bullfinch |
| 3/21 | | Naval Fleet spotter/reconnaissance aircraft | Avro Bison, Blackburn Blackburn |
| 4/21 | | Small troop carrier | Vickers Vernon |
| 5/21 | | Light day bomber – Airco DH.9A replacement | Fairey Fawn |
| 6/21 | | Postal aeroplane | Westland Dreadnought |
| 7/21 | | Single-Seat Ship Fighter | Parnall Plover |
| 8/21 | | Torpedo aeroplane | Blackburn T.4 Cubaroo |
| 9/21 | | Torpedo aeroplane | Blackburn Dart production |
| 10/21 | | Corps reconnaissance aircraft | Armstrong Whitworth Wolf, Hawker Duiker |
| 11/21 | | Vimy ambulance | Vickers Vimy ambulance |
| 12/21 | | Fleet spotting flying boat | English Electric Ayr |
| 13/21 | | Cantilever Monoplane | Handley Page H.P.20 |
| 14/21 | | Felixstowe F.5 replacement | Supermarine Scylla |
| 13/21 | | Cantilever monoplane | Handley Page H.P.20 |
| 14/21 | | Boat seaplane | Supermarine Scylla |
| 15/21 | | Twin-engined bomber | Boulton & Paul P.19 |
| 16/21 | | Biplane transport | Handley Page W.8b |
| 17/21 | | Biplane transport | Handley Page Type X, de Havilland DH.34 |
| 18/21 | | Passenger transport | Handley Page HP.18 Hanley / Handley Page HP.21 Hanley, de Havilland DH.32, Vickers Type 61 Vulcan |
| 19/21 | | Two-seat reconnaissance aircraft – Bristol F.2B Fighter replacement | Short Springbok |
| 20/21 | | High-altitude fighter | cancelled |
| 21/21 | | Spotting amphibian | Supermarine Seagull II |
| 22/21 | | Reconditioned F.2b | Bristol F.2b Fighter |
| 1/22 | | Passenger Aeroplane | Vickers Type 170 Vanguard |
| 2/22 | | Amphibians for use in the Middle East | Vickers Viking V |
| 3/22 | | Two-seat fighter/reconnaissance powered by a supercharged engine – Bristol Fighter replacement | Bristol Type 84 Bloodhound |
| 4/22 | | Reconditioning of DH.10 | Airco DH.10 Amiens |
| 5/22 | | Spare wing | de Havilland DH.29 Doncaster |
| 6/22 | | Naval carrier fighter with interchangeable wheel and float undercarriages using Armstrong Siddeley Jaguar or Bristol Jupiter engine – Nieuport Nightjar replacement | Fairey Flycatcher, Parnall Plover |
| 7/22 | | Army reconnaissance aircraft | Hawker Duiker |
| 8/22 | | Corps reconnaissance aircraft | Armstrong Whitworth Wolf |
| 9/22 | | New tail unit and trial | de Havilland DH.29 Doncaster |
| 10/22 | | Metal-winged DH.9a | Airco DH.9a |
| 11/22 | | Reconditioning of DH.9a | Airco DH.9a |
| 12/22 | | Single-engined goods carrier | Vickers Type 63 Vulcan |
| 13/22 | | Reconditioning of Snipe | Sopwith Snipe |
| 14/22 | | High performance landplane | Armstrong Whitworth Siskin III |
| 15/22 | | Modifications to Hanley | Handley Page HP.19 Hanley II |
| 16/22 | | Long range torpedo bomber to carry 21 inch torpedo | Blackburn Cubaroo, Avro 557 Ava |
| 17/22 | | Amphibian floatplane | Not proceeded with |
| 18/22 | | Amphibian seaplane | Not proceeded with |
| 19/22 | | Night bombing landplane | Not proceeded with |
| 20/22 | | Coast patrol seaplane | English Electric P.5 Cork |
| 21/22 | | Twin-engined amphibian flying boat for civil operations – see also R.18/24 | Supermarine Swan |
| 22/22 | | Two-seat fighter/reconnaissance powered by a supercharged engine – Bloodhound three aircraft order – revised from 3/22 (q.v.) | Bristol Type 84 Bloodhound |
| 23/22 | | Amphibian floatplane | Not proceeded with |
| 24/22 | | Amphibian seaplane | Not proceeded with |
| 25/22 | | Single-seat night interceptor fighter | Hawker Woodcock |
| 26/22 | | Cantilever Monoplane for Civil Purposes | Not proceeded with |
| 27/22 | | Three-engined Mail Carrying Landplane | Not proceeded with |
| 28/22 | | Rebuilding and Modification of the Doncaster | De Havilland DH.29 Doncaster |
| 29/22 | | Postal Monoplane | Westland Dreadnought |
| 30/22 | | | Boulton & Paul Bugle |
| B.30/22 | | Heavy bomber – written for Bugle II production order but Sidestrand also apparently designed to this spec. | Boulton & Paul Bugle II, Boulton Paul Sidestrand |
| 31/22 | | Four-seat heavy night-bomber | Handley Page Hyderabad |
| 32/22 | | Single-seat deck-landing torpedo-carrier – Spec. supersedes 3/20 (q.v.) | Blackburn Dart II, Bristol Brandon |
| 37/22 | | Three-seat deck landing reconnaissance aircraft – Blackburn Blackburn / Avro Bison replacement | Avro Type 550, Blackburn Airedale, Hawker Hedgehog |
| 38/22 | | General purpose seaplane/landplane | Fairey IIID |
| 40/22 | | Transport aeroplane – civil airliner – larger version of de Havilland DH.34 | de Havilland Highclere |
| 41/22 | | 'Middle East type transport aeroplane' – civil airliner | Armstrong Whitworth Argosy, de Havilland Hercules |
| 43/22 | | | Vickers Vernon II |
| 44/22 | | Single-engined long-range reconnaissance seaplane – intended for round-the-World flight | Fairey Fremantle |
| 46/22 | | Three-seat fleet-spotter amphibian | Vickers Vanellus |
| 9/23 | | Superseded by 14/24 | Blackburn Iris |
| 13/23 | | | Supermarine Seagull II |
| 16/23 | None | Spotting ship-plane | Avro Bison |
| 19/23 | | Fighter/interceptor – improved Siskin III | Armstrong Whitworth Siskin IIIA |
| 21/23 | | Fleet two-seat torpedo bomber | Avro Buffalo, Blackburn Ripon, Handley Page H.P.31 Harrow |
| 23/23 | | Coastal patrol and anti-submarine flying-boat | English Electric Kingston |
| 25/23 | | Fleet two-seat torpedo bomber/bomber | Handley Page H.P.25 Hendon |
| 26/23 | | Two-seat long-range day-bomber | Bristol Berkeley, Handley Page H.P.28 Handcross, Hawker Horsley, Westland Yeovil |
| 28/23 | | Long-range bomber – Virginia production order | Vickers Virginia |
| 37/23 | | Single-engined fighter/interceptor – improved Grebe | Gloster Gamecock |
| 38/23 | | Twin-engined Night Bombing Landplane | Vickers Vimy |
| 39/23 | | Single-engined Single-Seater Racing Seaplane | Gloster II |
| 40/23 | | Single-engined Single-Seater Racing Seaplane | Supermarine S.4 |
| 41/23 | | Fitting of Handley Page Slotted Wings to the Bristol Fighter Aircraft | Bristol F.2B |
| 42/23 | | Amphibian Alighting Gear for Fairy Flycatcher I | Fairey Flycatcher |
| 43/23 | | Special Wings to Aerofoil Section of R&M 322 for Blackburn Dart | Blackburn Dart |
| 44/23 | | Light Aeroplane | De Havilland DH.53 Humming Bird |
| 45/23 | | Two-seater Fighter Reconnaissance Landplane | Vickers Venture |
| 1/24 | | Three-seat fleet reconnaissance seaplane and amphibian | Parnall Pike, Short S.6 Sturgeon, Bristol Type 87 |
| 2/24 | | Light aeroplane | Cancelled |
| 3/24 | | Single-seat high-performance landplane | Hawker Woodcock II (production) |
| 4/24 | | "Twin-Engined Home Defence Fighter" armed with two 37 mm cannons | Westland Westbury Bristol Bagshot |
| 5/24 | | Advanced landplane, convertible to a seaplane, trainer for RAF and deck-landing trainer for FAA | Cancelled, replaced by 5A/24 |
| 5A/24 | | Floatplane trainer | Vickers Vendace, Blackburn Sprat, Parnall Perch |
| 6/24 | | Single-seat fighter | Fairey Flycatcher (production) |
| 7/24 | | 'High powered single-seater fighter landplane' | Avro Avenger, Fairey Firefly I, Fairey Fox, Gloster Gorcock, Hawker Hornbill |
| 8/24 | | Army co-operation aircraft | de Havilland Dingo |
| 9/24 | | Twin engine medium day-bomber – Sidestrand II production order – see also 25/27 | Boulton Paul Sidestrand II |
| 10/24 | | Fleet spotting ship-plane | Blackburn Blackburn |
| 11/24 | | Fleet spotting ship-plane | Avro Bison II |
| 12/24 | | Long-range bomber – Virginia production order | Vickers Virginia |
| 13/24 | | Patrol flying boat | Blackburn Iris III, Short Singapore |
| 14/24 | | Three-engined boat seaplane | Blackburn Iris, Saunders Valkyrie |
| 15/24 | | Four-seat heavy night-bomber – initial production batch of Hyderabads | Handley Page Hyderabad I |
| 16/24 | | Submarine-borne reconnaissance seaplane | Parnall Peto |
| 17/24 | | Single-seat high-speed fighter landplane | Gloster Guan |
| 18/24 | | Twin-engined amphibian flying boat – military version of boat ordered to 21/22 | Supermarine Southampton |
| 19/24 | | Three-seat spotter/reconnaissance (Fleet Air Arm)/two-seat GP (Royal Air Force) aircraft with interchangeable land & float U/C and folding wings | Fairey IIIF |
| 20/24 | | All-metal monoplane flying boat | Beardmore Inverness |
| 21/24 | | Single-seat boat seaplane for storage in restricted space | Parnall Prawn |
| 22/24 | | Three-engine boat seaplane | Saunders Valkyrie |
| 23/24 | | Twin engine civil airliner | Handley Page H.P.32 Hamlet |
| 24/24 | | Conversion of Bison I to Bison Ia | Avro Bison |
| 25/24 | | Single-seater, high-speed fighter landplane | Hawker Heron |
| 26/24 | | Three-engined land-plane for duties in the Middle East | Cancelled |
| 27/24 | | Twin engine single-seat interceptor/night fighter | Boulton Paul Bittern |
| 28/24 | | Day and night fighter – Armstrong Whitworth Siskin replacement | Armstrong Whitworth Starling |
| 29/24 | | Twin-engined boat amphibian with Lynx engines (service aircraft) | Supermarine Seamew |
| 30/24 | | Two-seat reconnaissance/army co-operation aircraft | de Havilland Hyena, Short Chamois, Vickers Vespa |
| 31/24 | | Twin-engined boat amphibian with Lynx engines (civil aircraft) | Saunders Medina |
| 32/24 | | Training landplane with Lynx engines – replaced by 3/27 | Avro 504N |
| 33/24 | | Three-engined boat seaplane for civil use | Not issued |
| 34/24 | | Freight carrying landplane | Vickers Vellore, Gloucester Goodwood |
| 35/24 | | Three-engine landplane for Middle East transport | Armstrong Whitworth Argosy |
| 11/25 | | Reconnaissance flying boat | Supermarine Southampton (production) |
| 12/25 | | Two-seater fleet reconnaissance aircraft | Cancelled |
| 13/25 | | Troop carrier | Vickers Victoria III (production) |
| 14/25 | | Demonstration flight of Cierva Autogiro | Cierva C.6A |
| 17/25 | | Naval single-seater fighter of all-metal stressed-skin construction with interchangeable wheel and float U/C powered by Lynx engine | Avro 584 Avocet, Vickers Vireo |
| 20/25 | | Army co-operation aeroplane – Bristol Fighter/DH.9A replacement | Armstrong Whitworth Atlas, Bristol Boarhound |
| 23/25 | | Two-seat day-bomber, reconnaissance & coastal torpedo-bomber | Blackburn Beagle, Gloster Goring, Handley Page H.P.34 Hare, Hawker Harrier, Westland Witch |
| 24/25 | | High altitude bomber – Hawker Horsley replacement | Blackburn Beagle, Handley Page H.P.34 Hare, Vickers Vildebeest |
| 7/26 | | Twin-float high-speed monoplane seaplane for 1927 Schneider Trophy competition | Short Crusader |
| F.9/26 | None | Day and night 'zone' fighter – no design accepted and Spec. superseded by F.20/27 (q.v.) | Armstrong Whitworth Starling II, Blackburn Blackcock / Turcock, Boulton Paul Partridge, Bristol Bulldog Mk.I, Bristol Bullpup, Gloster Goldfinch, Gloster SS.18, Hawker Hawfinch, Vickers Type 141 |
| 10/26 | | Long-range bomber – Virginia production order | Vickers Virginia |
| 12/26 | | Fast two-seat day bomber of all-metal construction using Rolls-Royce F.XIB engine | Avro Antelope, Hawker Hart, Fairey Fox IIM |
| 14/26 | | Passenger flying boat | Short Calcutta |
| 21/26 | | Naval Fleet fighter – see also N.21/26 | Parnall Pipit, Vickers Type 141, Vickers Type 177 |
| N.21/26 | | Naval Fleet fighter – see also 21/26 | Armstrong Whitworth Starling II, Armstrong Whitworth A.W.16, Blackburn Blackcock/Turcock, Fairey Firefly III, Gloster Gnatsnapper, Hawker Hoopoe, Vickers Type 177 |
| O.22/26 | | Naval high-speed, two-seat, Fleet fighter/reconnaissance | Blackburn Nautilus, Fairey Fleetwing, Handley Page H.P.37F, Hawker Osprey, Short Gurnard |
| R.4/27 | | Maritime patrol flying boat | Saunders Severn |
| R.5/27 | | Reconnaissance flying boat | Blackburn Sydney |
| 8/27 | | Long-range bomber – Virginia production order | Vickers Virginia |
| F.10/27 | | Single-seat fighter armed with six machine guns | Saunders A.10 |
| B.19/27 | | Twin engine night-bomber – Virginia/Hinaidi replacement – Hendon winner but introduction delayed so runner-up (Heyford) accepted | Avro 557 Ava, Fairey Hendon, Handley Page Heyford, Vickers Type 150, Vickers Type 163, Vickers Type 195, Vickers Type 225, Bristol Type 108 |
| C.20/27 | | Transport version of Handley Page Hyderabad / Handley Page Hinaidi – Chitral/Clive | Handley Page Clive |
| F.20/27 | | 'Interception single-seat fighter' to overtake in shortest time an enemy aircraft flying at 150 mph at 20,000 ft | Armstrong Whitworth Starling II, Bristol Bulldog Mk.II, de Havilland DH.77, Fairey Firefly II, Hawker Fury, Saunders A.10, Vickers Jockey, Westland Interceptor |
| B.22/27 | | Three engine night-bomber – abandoned due to delays and replaced by B.19/27 (q.v.) | Boulton Paul P.32, de Havilland DH.72 Canberra |
| 25/27 | | Twin engine medium day-bomber – Sidestrand II production order – see also 9/24 | Boulton Paul Sidestrand II |
| 26/27 | | General purpose aircraft – D.H.9A replacement | Bristol Beaver, de Havilland Hound, Fairey Ferret, Gloster Goral, Vickers 131 Valiant, Vickers Venture, Vickers Vixen, Westland Wapiti |
| F.29/27 | | Fighter utilizing a 37 mm cannon from Coventry Ordnance Works to meet similar requirements as F.20/27 | Vickers Type 161, Westland C.O.W. Gun Fighter, Bristol Type 112 |
| 33/27 | | 'Postal Aircraft' – experimental very-long range aeroplane for world distance-record attempt | Fairey Long-range Monoplane |
| M.5/28 | | Torpedo bomber – Spec superseded by M.1/30 (q.v.) | Handley Page H.P.41 |
| R.6/28 | | Patrol/reconnaissance flying boat | Short Sarafand |
| 8/28 | | Racing seaplane for 1929 Schneider Trophy using Rolls-Royce R engine, for use by RAF High Speed Flight | Supermarine S.6 |
| 13/28 | | Long-range bomber – Virginia production order | Vickers Virginia |
| C.16/28 | | Bomber-transport capable of carrying 30 fully armed troops, or their equivalent in cargo or bombs, for a distance of 1,200 mi (1,900 km) nonstop | Gloster TC.33, Handley Page H.P.43, Vickers Type 163, Bristol Type 115, Bristol Type 116 |
| F.17/28 | | Bulldog II production order | Bristol Bulldog Mk.II |
| 21/28 | | High-speed mailplane for Imperial Airways | Boulton & Paul Mailplane, Boulton Paul P.71A |
| 1/29 | | General purpose aircraft (for production) | Westland Wapiti |
| 2/29 | | Two-seat carrier-borne torpedo-bomber (for production) | Blackburn Ripon IIA |
| 3/29 | | Troop transport aircraft | Handley Page Clive II |
| 4/29 | | Ab initio trainer – Moth with de Havilland Gipsy I order | de Havilland Gipsy Moth |
| 5/29 | | Elementary trainer (for production) | Hawker Tomtit |
| 6/29 | | General purpose landplane | Blackburn C.A.15C, Boulton & Paul P.42, Westland Limousine V |
| 7/29 | | Troop carrying aeroplane (for production) | Vickers Victoria V |
| 8/29 | | Single-seat fighter (for production) | Armstrong Whitworth Siskin IIIA |
| 9/29 | | Day bomber (for production) | Hawker Hart |
| 10/29 | | Medium day-bomber (for production) | Boulton Paul Sidestrand III |
| 11/29 | | Day and night fighter (for production) | Bristol Bulldog IIA |
| 12/29 | | Spotter reconnaissance aeroplane for the Fleet Air Arm (for production) | Fairey IIIF |
| 13/29 | | Heavy night-bomber (for production) | Handley Page Hinaidi II |
| 14/29 | | Army co-operation aircraft | Cancelled |
| 15/29 | | General purpose aircraft | Cancelled |
| 16/29 | | Experimental tailless aircraft | Westland-Hill Pterodactyl IV |
| 17/29 | | All-metal torpedo-bomber (for development and production) | Hawker Horsley |
| 18/29 | | General reconnaissance flying boat – military version of Short S.8 Calcutta | Short Rangoon |

### 1930–1939

| Spec | OR | Type | Designs |
| M.1/30 | | Torpedo bomber – Spec. supersedes M5/28 (q.v.) | Blackburn M.1/30, Handley Page H.P.46, Vickers Type 207 |
| 2/30 | | Dual control conversion set issued to Blackburn but then cancelled | |
| 3/30 | | Basic trainer – Avro 504N replacement | Avro Type 621 Trainer |
| 5/30 | | Mail carrier | Vickers Type 166 Vellore II |
| 6/30 | | ab initio trainer – Lynx-Avro (Avro 504N) production order | Avro 504N |
| F.7/30 | OR.1 | Fighter capable of at least 250 mph and armed with four machine guns | Blackburn F.3, Bristol Type 123, Bristol Type 133, Gloster Gladiator, Gloster SS.19, Hawker P.V.3, Supermarine Type 224, Westland F.7/30 |
| 8/30 | | ab initio trainer – Moth with Gypsy II order | de Havilland Moth |
| S.9/30 | | Two-seat carrier-borne torpedo bomber/three-seat spotter-reconnaissance aircraft | Fairey T.S.R.I, Gloster FS.36; see also S.15/33 |
| 16/30 | | Naval fighter – written for Nimrod | Hawker Nimrod |
| 18/30 | | Fairey IIIF replacement | Fairey Gordon I |
| 19/30 | | Naval fighter/reconnaissance with folding wings and interchangeable wheel/float U/C | Hawker Osprey |
| G.4/31 | OR.2 | General-purpose/torpedo bomber – Wapiti & Gordon replacement – Wellesley one of two designs submitted by Vickers and itself a PV – see also G.22/35 | Blackburn B-7, Bristol Type 120, Fairey G.4/31, Handley Page H.P.47, Hawker P.V.4, Parnall G.4/31, Vickers G.4/31, Vickers Wellesley, Westland PV-7 |
| 5/31 | | Long-range bomber – Virginia production order | Vickers Virginia |
| 13/31 | | ab initio trainer with complete freedom for parachute escape by both occupants – D.H.60T accepted with modifications, becoming D.H.82 – see also T.23/31 (some sources give 13/31 as an order for the Ripon IIC) | Avro Type 631 Cadet, de Havilland D.H. 60T Tiger Moth |
| 18/31 | | Basic trainer – Avro Type 621 Trainer with Lynx engine | Avro Tutor |
| R.19/31 | | Three-engined long-range reconnaissance flying boat – Rangoon three-aircraft production order | Short Rangoon |
| R.20/31 | | Twin-engined flying boat – all-metal Kestrel-engined Southampton II (Southampton IV/Scapa) | Supermarine Scapa |
| T.23/31 | | Tiger Moth I production order | de Havilland Tiger Moth I |
| R.24/31 | OR.3 | "General Purpose Open Sea Patrol Flying Boat" | Saunders Roe London, Short R.24/31 Knuckleduster, Supermarine Stranraer |
| C.26/31 | OR.4 | Bomber-transport – Valentia replacement | Armstrong Whitworth A.W.23, Bristol Bombay, Handley Page H.P.51. Supermarine Type 231 – (not built) |
| B.9/32 | OR.5 | Twin-engine medium day bomber with appreciably higher performance than predecessors – later revised to specify Goshawk power and subsequently re-revised with Goshawk requirement dropped | Vickers Wellington (renamed from 'Crecy'), Handley Page Hampden, Bristol Type 131 |
| S.11/32 | OR.6 | Naval catapult observation/spotting seaplane for carriage on cruisers | Fairey Seafox |
| T.12/32 | | Trainer | Bristol Type 124 |
| 19/32 | | Conversion of Westland Wapiti into Westland Wallace standard | Westland Wallace |
| 20/32 | | Three-engined long-range reconnaissance flying boat – improved Iris with Buzzard engines | Blackburn Perth |
| 25/32 | | Basic trainer – revised-Tutor production order | Avro Tutor I |
| B.23/32 | | Twin-engine medium bomber – written for Heyford I & IA production order | Handley Page Heyford Mk. I/IA |
| P.27/32 | OR.7 | Light day bomber – Hart/Hind replacement – see P.23/35 | Armstrong Whitworth A.W.29, Fairey Battle, Gloster P.27/32, Bristol Type 136 |
| R.1/33 | | Patrol/reconnaissance flying boat | Westland-Hill Pterodactyl Mk.VII |
| R.2/33 | OR.8 | Long-range patrol/reconnaissance flying boat | Short Sunderland, Saro A.33 |
| R.3/33 | | Long-range patrol/reconnaissance flying boat – trials order for Singapore III | Short Singapore III |
| F.5/33 | OR.9 | Twin-engine two-seat turret fighter – later cancelled | Armstrong Whitworth A.W.34, Boulton Paul P.76, Bristol Type 140, Gloster F.5/33, Parnall F.5/33, Westland-Hill Pterodactyl Mk.V |
| T.6/33 | | Tiger Moth floatplane two aircraft evaluation order | de Havilland Tiger Moth |
| 13/33 | | 4-engined mail seaplane and 4-engine flying boat carrier – Short-Mayo Composite | Short S.20 Mercury, Short S.21 Maia |
| 14/33 | | Fairey Gordon II production order | Fairey Gordon II |
| S.15/33 | OR.10 | Naval carrier-borne torpedo bomber/spotter/reconnaissance (TSR) – Fairey 9/30 (q.v.) design modified and re-submitted as T.S.R.II – Spec. replaces S.9/30 & M.1/30 (q.v.) | Blackburn Shark, Fairey Swordfish, Gloster TSR.38 |
| 18/33 | | Radio-controlled Fleet gunnery target aircraft | de Havilland Queen Bee |
| 21/33 | | Three-seat general purpose/Army co-operation aircraft – Fairey IIIF/Wapiti replacement – improved Vildebeest | Vickers Vildebeest |
| F.22/33 | OR.11 | Fighter | Bristol Type 141 |
| G.23/33 | | General purpose aeroplane – Hart for Middle East | Hawker Hardy |
| 24/33 | | Gloster Gauntlet production order | Gloster Gauntlet |
| 25/33 | | Twin-engined troop and cargo transport – improved Victoria | Vickers Valentia |
| T.26/33 | | Tiger Moth II production order | de Havilland Tiger Moth II |
| B.29/33 | | Twin engine medium day bomber with power-operated nose turret | Boulton Paul Sidestrand V (Overstrand) |
| 1/34 | | Two-seat Army Co-operation Fighter Bomber for the Royal Australian Air Force | Hawker Demon |
| 2/34 | | High-altitude research aircraft capable of reaching 50,000 ft | Bristol Type 138A |
| B.3/34 | OR.12 | Heavy bomber landplane, twin-engine night bomber & bomber/transport – Virginia, Heyford & Hendon replacement – transport requirement later removed after protests from manufacturers | Armstrong Whitworth Whitley, Bristol Type 144 |
| P.4/34 | OR.13 | Light day bomber for tactical support | Fairey P.4/34, Hawker Henley |
| F.5/34 | OR.14 | Single-seat fighter (although contracts were placed for prototypes with three companies none were ordered into production) | Bristol Type 146, Martin-Baker M.B.2, Vickers Type 279 Venom, Gloster F.5/34 |
| 6/34 | | Single-engine biplane amphibian for Australia. | Supermarine Seagull V |
| G.7/34 | | Two-seat general purpose light bomber, Interim Hart day bomber replacement | Hawker Hind |
| 8/34 | | Two-seat interceptor fighter (production of Demon I for the RAF) | Hawker Demon |
| 9/34 | | Two-seat day bomber and army co-operation aircraft (production of Hawker Audax) | Hawker Audax |
| 10/34 | | Hawker Hart communications aircraft (two aircraft delivered to No. 24 Squadron RAF) | Hawker Hart |
| 11/34 | | Torpedo spotter reconnaissance aircraft development (One Fairey Seal fitted with an Armstrong Siddeley Panther VI engine) | Fairey Seal |
| 12/34 | | Torpedo spotter reconnaissance aircraft development (production of 16 Sharks for use by No. 820 Squadron RAF) | Blackburn Shark |
| 13/34 | | Bulldog trainer production (production of Bulldog TM Type 124) | Bristol Bulldog |
| R.14/34 | | Singapore III production order | Short Singapore III |
| 15/34 | | Three-seat torpedo bomber (production of Mk III) | Vickers Vildebeest |
| 16/34 | | Three-seat general purpose aircraft – Vincent I production order including conversion of outstanding Vildebeests to Vincents | Vickers Vincent I |
| 17/34 | | Torpedo bomber (additional Baffin T.8A aircraft for conversion training, three built) | Blackburn Baffin |
| 18/34 | | Single-engine day bomber (Hawker Hart IB production) | Hawker Hart |
| 19/34 | | Two-seat Army co-operation aircraft (production of Audax Is for use in India, 50 aircraft built | Hawker Audax |
| B.20/34 | | Twin-engine night bomber – Hendon production order to this spec – see also B.19/27 | Fairey Hendon |
| 21/34 | | Two-seat fleet spotter reconnaissance aircraft (Osprey III production) | Hawker Osprey |
| 22/34 | | Close-support aircraft – Audax for SAAF | Hawker Hartebeest |
| B.23/34 | | Twin engine medium day bomber – Overstrand production order | Boulton Paul Overstrand |
| 24/34 | | Basic trainer – production order for second batch of definitive Tutor design – see 3/30, 18/31 & 25/32 | Avro Tutor I |
| 25/34 | | Amphibian trainer (production of three Clouds) | Saro Cloud |
| 26/34 | | Float seaplane trainer (production of 16 Tutors for the Seaplane Training School) | Avro Type 646 Sea Tutor |
| O.27/34 | OR.15 | Naval dive bomber | Blackburn Skua |
| B.28/34 | | Twin-engine medium bomber – written for Heyford II production order | Handley Page Heyford Mk. II |
| 29/34 | | Hawker Fury for the South African Air Force | Hawker Fury |
| 30/34 | | Twin-engined troop and cargo transport – Valentia I production order | Vickers Valentia I |
| 31/34 | | Armoured day bomber (development of armoured crew protection for the Hart) | Hawker Hart |
| 32/34 | | Navigation trainer – Prefect production order | Avro 626/Prefect |
| F.36/34 | OR.16 | High Speed Monoplane Single Seater Fighter (based on the Hawker submission to F.5/34) | Hawker Hurricane |
| F.37/34 | OR.17 | High Speed Monoplane Single Seater Fighter (based on the private venture Supermarine Type 300 submission) | Supermarine Spitfire |
| S.38/34 | | Written for Swordfish production order | Fairey Swordfish I |
| A.39/34 | OR.18 | Two-seat Army co-operation aeroplane | Bristol Type 148, Westland Lysander |
| B.1/35 | OR.19 | Twin-engine heavy bomber | Airspeed A.S.29, Boulton Paul P.79, Armstrong Whitworth A.W.39, Handley Page H.P.55, Vickers Warwick |
| 2/35 | | Naval catapult-launched observation/spotting flying boat for carriage on cruisers | Supermarine Walrus |
| F.9/35 | OR.20 | Two-seat four-gun turret fighter – Demon replacement | Hawker Hotspur, Boulton Paul Defiant, Bristol Type 147 |
| F.10/35 | | Drawn up for the Spitfire prototype | Supermarine Spitfire |
| 13/35 | | Naval torpedo-spotter-reconnaissance aircraft – written for Shark production order | Blackburn Shark |
| 14/35 | | Army Co-operation aircraft – Audax replacement | Hawker Hector |
| F.14/35 | | Written for Gladiator I initial production order | Gloster Gladiator I |
| M.15/35 | | Land-based general reconnaissance/torpedo-bomber | Blackburn Botha, Bristol Beaufort |
| 16/35 | | Autogyro – written for Cierva C.30/Avro 671 Rota evaluation order | Avro Rota |
| 18/35 | | Twin-engined coastal reconnaissance landplane – written for Anson | Avro Anson |
| 20/35 | | Radio-controlled Fleet gunnery target aircraft – Queen Bee production order | de Havilland Queen Bee |
| B.21/35 | | Twin-engine medium bomber – written for Whitley II production order | Armstrong Whitworth Whitley II |
| G.22/35 | | General-purpose day and night bomber and coastal-defence torpedo-carrier – Wellesley production order – see also G.4/31 | Vickers Wellesley |
| P.23/35 | | Written for Battle I production order | Fairey Battle I |
| G.24/35 | | General Reconnaissance – Anson replacement | Bristol Type 149, Bristol Beaufort |
| 26/35 | | Naval fighter/reconnaissance – Osprey IV production order | Hawker Osprey IV |
| B.27/35 | | Twin-engine medium bomber – written for Heyford III production order | Handley Page Heyford Mk. III |
| B.28/35 | | Drawn up for Bristol 142M | Bristol Blenheim |
| B.29/35 | | Written for Harrow initial production order | Handley Page Harrow |
| O.30/35 | | Naval turret-fighter – fighter development of Skua accepted | Blackburn Roc, Boulton Paul P.85 |
| Q.32/35 | | Radio-controlled Fleet Gunnery target aircraft – Queen Bee replacement | Airspeed Queen Wasp |
| F.34/35 | | Twin-engined turret-armed fighter | Gloster F.34/35 |
| F.35/35 | | Very high speed fighter | Airspeed A.S.31, General Aircraft GAL.28, Bristol Type 151, Hawker Hurricane variant (none built) |
| 36/35 | | Trans-Atlantic mail plane | de Havilland Albatross |
| F.37/35 | OR.31 | Fighter with cannon | Westland Whirlwind, Hawker Hurricane with Oerlikon cannon, Supermarine Type 313, Bristol Type 153 |
| 39/35 | | Twin-engine communications aircraft – Envoy with dorsal turret order for SAAF | Airspeed Envoy |
| R.1/36 | OR.32 | Small reconnaissance flying boat | Saro Lerwick, Blackburn B-20 |
| 2/36 | | Development of the Cierva C.30 (cancelled) | |
| 3/36 | | Development of the Avro 652A (cancelled) | |
| 4/36 | | Catapult bomber (cancelled) | Short S.27 |
| 5/36 | OR.33 | Improved Walrus for the Fleet Air Arm | Supermarine Walrus |
| T.6/36 | OR.34 | Advanced monoplane trainer mounting manually operated dorsal turret – Don accepted but proved unsuitable | de Havilland Don, Miles Kestrel |
| M.7/36 | | Torpedo Spotter Reconnaissance aircraft (cancelled) | Fairey Albacore |
| O.8/36 | OR.36 | Reconnaissance dive bomber for the Fleet Air Arm (cancelled) | |
| | S.9/36 | Three-seat spotter fighter for the Fleet Air Arm (cancelled) | Fairey S.9/36 |
| 10/36 | OR.38 | Written for Beaufort production order | Bristol Beaufort I |
| 11/36 | OR.39 | Interim General Reconnaissance – aircraft later renamed 'Blenheim IV' and 'Bolingbroke' name transferred to Canadian-built Blenheim | Bristol Bolingbroke I |
| B.12/36 | OR.40 | Four-engine heavy bomber 250 mph cruise, 1500 mile range, 4000 lb bomb load | Armstrong Whitworth B.12/36, Short Stirling, Supermarine Type 316 |
| P.13/36 | OR.41 | Twin-engined medium bomber for "world-wide use" introduction delayed due to production difficulties necessitating further order of Whitleys & Wellingtons | Avro Manchester (2 prototypes ordered), Handley Page H.P.56 (two prototype ordered), Hawker P.13/36 (project only), Vickers Warwick with Rolls-Royce Vulture engines. |
| 14/36 | | Production specification for the Fairey Battle I | Fairey Battle (500 ordered later reduced to 311) |
| F.15/36 | | Written for Hurricane redesigned for Merlin II | Hawker Hurricane I |
| 17/36 | | Written for Hotspur initial production order – later cancelled | Hawker Hotspur; cancelled |
| 19/36 | | Naval torpedo-spotter-reconnaissance aircraft – written for Shark additional production order | Blackburn Shark |
| B.20/36 | | Twin-engine medium bomber – written for Whitley III production order | Armstrong Whitworth Whitley III |
| T.23/36 | | Multi-role crew trainer | Airspeed Oxford |
| 25/36 | | Written for Skua initial production order | Blackburn Skua |
| 26/36 | | Written for Roc initial production order | Blackburn Roc |
| 29/36 | | Written for Wellington (revised Crecy from B.9/32) initial production order | Vickers Wellington I |
| B.30/36 | | Written for Hampden initial production order | Handley Page Hampden I |
| 33/36 | | Written for Blenheim I production order (Rootes) | Bristol Blenheim I |
| 36/36 | | Written for Lysander initial production order | Westland Lysander I |
| 37/36 | | Written for Walrus additional production order | Supermarine Walrus I |
| 39/36 | | Written for Botha additional production order (Boulton Paul) – cancelled | Blackburn Botha |
| T.40/36 | OR.44 | Development and production of a trainer version of the Miles Hawk | Miles Magister |
| S.41/36 | | Three-seat torpedo/spotter-reconnaissance aircraft – Swordfish replacement | Fairey Albacore |
| 42/36 | | Target tug – order for Henley target tug conversions by Gloster's | Hawker Henley III |
| 43/36 | | Autogyro | Cierva C.40 Rota II |
| B.44/36 | | Written for Dagger-Hampden (Hereford) production order | Handley Page Hereford I |
| 45/36 | | Written for Botha additional production order (Blackburn) – cancelled | Blackburn Botha |
| 47/36 | | Written for Bombay II production order | Bristol Bombay II |
| T.1/37 | | Basic trainer | Heston T.1/37 Trainer, Miles M.15, Parnall Heck III, Airspeed A.S.36 (not built) |
| 2/37 | | Written for Blenheim I production order (Avro) | Bristol Blenheim I |
| 6/37 | | Twin-engine VIP transport aircraft – order for The King's Flight | Airspeed Envoy |
| Q.8/37 | | Radio-controlled Fleet Gunnery target aircraft – Queen Bee replacement – role subsequently carried-on by Queen Wasp – see Q.32/35 | Airspeed A.S.37 (not built) |
| F.9/37 | OR.49 | Twin-engine day/night fighter | Gloster G.39 |
| F.11/37 | | Twin-engine two-seat day & night fighter/ground support | Boulton Paul P.92 |
| F.18/37 | | Heavily armed interceptor armed with 12 x 0.303 mgs and capable of at least 400 mph | Bristol F.18/37, Gloster F.18/37, Hawker Tornado, Hawker Typhoon, Supermarine Type 324, Supermarine Type 325 |
| 19/37 | | Written for Manchester I production order | Avro Manchester I |
| 20/37 | | Written for Roc floatplane production order | Blackburn Roc |
| S.23/37 | OR.52 | Four-engine carrier-based Fleet shadower/follower – low-speed, high-endurance, ship-tracking aircraft – requirement later rendered obsolete due to introduction of radar | Airspeed AS.39, General Aircraft GAL.38 |
| S.24/37 | OR.53 | Naval torpedo/dive-bomber, reconnaissance – Supermarine entry featured variable-incidence wing | Supermarine S.24/37, Fairey Barracuda |
| 32/37 | | Written for Halifax initial production order | Handley Page Halifax I Srs 1 – I Srs 3 |
| B.32/37 | OR.44 | Production contract for a four-engine version of the P.13/36 H.P.56 design | Handley Page H.P.57 Halifax |
| F.36/37 | | Gladiator II production order | Gloster Gladiator II |
| 37/37 | | Magister I production order | Miles Magister I |
| 38/37 | | Three-seat communications aircraft & instrument/wireless trainer | Miles Mentor |
| T.39/37 | | Three-seat communications aircraft & instrument/wireless trainer | Airspeed AS.42 Oxford for the Royal New Zealand Air Force |
| 42/37 | | Specification for wooden mockup of Miles X2 large transport aeroplane – not built – lead to Miles M.30X Minor scale testbed | Miles M.30X Minor |
| 43/37 | | Engine testbed | Folland Fo.108; designs also tendered by General Aircraft & Percival |
| S.7/38 | | Naval catapult-launched observation/spotting flying boat – Walrus replacement | Supermarine Sea Otter |
| O.8/38 | | Naval carrier-borne fighter/observation – winner developed from Fairey's earlier P.4/34 entry | Fairey Fulmar |
| B.9/38 | | Twin-engine medium bomber of simple construction using materials other than light alloy wherever possible | see B.17/38 and B.18/38 |
| 14/38 | | Long-range pressurised high-altitude monoplane transport/airliner (Shorts) – 3 prototypes ordered, construction started – cancelled | Short S.32 |
| 15/38 | | Short/Medium-range monoplane transport/airliner (Fairey) – Fairey FC.1, 14-aircraft production order – cancelled | Fairey FC1, General Aircraft GAL.40 |
| 16/38 | | Trainer – Master I production order | Miles Master T.Mk.I |
| B.17/38 | | Twin-engine medium bomber of mixed wood/metal construction | Bristol Type 155 (cancelled by Bristol) |
| B.18/38 | | Twin-engine medium bomber of mixed wood/metal construction | Armstrong Whitworth Albemarle |
| B.19/38 | | Bomber with 8,000 lb load and eight 20mm cannon in two turrets – revised to become B.1/39 | Bristol Type 157 |
| 20/38 | | Communications aircraft – Vega Gull order | Percival Vega Gull |
| 21/38 | | Communications aircraft – Dominie production order | de Havilland Dominie |
| S.22/38 | | Naval helicopter | Cierva C.41 Gyrodyne |
| 24/38 | | Twin-engine communications aircraft – Envoy production order | Airspeed Envoy |
| 25/38 | | Twin-engine communications aircraft | Percival Petrel |
| 26/38 | OR.65 | Three-seat wireless or navigation training aircraft with dual controls – Vega Gull adapted for communications training | Percival Proctor I |
| 28/38 | OR.66 | Two-seat helicopter – written for Weir W.6 | Weir W.6 |
| T.29/38 | | Twin-engine R/T (Radio Telephony) training aircraft – Dominie three aircraft order | de Havilland Dominie |
| B.1/39 | | "Ideal Bomber" four-engined heavy bomber with 9,000 lb bomb load and 20mm cannon defence (revised B.19/38) – work suspended June 1940 | Handley Page H.P.60, Bristol Type 159, a Gloster submission, Armstrong Whitworth AW.68 |
| T.4/39 | OR.68 | Single-engined trainer | Airspeed Cambridge – (two prototypes ordered, no production contract) |
| R.5/39 | | Long-range patrol flying boat – Sunderland replacement – superseded by R.14/40 (q.v.) | Saunders-Roe S.38 – later cancelled |
| N.8/39 | | Naval two-seat carrier-borne fighter – Roc replacement – replaced by N.5/40 | see N.5/40 |
| N.9/39 | | Naval two-seat carrier-borne fighter – Fulmar replacement – replaced by N.5/40 | see N.5/40 |
| F.17/39 | | Long-range fighter development of Bristol Beaufort – written for Beaufighter | Bristol Beaufighter |
| F.18/39 | | Fighter – Hurricane/Spitfire replacement | Martin-Baker M.B.3, Martin-Baker M.B.5 |
| 19/39 | | Twin-engine transport aircraft – order for Hertfordshire later cancelled | de Havilland Hertfordshire |
| 20/39 | | Twin-engine communications aircraft – order for No. XXIV Squadron RAF | de Havilland Flamingo |
| 21/39 | | Twin-engine VIP transport aircraft – order for The King's Flight | de Havilland Flamingo |
| F.22/39 | OR.76 | Fighter fitted with heavy-calibre nose-mounted gun | Vickers 414 Vickers Type 432 – also tests with Vickers Type 439 testbed – specification later cancelled |
| B.23/39 | | Very high altitude version of Wellington capable of operating at 40,000 ft | Vickers Wellington V |
| E.28/39 | | Experimental aircraft using Whittle jet-propulsion with provision for 4 × 0.303 machine guns | Gloster E.28/39 |

### 1940–1949

| Spec | OR | Type | Designs |
| 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 reconnaissance/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 photoreconnaissance | 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 and 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 a.k.a. "Thin-Wing Typhoon" | 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 |
| 11/42 | | "Special Rotating Wing Glider" | used to identify the Hafner Rotachute |
| F.1/43 | OR.120 | Development of Spitfire with Griffon & laminar flow wing. | 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-11 (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 | | Photoreconnaissance 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 | RAF (land) variant of Nene-powered jet fighter prototype | Supermarine Attacker |
| 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 C.9/45 | Bristol Wayfarer/Freighter |
| E.1/45 | OR.195 | Naval variant of Nene-powered jet fighter prototype | Supermarine Attacker (Royal Navy) |
| 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 variant of Supermarine Spiteful | 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 |
| F.11/45 | | Naval jet fighter – DH Vampire for sea trials – cancelled | de Havilland Vampire Mk X |
| 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.13/45 | | High speed military transport aircraft | Airspeed Ayrshire |
| GR.14/45 | | Maritime reconnaissance aircraft – Vickers project, cancelled. | |
| C.15/45 | | Long range transport aircraft | Handley Page H.P.72 |
| N.16/45 | | Twin-engined strike aircraft – Three aircraft ordered from Fairey but not built. | Fairey N.16/45, |
| GR.17/45 | OR.220 | Carrier-borne ASW | Blackburn B-54/B-88, Fairey Gannet |
| E.18/45 | OR.207 | Experimental aircraft – Single-engine jet aircraft for use as an aerodynamic testbed for tail less design. | De Havilland DH.108 |
| 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 |
| E.6/46 | OR.216 | Experimental long range aircraft – variant of the Avio Lincoln | Avro 689 |
| 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 medium 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 |
| X.30/46 | | Assault glider | Shorts S.48 / S.A.9 |
| 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 medium 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 MR.III replacement) – cancelled | Avro Shackleton MR.IV |
| F.43/46 | OR.228 | Interceptor with 4.5 inch recoilless gun 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, Supermarine Type 508 variant |
| 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 |
| E.1/48 | | Small Jet Propelled Helicopter (not-built) | Isacco Helicogyre No. 5 |
| 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. 630 mph at 45,000 ft in 6 minutes. Single Avon or Sapphire engine, armed with two or four 30 mm Aden cannon. | Hawker P.1067 (Hawker Hunter), Bristol Type 177, Gloster P.275, Supermarine Type 526 |
| F.4/48 | OR.227 | Two-seat twin-engined night/all weather fighter – replacement for Vampire NFs | de Havilland DH.110, Gloster Javelin |
| 5/48 | | Long Range Empire Aircraft (cancelled) | Avro 709, Blackburn B-73, Fairey FC.4 |
| 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 medium bomber – less advanced stop-gap for B.35/46 designs – written around Valiant | Vickers Valiant |
| 10/48 | | Twin-engine crop sprayer (cancelled) | Cierva W.11T |
| 11/48 | | Production of Avro Tudor IVB civil aircraft (cancelled) | |
| 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 |
| S.14/48 | NAR.21, OR.264 | Naval version of the Sikorsky S-51 | Westland Dragonfly |
| 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, Boulton Paul P.115, Boulton Paul P.116 |
| T.17/48 | OR.260 | Primary Elementary Trainer | Fairey Primer |
| 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 / AI trainer | Vickers Type 743 Valetta T.3 |
| T.2/49 | OR.244 | Dual-control training version of Canberra | English Electric Canberra T.4 |
| T.3/49 | | Flying classroom | Avro Anson – cancelled |
| E.4/49 | | Experimental aircraft for B.9/48 | Vickers Type 663 Tay Viscount |
| F.5/49 | | Long range fighter for RAF | |
| M.6/49 | OR.275 / NRA/9 | Light carrier-borne ASW – written around Short Sturgeon variant – spec derived from GR.17/45 | Short S.B.3 |
| 7/49 | | not issued | |
| N.8/49 | NRA/18 | Naval strike aircraft | de Havilland DH.109 cancelled |
| A.9/49 | OR.274 | Army / RAF evacuation helicopter | Bristol Sycamore HC.10 & Bristol Sycamore HC.11 prototypes |
| 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 |
| E.11/49 | | Experimental – flying shell of B.35/46 | cancelled |
| 12/49P | | Proposed production of B.5/47 by English Electric | cancelled |
| A.13/49 | OR.281 | Army helicopter | Saunders-Roe 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 |
| T.17/49 | NR/A20 & OR.283 | Crew trainer for Royal Navy / FAA | Percival Sea Prince T.1 |
| C.18/49 | NR/A15 & OR.283 | Communication aircraft | Percival Sea Prince C.1 |
| 19/49P | | Transport – Hastings C.2 order | Handley Page Hastings C.2 |
| A.20/49 | OR.270 | Air observation post aircraft | Auster AOP.9, Percival O.68 and Percival P.69 tendered |
| A.20/49 Issue 2 | | Production Auster AOP.9 | Auster AOP.9 |
| 21/49 | | Medium range passenger transport | Vickers VC.2 Type 630 Viscount |
| U.22/49 | | high speed pilotless target aircraft and launching ramp | GAF Jindivik II – cancelled |
| F.23/49 | OR.268 | Supersonic jet fighter/interceptor | English Electric P.1 & English Electric P.1A |
| F.23/49 Issue 2 | OR.268 Issue 1 | Three prototype supersonic jet fighter/interceptor aircraft | English Electric P.1B Lightning |
| F.23/49 Issue 3 | OR.268 Issue 4 | Three prototype supersonic jet fighter/interceptor aircraft | English Electric P.1B Lightning |
| F.23/49 Issue 4 | OR.268 Issue 6 | 20 pre-production supersonic jet fighter/interceptor aircraft | English Electric P.1B Lightning |
| F.23/49 Issue 5 | | outline Specification for proposed German version | English Electric P.1B Lightning |
| 23/49P | OR.268 Issue 6 | Fifty production supersonic jet fighter/interceptor aircraft | English Electric Lightning F.1 & English Electric Lightning F.1A |
| 23/49P.2 | OR.268 Issue 6 | Forty two production supersonic jet fighter/interceptor aircraft | English Electric Lightning F.2 |
| 23/49P.3 | | Forty seven production supersonic jet fighter/interceptor aircraft + 3 prototypes converted from a pre-prod a/c and two F.2s | English Electric Lightning F.3 |
| 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 | | Configuration Research for F.23/49 (Cancelled and replaced with ER.100) | Short SB.5 |
| F.28/49 | | Development of E.38/46 (P.1052) for Australian government. | Hawker P.1052 |

## Post 1949 specifications. Air Staff Operational Requirements/targets

| Spec | OR | Year | Type | Related aircraft |
| ER.100 | | 1950 | Experimental low-speed research aircraft with highly-swept wings in support of F23/49 (i.e. English Electric P.1) | Short SB.5 |
| M.101 | NA.28 | 1950, 1952 | Three-seat anti-submarine aircraft | Fairey Firefly AS.7 |
| N102 | | 1950 | Two-seat trainer for Royal Navy | Boulton Paul Sea Balliol |
| ER.103 | | 1950 | Delta-wing research aircraft capable of Mach 1.5 | Fairey Delta 2 |
| B.104 | OR.285 | 1950 | Low-level, medium-range Pathfinder aircraft for Bomber Command | Vickers Valiant B.2 |
| F.105D | OR.288/2 | 1951 | Swept wing day-fighter development of E41/46 (qv.) for RAF | Supermarine Swift |
| F.105D2 | | | High performance derivative of Supermarine Swift | Supermarine Type 545 |
| F.105P2 | OR.288/3 | 1951 | Production of Supermarine Swift Marks 1–4 | Supermarine Swift |
| N.105D&P | NA.34 | 1952 | Navalised version of Supermarine Swift | Supermarine Type 548 |
| FR.105D&P | OR.308 | 1952 | Fighter-reconnaissance version of Supermarine Swift | Supermarine Swift FR.5 |
| PR.105D&P | OR.310 | 1952 | Medium/high-altitude reconnaissance version of Supermarine Swift | Supermarine Swift PR.6 |
| F.105D&P3 | | 1953 | Supermarine Swift armed with Fairey Fireflash air-to-air missiles | Supermarine Swift F.7 |
| H.106 | | 1951 | General purpose helicopter – update of E.34/46 (qv.) | Bristol Sycamore Mark 3 |
| A.106P | | 1951 | Production of Sycamore helicopter for Army | Bristol Sycamore HC.11 |
| HR.106P – HR.106P5 | OR.304 | 1952–53 | Air-sea rescue helicopters for RAF and RAAF | Bristol Sycamore HR.12, HR.50, HR.13, HR.51, HR.14 |
| N.107 | NA.30 | 1951 | Naval all-weather fighter | de Havilland Sea Venom |
| F.108 | OR.265/2 | 1951 | Night fighter for RAF | de Havilland Venom NF.2 |
| UB.109 | AST.1097 | 1951–1953 | Expendable Bomber (i.e., guided missile) | Bristol Type 182, Vickers Type 655, Boulton Paul P123 |
| ER.110T | | 1951 | Variable sweepback research monoplane | Armstrong Whitworth AW.59, Blackburn B.90, Boulton Paul P.121, Bristol Type 183, Saro P.149 |
| F.111P | OR.265 | 1951 | Interim jet-powered night fighter for RAF | de Havilland Vampire NF.10 |
| T.111P | | 1952 | Two-seat trainer version of de Havilland Vampire | de Havilland Vampire T.11 |
| T.111P2 | NA.36 | 1952 | Two seat Vampire Trainer for RN | de Havilland Sea Vampire T.22 |
| R.112D | OR.231/3 | | Reconnaissance flying boat | Short PD.3 |
| N.113D&P | NA.17 | 1951–1953 | Supermarine N.9/47 Development and Production | Supermarine Type 544 Scimitar F.1 |
| N.114T | NA.14 | 1951 | All-weather Naval Fighter | Armstrong Whitworth AW.165, Blackburn B.89, Fairey N.114T, Saro P.148, Short PD.5, Westland N.114T |
| C.115P | OR.266/2 | 1951 | VIP version of Handley Page Hastings | Handley Page Hastings C.4 |
| T.116D | OR.278 | 1951 | Trainer version of de Havilland DH.110 for RAF | |
| F118D, F118P | | c. 1953 | All-weather fighter | "Super Javelin" Gloster Javelin with new wing. Gloster GA.6/P.356 |
| F.119D | | 1952 | Hawker Hunter derivative with reheated Rolls-Royce Avon RA.14R and increased wingsweep | Hawker P.1083 |
| U.120D | | 1951 | Remotely piloted target aircraft | ML U.120 |
| C.121P | OR.300 | 1952 | Communication aircraft for RAF | Percival Pembroke C.1 |
| ID.122D&P | | 1953 | Intruder version of Canberra bomber | English Electric Canberra B(I)8 |
| PR.122P | | 1954 | High-altitude reconnaissance version of Canberra | English Electric Canberra PR.9 |
| M.123 | NA.32 | 1954 | Light carrier-based anti submarine aircraft | Short Seamew |
| F.124T | OR.301 | 1952 | Rocket fighter – superseded by F.137D and F.138D for Avro and Saro designs | Avro 720, Blackburn B.97, Boulton Paul P.122, Bristol Type 178, Fairey F.124T, Hawker P.1089, Saro P.154, Short PD.7, Westland F.124T |
| EH.125 | | 1952 | Experimental rotor-blade tip-jet powered helicopter | Percival P.74 |
| B.126T | OR.314 | 1952 | Low-level bomber – cancelled 1954 | Avro 721, Bristol 186, Handley Page H.P.99, Short PD.9. |
| H.127 | NA.37 | 1952 | | Westland-Sikorsky WS-55 |
| HCC.127 | | 1958 | Whirlwind helicopter for Queens Flight | Westland Whirlwind HCC 8 |
| B.128P | OR.229/3 | 1952 | Production of Victor B.1 bomber | Handley Page Victor B.1 |
| B.128P2 | | 1958 | Improved version of Victor bomber | Handley Page Victor B.2 |
| B.129P | | 1952 | Production of Vulcan B.1 | Avro Vulcan B.1 |
| B.129P2 | | 1958 | Improved version of Avro Vulcan | Avro Vulcan B.2 |
| T.130D&P | | 1952 | Conversion of unsold Handley Page Marathon airliners to navigation trainers for RAF | Handley Page Marathon T.11 |
| N.131T | | 1952 | All weather fighter for Royal Navy – no further action | de Havilland DH.116 |
| C.132 | OR.315 | 1952 | Long-range jet transport | Vickers V.1000 |
| ER.133 | | | Rocket-powered research aircraft – not issued | Bristol Type 178 |
| ER.134D | | 1954 | High-speed research aircraft | Bristol Type 188 |
| F.137D | OR.301/2 | 1953 | Rocket powered interceptor – written around Avro 720 | Avro 720 |
| F.138D | OR.301/2 | 1953 | Mixed rocket-jet interception fighter – written around SR.53 | Saunders-Roe SR.53 |
| F.139 | NA.38/3 | 1954 | Two-seat naval all-weather fighter | de Havilland Sea Vixen FAW.1 |
| D.140P | | 1953 | Pilotless target conversion of Fairey Firefly | Fairey Firefly U.8 |
| | OR.323 | 1953 | Transport aircraft – Hastings and Valetta replacement. Vickers 799 selected but requirement superseded by C.195/OR.344 (q.v.) written around Armstrong Whitworth AW.650 Argosy | Armstrong Whitworth AW.55 and AW.56, Aviation Trader ATL-95, Blackburn B-104, Bristol Type 179, Vickers Type 799 |
| RH.142D | OR.334 | 1953 | VTOL transport aircraft | Fairey Rotodyne; later cancelled |
| ER.143 | | 1953 | Experimental direct jet-lift VTOL research aircraft | Short SC.1 |
| HR.144 | OR.31934408 | 1953 | Ultra Light Helicopter | Fairey ULH |
| HR.146D&P | NA.43 | 1953 | Development of Bristol 173 for the Royal Navy. Cancelled in favour of Westland Wessex. | Bristol Type 191 for the Royal Navy |
| T147T | OR.318 | | Advanced jet trainer – not progressed | Avro Type 725 |
| M.148 | NA.39 | 1954 | Low level naval strike aircraft | Blackburn Buccaneer S.1, Armstrong Whitworth AW.168, Fairey M.148T, Hawker P.1108, Short PD.13, Westland M.148T |
| HR.149D&P | ASR.326 | 1955 | Anti-submarine development of the Bristol 173 for RAF (and later Royal Canadian Air Force). | Bristol Type 191 |
| H.150D&P | OR.325 | Twin-rotor transport helicopter for RAF | Development of the Bristol 191 for the Royal Air Force | Bristol Type 192 as the Westland Belvedere HC.1 |
| C.151 | | | Communications aircraft | de Havilland Heron C.2 and C.3 |
| F.153D | | 1955 | All weather fighter (Javelin development) | "Thin Wing Gloster All Weather Fighter". Updating of F.118. Gloster P.376 |
| AEW.154 | NA.64 | 1955 | Carrier-based Airborne Early Warning aircraft | Fairey Gannet AEW.3 |
| F.155T | OR.329 | 1955 | High-altitude fighter – Fairey Delta III selected but project cancelled in 1957 | Armstrong Whitworth AW.169, de Havilland DH.117, English Electric P.8, Fairey Delta III, Hawker P.1103, Saro P.187, Vickers Type 559 |
| R.156T | OR.330 | 1954 | High-altitude supersonic reconnaissance aircraft | Avro 730, English Electric P.10, Handley Page HP.100, Short PD.12, Vickers SP.4 |
| RB.156T | OR.330/2 | 1956 | Reconnaissance-bomber – development of R.156T – cancelled 1957 | Avro 730 |
| T.157D&P | | 1955 | Two-seat trainer version of Hawker Hunter for RAF | Hawker Hunter T.7 |
| N.157D&P | | 1957 | Two-seat trainer version of Hawker Hunter for Royal Navy | Hawker Hunter T.8 |
| C.159P | | 1955 | Purchase of single example of Bristol Freighter for A&AEE | Bristol Freighter Mk. 31 |
| ER.161 | | 1955 | Research aircraft for narrow delta wings | Armstrong Whitworth AW.171 (VTOL with lift jets), Armstrong Whitworth AW.172 (no lift jets, thin wings) |
| F.162D | | 1955 | Light jet fighter for RAF – development of Folland Midge | Folland Gnat F.1 |
| H.163 | | 1955 | Light helicopter for AOP duties for Army and training for RAF | Saunders-Roe Skeeter AOP.10, T.11, AOP.12, T.13 |
| ER.163 | | 195? | Experimental Fairey Delta 2 with de Havilland Gyron engine – later cancelled | Fairey Delta 2 |
| FR.164D&P | | 1958 | Fighter-reconnaissance version of Hawker Hunter | Hawker Hunter FR.10 |
| R.165D | | | Specification for radios and radar for de Havilland Comet C.2. Not proceeded with. | Possibly related to de Havilland Comet 2R ELINT aircraft |
| ER.166D | | 1955 | Jet-propelled lift-fan VTOL research aircraft – not proceeded with | Boulton Paul P.132 |
| F.167D | | | Hawker Hunter with AI.20 radar and de Havilland Firestreak air-to-air missiles. One aircraft (Hawker P.1109B) built | Hawker Hunter |
| D.168D&P | | 1955 | Conversion of Fairey Firefly AS.4 and AS.5 to pilotless target drone | Fairey Firefly U.9 |
| D.169D&P | | 1955 | Conversion of Canberra B2 to pilotless target drone | English Electric Canberra U.10, U.14 |
| HAS.170D&P | NA.43 | 1956 | Anti-submarine helicopter for Royal Navy | Westland Wessex HAS.1 |
| D.171D&P | | 1955 | Conversion of Avro Lincoln to pilotless target drone – Only two aircraft converted | Avro Lincoln U.5 |
| F.172D | | | Lightweight supersonic fighter – variant of Folland Gnat with thin wing, afterburning engine and air-to-air missiles. Unbuilt | Folland Gnat F.2 |
| D.173D&P | | | Conversion of Gloster Meteor F.4 to pilotless target drones by Flight Refuelling Ltd | Gloster Meteor U.15 |
| D.174D&P | | 1956 | Conversion of Gloster Meteor F.8 to pilotless target drones by Flight Refuelling Ltd | Gloster Meteor U.16 |
| ER.175 | | | Proposed conversion of de Havilland Canada DHC-3 Otter with jet flaps. Unbuilt | |
| C.176 | | 1956 | Long range transport aircraft for RAF – military version of Bristol Britannia airliner | Bristol Britannia C.1 |
| F.177D | OR.337 / NA.47 | 1956 | Mixed power (rocket and turbojet) interceptor for RAF and Royal Navy | Saunders-Roe SR.177 |
| T.178D&P | | 1957 | Dual control trainer version of English Electric Lightning | English Electric Lightning T.4 |
| TT.179D | | | Target-tug conversion of Meteor night fighter for RAF. Not proceeded with, but similar conversions made for RN as TT.20 | Gloster Meteor TT.20 |
| ER.180D | | 1956 | Sub-scale model of Avro 730 high-altitude reconnaissance-bomber to aid in development. Cancelled in 1957 with Avro 730 | Avro 731 |
| ER.181T | | | Proposed high-speed (Mach 4–5) research aircraft. Not proceeded with. | |
| T.182D | | | Proposed conversion of English Electric Canberra B.2 to radar trainer. Unbuilt. | |
| ER.183D | | | Proposed conversion by Handley Page of Jet Provost trainer for boundary layer control research. Unbuilt | Handley Page HP.103 |
| ER.184D | | 1957 | Conversion by Marshall's of Cambridge of Auster T.7 to boundary layer control research aircraft. One aircraft converted. | Marshalls MA.4 |
| T.185D | | 1958 | Two seat trainer version of Folland Gnat for RAF. | Folland Gnat T.1 |
| C.186P | | 1957 | Twin-engined STOL transport for RAF | Scottish Aviation Twin Pioneer |
| D.187D&P | | | Proposed conversion of Gloster Meteor NF.11 to pilotless target drone. Unbuilt. | |
| ER.189D | | 1959 | Purpose-built research aircraft for blown flaps. One example built. | Hunting H.126 |
| CC.190D | | | Evaluation of Edgar Percival EP.9 for Army Air Corps. Two tested, but no further purchases. | Edgar Percival EP.9 |
| HAS.191D | | 1958 | Fairey Ultra Light Weight helicopter (see HR.144D) for anti-submarine and communications use from small ships. Two evaluated. No production. |
| RB.192D | GOR.339 / OR.343 | 1957 | STOL Tactical-Strike/Reconnaissance aircraft capable of Mach 2 and suitable for operation from unpaved strips – Canberra replacement. TSR.2 selected. | Avro 738, Bristol Type 204, English Electric P.17A, Vickers Type 571, BAC TSR.2 |
| ER.193D | | 1959 | Conversion of Fairey Delta 2 with new Ogee delta wing. Specification developed into ER.221 (q.v.) | BAC.221 |
| HAS.194D | | 1959 | Small shipboard anti-submarine helicopter | Saunders-Roe P.531 |
| C.195 | OR.344 | 1959 | Replacement for Hastings and Valetta. Requirement replaced OR.323 (q.v.) and written around military derivative of Armstrong Whitworth AW.650 Argosy. | Armstrong Whitworth AW.660 Argosy |
| X.197T | | 1959 | Research glider with slender delta wing – abandoned in favour of powered ER.197D (q.v.). | Avro 759, Bristol Type 215, Fairey X.197, Handley Page HP.115, Slingsby Sailplanes T.48, Supermarine Type 573, Miles M.110 |
| ER.197D | | 1959 | Powered research aircraft for low speed handling of narrow delta wings. | Handley Page HP.115 |
| UB.198 | | 1959 | Nuclear armed air-to surface missile for V-bombers | Avro Blue Steel |
| D.199D&P | | | Proposed conversion of English Electric Canberra B2 to U.14 pilotless drones. Unbuilt. |
| UB.200D | OR.1159 | | Long range nuclear armed guided bomb. Ramjet powered derivative of Blue Steel missile. Cancelled December 1959. | Avro Blue Steel Phase 2 |
| H.201 | | 1960 | Version of Saunders-Roe P.531 for Army Air Corps | Westland Scout AH.1 |
| D.202D&P | | 1959 | Pilotless target drone | GAF Jindivik |
| C.203 | ASR.371 | 1959 | Long-range strategic transport | Avro Type 756, Hawker P.1131, Handley Page HP.111, Short Belfast, Vickers VC10 Military Freighter |
| ER.204D | | 1960 | Experimental VTOL aircraft using Bristol Pegasus | Hawker P.1127 |
| T.205D&P | | 1960 | Two seat trainer version of English Electric Lightning | English Electric Lightning T.5 |
| ER.206 | OR.346 | 1959 | Variable-sweep wing research aircraft, closely aligned with OR.346 for a strike aircraft for RAF and RN. Not developed. | BAC/Type 588, Vickers ER.206, Vickers Type 583 |
| CC.207D&6 | OR.342 | 1960 | Purchase of de Havilland Canada Beaver for Army Air Corps | de Havilland Canada Beaver AL.1 |
| D.208D&P | | 1960 | Developed version of Jindivik target drone | GAF Jindivik 102 |
| D.209D&P | | 1960 | Conversion of Gloster Meteor F.8 to pilotless target drones by Flight Refuelling Ltd. Similar to U.16 | Gloster Meteor U.21 |
| RH.210 | | 1960 | Enlarged, Rolls-Royce Tyne-powered, military transport version of Fairey Rotodyne gyroplane. | Fairey Rotodyne Z |
| HAS.211T | | 1960 | Initial tender for improved version of Westland Wessex for Royal Navy. Specification developed fully in HAS.227.D&P. | Westland Wessex HAS.3 |
| C.212D&P | | 1960 | de Havilland Comet Mk.4 transport for RAF | de Havilland Comet C.4 |
| C.213D&P | | 1961 | Vickers VC10 transport for RAF | Vickers VC10 C.1 |
| GAR.214D | OR.345 | 1960 | Tactical ground attack and reconnaissance aircraft. Specification issued to Hawker Siddeley. Abandoned by 1963 | |
| UT.215D&P | | 1962 | Training round for Blue Steel without engine or warhead, to be carried by V-bombers for training flights. Unbuilt. |
| HAS.216 | | 1961 | Small shipboard anti-submarine helicopter. Production version of Saro P.531 | Westland Wasp |
| ER.217 | | | Ground effect research machine to be built by Folland Aircraft. Not progressed. | |
| MR.218D | OR.350 | | Maritime patrol aircraft for RAF. Avro Shackleton replacement. Superseded by MR.281/OR.357. | |
| C.219D&P | | 1963 | VIP transport aircraft – modified Hawker Siddeley HS.748 airliner | Hawker Siddeley Andover |
| | OR.303 | 195? | Lightweight fighter to intercept Soviet Tupolev Tu-4 bombers | Folland Midge |
| FGA.236 | GOR.345 | 195? | V/STOL combat aircraft version of Hawker P.1127 – Harrier development | Hawker Siddeley Kestrel FGA.1 |
| | OR.350 | 18 July 1960 | Maritime patrol aircraft to enter service by 1968 | Nimrod MR.1 |
| | OR.351 | 1960 | V/STOL freighter (to NATO Basic Military Requirement NMBR.4) | English Electric P.36 |
| | OR.356 | 19?? | Supersonic V/STOL – Spec. SR.250 | Hawker Siddeley P.1154; later cancelled |
| | OR.357 | 19?? | Maritime reconnaissance aircraft – led to Nimrod | Hawker Siddeley Nimrod |
| | OR.362 | 19?? | Supersonic trainer aircraft – led to Jaguar | SEPECAT Jaguar |
| | ASR.365 | 196? | Helicopter – Tactical Support | Westland Puma |
| | ASR.367 | 196? | Bomber – Vulcan B.2 – see also B.35/46 | Avro Vulcan B.2 |
| | ASR.368 | 196? | Bomber – Victor B.2 – see also B.35/46 | Handley Page Victor B.2 |
| | ASR.372 | 196? | Trainer version of Lightning – Lightning T.5 | English Electric Lightning T.5 |
| | ASR.373 | 196? | VIP Transport aircraft – Andover CC.2 | Hawker Siddeley Andover CC.2 |
| | ASR.376 | 196? | Tanker aircraft | Handley Page Victor B(K).1 / Handley Page Victor B(K).1A |
| C.239 | ASR.378 | 196? | Transport aircraft – VC10 | Vickers VC10 |
| | ASR.381 | 196? | Interim Maritime Patrol aircraft to Spec. MR.254 – written around Atlantique | Breguet Atlantique |
| | ASR.382 | 196? | Two-seat trainer version of P.1154 for RAF – cancelled | Hawker Siddeley P.1154 |
| | ASR.384 | 196? | Harrier requirement – see also GOR.345 | Hawker Siddeley Harrier |
| | ASR.385 | 196? | Phantom for RAF | McDonnell Douglas F-4M Phantom II |
| | ASR.397 | 1970 | Basic jet trainer – BAC Jet Provost replacement | BAE Systems Hawk T.1 |
| | ASR.400 | | Airborne Early Warning Aircraft | Hawker Siddeley Nimrod AEW.3 |
| | ASR.409 | | Harrier replacement | BAe/McDonnell Douglas AV-8B Harrier GR.5 |
| T.301 | AST.412 | | Jet Provost replacement | Short Tucano T.1 |
| | GOR.2 | 1959 | VTOL Strike Reconnaissance aircraft | English Electric P.31, Gloster P.505 |

## Naval requirement/Aircraft, Naval Staff requirements

| Spec | Req. | Year | Type | Related aircraft |
| U.25/49 | NA.03 | | Small Pilotless Target Aircraft | |
| N.12/45 | NA.07 | | Single Seat, Long Range, Naval Fighter Aircraft | Westland Wyvern TF.2 |
| N.114T | NA.14 | | 2-seat all-weather day/night fighter | |
| N.9/47 | NA.17 | 16/09/47 | Naval Fighter Aircraft | Supermarine Type 508, 525 and 529 Scimitar prototypes |
| S.14/48 | NA.21 | 09/07/48 | Naval Version of Sikorsky S.51 Helicopter | Westland Dragonfly HR.1 |
| 19/48P | NA.27 | | Production of a Naval Fighter to E.1/45 | Supermarine Attacker F.1 |
| | NA.31 | 195? | Skeeter for RN (A.13/49 Issue 2) | Saunders-Roe Skeeter |
| M.123 | NA.32 | 195? | Light carrier-borne Anti-submarine warfare aircraft to Spec. M.123 | Short Seamew |
| | NA.34 | May 1952 | Hooked Swift for Carrier Trials | |
| | NA.36 | | | de Havilland Sea Vampire T.22 |
| M.148 | NA.39 | 08/02/53 | Carrier borne strike aircraft to Spec. M.148T | Armstrong Whitworth AW.168, Blackburn Buccaneer, Short PD.13 |
| | NA.43 | | Anti-Submarine and General Purpose helicopter | |
| | NA.47 | 195? | Mixed rocket-jet interception fighter for Royal Navy | Saunders-Roe SR.177; cancelled 1957 |
| | NSR.6451 | 19?? | V/STOL carrier borne fighter aircraft – Naval Hawker Siddeley Harrier | BAE Sea Harrier |

## General Staff Requirements For Aircraft

| Spec | GSR | Year | Type | Related aircraft |
| | GSR.3335 | 196? | Helicopter – Westland Scout replacement | Westland Lynx |
| | GSR.3336 | 196? | Helicopter – Bell 47G Sioux replacement | Westland Gazelle |