British military aircraft designation systems
British military aircraft designations are used to refer to aircraft types and variants operated by the armed forces of the United Kingdom.
Since the end of the First World War, aircraft types in British military service have generally been known by a service name, with individual variants recognised by mark numbers often in combination with a letter to indicate the role.in contrast to the systems such as that used in the United States, where an aircraft type is primarily identified by an alphanumeric designation.
The British military aircraft designations should not be confused with the serial number used to identify individual aircraft, nor with U.S. aircraft designations or manufacturer's designations, though Mark numbers were used to indicate aircraft built for other nations e.g. Hawker Hunter Mk 58 was a Hunter F.6 for the Swiss Air Force.
No designation system was introduced during World War I that covered more than the products of a single manufacturer. The Admiralty frequently referred to designs by the serial of the first aircraft of that type to be accepted for service.
The military designation system
In this system, which has been used since the end of World War I, each aircraft designation consists of a name, a role prefix and a mark number.A unified official naming system was introduced in February 1918 by the Ministry of Munitions, the scheme would use classes of names related to the role. Fighter aircraft were to be animals, plants or minerals, bomber aircraft were to have geographical names and "heavy armoured machines" would be personal names from Mythology. The classes were further divided by size of aircraft and land or sea-based, for example a three-seater sea-based fighter would be named after shellfish. Italian towns were to be used for single-seat land-based bombers.
Following the formation of the Royal Air Force in April 1918 the Ministry of Munitions introduced a new system as Technical Department Instruction 538. They mainly followed the February 1918 scheme but certain names already used for engines were excluded, for example birds of prey were used by Rolls-Royce. The names related to zoology, geography and mythology were withdrawn in 1927 and the Air Ministry introduced names with the initial letters relating to role, for example "C" for troop carriers as used by the Handley Page Clive. A further change was made in 1932 and 1939 to use more appropriate names. Fighters were to use General words indicating speed, activity or aggressiveness and trainer would be words indicationg tuition and places of education.
Bombers were to be named after inland towns in the British Empire, for example the Avro Lancaster and Fairey Battle. With the introduction of Helicopters these were to be named after trees but only the Bristol Sycamore was named in this scheme.
Names
The name of an aircraft type would be agreed between the Air Ministry or Admiralty and the manufacturer/importer when the order was placed. Names generally followed one or a number of patterns:- Alliteration was particularly common; e.g. aircraft from Vickers-Armstrongs were given names starting with V, Hawker Aircraft, names starting with H, etc. This began during the First World War, when aircraft manufacturers were given an initial pairing of letters to use in the naming of their aircraft: e.g. Boulton Paul Ltd were given "Bo". From this and the requirement to use the names of birds or insect for fighter aircraft, their first in-house fighter design was the Boulton Paul Bobolink. For bombers the additional requirement was a placename, hence the Boulton Paul Bourges; and its contemporaries – the Airco Amiens and Vickers Vimy.
- Heavy bombers received the names of cities and towns – Short Stirling, Avro Lancaster, Handley Page Halifax. Likewise Transport aircraft also received the names of cities and towns – Avro York, Vickers Valetta, Handley Page Hastings, Blackburn Beverley.
- Flying boats were given the names of coastal or port communities – Saro London, Supermarine Stranraer, Short Sunderland.
- Land-based maritime patrol aircraft were named for naval explorers – Avro Anson, Lockheed Hudson, Avro Shackleton, Bristol Beaufort.
- Aircraft for army co-operation and liaison and gliders were given names associated with mythological or legendary leaders; e.g. Westland Lysander, Airspeed Horsa, General Aircraft Hamilcar, Slingsby Hengist. A sense of irony was present when some of the names were chosen as Hengist and Horsa were the mythical Germanic leaders in the invasions of the British Isles in the 5th century.
- American aircraft, whether purchased directly or sourced under Lend-Lease, were given American-themed names following established patterns, e.g. the Martin Baltimore, Consolidated Catalina. The American services, with the exception of the U.S. Navy, were not generally in the habit of giving aircraft names, and many British-chosen names would later be adopted; e.g. the North American P-51 Mustang began life as the North American Mustang Mk.I with the RAF. U.S. Navy names, conversely, were being increasingly adopted by the Fleet Air Arm as 1942 and 1943 progressed, as in the case of the Grumman F4F Wildcat shedding its alternative Fleet Air Arm "Martlet" name in favour of "Wildcat", the original American naval name.
- Naval versions of aircraft not originally ordered for the Fleet Air Arm were given the prefix "Sea" such as with the Hawker Sea Hurricane and de Havilland Sea Venom while Seafire for the navalised Supermarine Spitfire was a contraction of "Sea Spitfire". Sometimes the naval version entered service without a corresponding land-based type doing so, as with the Hawker Sea Fury and de Havilland Sea Vixen.
- Naval aircraft ordered as such had names with a nautical theme – e.g. Supermarine Walrus, Blackburn Roc, Fairey Gannet. Torpedo bombers were given 'fish' names, e.g., Blackburn Shark, Fairey Swordfish, Fairey Barracuda. Mythological names, particularly with an association with water were common, such as Blackburn Iris – named for the goddess of sea and sky, and Nimrod the mighty hunter, used for the Hawker Siddeley Nimrod and Hawker Nimrod. Nimrod aside, many naval fighters were named for birds – such as the Fairey Flycatcher, Fairey Fulmar, Blackburn Skua and, before the aforementioned adoption of the U.S. Navy's existing names for Fleet Air Arm aircraft of American origin, Grumman Martlet for the F4F fighter.
- Training aircraft were given names related to academic institutions – Airspeed Oxford, North American Harvard, Boulton Paul Balliol, Fairchild Cornell. As with other American aircraft purchased, appropriate US names were used – the Harvard and Cornell universities. Alternative names for teachers were also used – De Havilland Dominie, Percival Provost, Miles Magister, Percival Proctor.
- Aircraft built for one role such as the Avro Anson or Armstrong Whitworth Albemarle but converted to other roles rarely changed their names. However significant changes in a design might result in a name change – the Avro Manchester was renamed Avro Lancaster, which was in turn renamed Avro Lincoln as the design was improved, however the Lincoln had more in common with the Manchester than the late models of Spitfire did with the early versions so it wasn't consistent.
- A trend might also be followed by a manufacturer – Hawker Hurricane, Typhoon, Tornado, Tempest.
- Where civilian aircraft types have been taken into service, their existing names or alphanumeric designations have often been retained, e.g. the Vickers VC10 or Lockheed TriStar.
Role prefixes
Role prefixes used at various times comprise:| Prefix | Description | Example |
| A | Airborne | Halifax A.VII |
| AEW | Airborne early warning | Sentry AEW.1 |
| AH | Army helicopter | Lynx AH.7 |
| AL | Army liaison | Islander AL.1 |
| AOP | Airborne observation post | Auster AOP.9 |
| AS | Anti-submarine | Gannet AS.1 |
| ASR | Air-sea rescue | Sea Otter ASR.II |
| ASaC | Airborne Surveillance and Control | Sea King ASaC.7 |
| B | Bomber | Vulcan B.2 |
| B | Bomber interdictor | Canberra B.8 |
| B | Bomber/tanker | Valiant B.1 |
| B | Bomber/Photo Reconnaissance | Valiant B.1 |
| C | Transport | Hercules C.4 |
| CC | Communications transport | BAe 125 CC.3 |
| COD | Courier – later Carrier – On-board Delivery | Gannet COD.4 |
| D | Drone | Shelduck D.1 |
| DW | Mine Exploding | Wellington DW.1 |
| E | Electronics | Canberra E.15 |
| ECM | Electronic Counter-Measures | Avenger ECM.6 |
| F | Fighter | Typhoon F.2 |
| FA | Fighter/Attack | Sea Harrier FA.2 |
| FAW | Fighter, All-Weather | Javelin FAW.9 |
| FB | Fighter-Bomber | Sea Fury FB.11 |
| FG | Fighter/Ground attack | Phantom FG.1 |
| FGA | Fighter/Ground Attack | Hunter FGA.9 – |
| FGR | Fighter/Ground attack/Reconnaissance | Phantom FGR.2 |
| FR | Fighter/Reconnaissance | Hunter FR.10 |
| FRS | Fighter/Reconnaissance/Strike | Sea Harrier FRS.1 |
| GA | Ground Attack | Hunter GA.11 |
| GR | General Reconnaissance | Lancaster GR.III |
| GR | Ground attack/Reconnaissance | Harrier GR.9 |
| HAR | Helicopter, Air Rescue | Sea King HAR.3 |
| HAS | Helicopter, Anti-Submarine | Sea King HAS.2 |
| HC | Helicopter, Cargo | Chinook HC.2 |
| HCC | Helicopter, Communications | Squirrel HCC.1 |
| HF | High-altitude fighter | Spitfire HF.VII |
| HM | Helicopter, maritime | Merlin HM.1 |
| HMA | Helicopter, maritime attack | Lynx HMA.8 |
| HR | Helicopter, Rescue | Dragonfly HR.5 |
| HT | Helicopter, Training | Griffin HT.1 |
| HU | Helicopter, Utility | Sea King HU.4 |
| K | Tanker | VC10 K.4 |
| KC | Tanker / Cargo | TriStar KC.1 |
| L | Low-altitude fighter | Seafire L.III |
| LF | Low-altitude fighter | Spitfire LF.XVI |
| Met | Meteorological reconnaissance | Hastings Met.1 |
| MR | Maritime Reconnaissance | Nimrod MR.2 |
| MRA | Maritime Reconnaissance and Attack | Nimrod MRA.4 |
| NF | Night Fighter | Venom NF.2 |
| PR | Photographic Reconnaissance | Canberra PR.9 |
| R | Reconnaissance | Sentinel R.1 |
| RG | Reconnaissance/Ground attack | Protector RG.1 expected in service 2024 |
| S | Strike | Buccaneer S.2 |
| SR | Strategic Reconnaissance | Victor SR.2 |
| T | Training | Hawk T.1 |
| TF | Torpedo Fighter | Beaufighter TF.X |
| TR | Torpedo / Reconnaissance | Sea Mosquito TR.33 |
| TT | Target tug | Canberra TT.18 |
| TX | Training glider | Cadet TX.3 |
| U | Drone – | Meteor U.15 |
| W | Weather research | Hercules W.2 |
Mark numbers
Starting in the interwar period, variants of each operational type were usually indicated by a mark number, a Roman numeral added to the type name, usually preceded by "Mark", "Mk." or "Mk". Mark numbers were allocated sequentially to each new variant, the new mark number signifying a 'major' change such as a new engine-type. Sometimes an alphabetic suffix was added to the mark number to indicate a minor change. Occasionally, this letter indicated a change in role, e.g. the Blenheim Mk I bomber was adapted to the Blenheim Mk IF long-range fighter. Sometimes a minor but otherwise significant change in an aircraft would necessitate a new mark number, e.g., when the Lancaster I was fitted with Packard-built Merlin engines, which used a different make of carburettor from the Rolls-Royce-built ones, the Lancaster I became a Lancaster III. Otherwise, these two aircraft were identical in appearance and performance and normally indistinguishable from each other but needed to be identified differently for maintenance.During the Second World War, as aircraft ordered for one purpose became adapted to a multitude of roles, mark numbers became prefixed with letters to indicate the role of that variant. Aircraft of the same mark that were adapted for different purpose would then be differentiated by the prefix. For instance the Defiant Mk I was adapted to a night fighter, the Defiant NF Mk II, some of which were later converted to target tugs as the Defiant TT Mk II. Where there was a Sea- variant, this would have its own series of mark numbers.
Occasionally other 'minor' but nonetheless important changes might be denoted by series numbers, preceded by "Series", "Srs." or "Srs". The series number denoted a revision during the production run of a particular Mark. This again could then have an additional letter-suffix.
Export variants of British military aircraft are usually allocated mark numbers from a higher range of numbers, usually starting at Mark 50. A converse convention was adopted for the Canadian-designed de Havilland Canada DHC-1 Chipmunk, where the sole British service variant was designated Chipmunk T.10.
Up until the end of 1942, the RAF always used Roman numerals for mark numbers. 1943–1948 was a transition period during which new aircraft entering service were given Arabic numerals for mark numbers but older aircraft retained their Roman numerals. From 1948 onwards, Arabic numerals were used exclusively. Thus, the Spitfire PR Mk XIX became the PR Mk 19 after 1948. With this change, the Sea- variants were allocated their own range within one common series for all variants.
Format of designation
The system has been largely unchanged since 1948 with the addition of more prefixes as new roles have arisen.For example, the first Lockheed Hercules variant in RAF service was the Hercules C.1. A single example was adapted for weather monitoring purposes and became the Hercules W.2. The stretched variant became the Hercules C.3. With aircraft with a long service life, as their function changes over time, the designation letters and sometimes the mark digit will change to reflect this. The practice of restarting the mark numbers for the naval variant where the name was changed continued – e.g. the naval version of the Harrier, the Sea Harrier, marks started again at FRS Mk 1 – whilst variants where the name was unchanged for the naval version such as the Lynx have a single set of numbers for both land and naval variants. In the case of the Sea King, which began as a naval aircraft, the RAF kept the name and it also has a single set of numbers.
The post-1948 mark numbers are variously presented in full or abbreviated forms, and either with or without a full stop between the prefix and mark number. The use of the "Mark" or "Mk." has gradually been dropped.
Other designation systems used for UK military aircraft
Specification numbers
From 1920 to 1949, most aircraft had an associated Air Ministry specification number. Prototype aircraft would be produced under contract and would be referred to by Manufacturer Name and Specification Number. If accepted they would get a service name. For example, the "Fairey 6/22" was built to meet the 6th specification issued in the year 1922; it was accepted as the Fairey Flycatcher. Later, a preceding letter was added to the Specification Number to identify the type of aircraft; e.g. specification B.28/35 for a bomber was the 28th specification issued in 1935; in this case the specification was specifically written for the Bristol 142M, a modification of Bristol's Type 142 private venture civil aircraft for military use as a bomber, which would enter service as the Bristol Blenheim Mk 1 light bomber.Manufacturers designations
From about 1910, the largest single designer of aircraft for the British Army's Royal Flying Corps was the Royal Aircraft Factory. The Royal Aircraft Factory designated its types according to either the layout of the aircraft or its role – e.g. Royal Aircraft Factory S.E.5, the "S.E." prefix representing Scouting Experimental. In practice successful Royal Aircraft factory designs were largely built by other manufacturers though still known by the Factory designationsSome examples of manufacturers designations and the corresponding service designations are shown below: