List of Royal Air Force Conversion Units

Royal Air Force Conversion Units
Ensign of the Royal Air Force

Conversion Units and Operational Conversion Units (OCU) were training units of the Royal Air Force.

History

With the introduction of the new heavy bombers, the 4-engined Short Stirling, Avro Lancaster and Handley Page Halifax, into service, the Royal Air Force introduced Heavy Conversion Units. The Heavy Conversion Units began forming in late 1941 to qualify crews trained on medium bombers to operate the heavy bombers prior to assignment to an Operational Training Unit to gain experience before final posting to the operational squadrons.

After the end of the war their role was taken over by the Operational Conversion Units. Although the units had nominal bases it was usual for different flights and individual aircraft to be detached nearer the operational bases. Some of the Heavy Conversion Units were involved in bombing operations over Germany.

Royal Air Force Operational Conversion Units (OCU) are training units that prepare aircrew for operations on a particular type or types of aircraft or roles. Some OCUs have a Shadow or reserve squadron designation which is used if the unit has a war role.

List of Conversion Units

Unit	Dates	Aircraft	Base	Notes
226 OCU	Aug 46–Aug 49 Sep 49–Jun 55 Jun 63–Sep 74 Oct 74–Sep 91	Oxford I, Beaufighter X Hornet F.1 Mosquito III / TT.35 Tiger Moth II Vampire F.1 / FB.5 / T.11 Meteor F.3 / F.4 / T.7 / F.8 / FR.9 Tempest II Martinet I Spitfire XIV / XVI / XVIII / XIX / F.22 Javelin T.3 Lightning F.1 / F.1A / F.3 / T.4 / T.5 Jaguar GR.1 / T.2	RAF Molesworth RAF Bentwaters RAF Driffield RAF Stradishall RAF Middleton St. George RAF Coltishall RAF Lossiemouth	Formed at Molesworth by re-designating 1335 (Meteor) CU. Disbanded at Driffield to become 203 AFS. Re-formed at Stradishall by renaming 203 AFS.Re-formed at Middleton St. George by merging the Lightning Conversion Squadron and the Fighter Command Instrument Rating Squadron. Disbanded at Coltishall. Immediately re-formed at Lossiemouth by re-designating the Jaguar Operational Conversion Unit. Disbanded at Lossiemouth to become 16 (Reserve) Sqn
227 OCU 227 (AOP) CU	May 47–Dec 47 December 47–May 50	Tiger Moth II Oxford I Auster V Auster VI Auster T.7 Auster A.2/45 Harvard IIB	RAF Andover RAF Middle Wallop	Formed by re-designation of 43 OTU Became the Air Observation Post School.
228 OCU	May 47–Sep 61 May 65–Dec 66 August 68–Jul 92	Martinet I Master II Oxford I Tiger Moth II Brigand B.1 / T.4 / T.5 Tempest V Buckmaster T.1 Wellington XVIII Mosquito III / VI / NF.30 / TT.35 / NF.36 Balliol T.2 Valetta C.1 / T.3 / T.4 Prentice T.1 Vampire T.11 Meteor F.4 / T.7 / NF.11 / NF.12 / NF.14 Anson XIX Chipmunk T.10 Javelin T.3 / FAW.5 / FAW.7 / FAW.9 Canberra T.4 / T.11 Phantom FGR.2 Jet Provost T.4	RAF Leeming RAF Leuchars RAF Coningsby	Formed by merging 13 OTU and 54 OTU Became 64 (R) Sqn
229 OCU	Dec 50–Sep 74 November 84–Jul 92	Vampire FB.5 / T.11 Meteor T.7 / F.8 / TT.8 Hunter F.1 / F.4 / F.6 / T.7 / FGA.9 / FR.10 Tempest V Beaufighter X Oxford I / II Mosquito III / TT.35 Martinet I Anson T.21 / T.22 Sabre F.2 / F.4 Chipmunk T.10 Jet Provost T.3A Tornado F.2(T) / F.3	RAF Leuchars RAF Chivenor RAF Brawdy RAF Coningsby	Formed from 'B' and 'D' Flights of 226 OCU. Reformed 1957 at Chivenor, still there late 1962 Relocated to RAF Brawdy mid 1960s Disbanded 2 September 1974 at Brawdy to become the Tactical Weapons Unit Designated 65 (Shadow) Squadron from 31 December 86 Became 56 (R) Sqn.
230 OCU	Mar 47–Oct 52 August 53–Feb 55 May 56–Aug 81	Lancaster I / III Lincoln B.2 Mosquito III / B.35 / NF.36 Tiger Moth Anson XIX Vulcan B.1 / B.2 Hastings T.5 Canberra T.4	RAF Lindholme RAF Scampton RAF Upwood RAF Waddington RAF Finningley RAF Scampton	Formed by re-designting 1653 HCU Disbanded 15 oct 52 to become the Reserve Training Squadron became the Lincoln Conversion Flight at Upwood 1 February 1955.
231 OCU	Mar 47–Dec 49 December 51–Dec 90 May 1991–Apr 93	Lancaster I / III Anson XII / XIX / T.22 Mosquito III / VI / XVI / PR.34 / PR.34A / B.35 Chipmunk T.10 Meteor T.7 / PR.10 Canberra B.2 / PR.3 / T.4	RAF Coningsby RAF Waddington RAF Bassingbourn RAF Cottesmore RAF Marham RAF Wyton	Formed by re-designating 16 OTU re-formed at Bassingbourn by re-designation of 237 OCU Dis-banded at Wyton, 15 December 1990, to become the Canberra Standardisation and Training Flight Re-formed at Wyton 13 May 1990 from the Canberra Standardisation and Training Flight
232 OCU	Feb 55–Jun 65 February 70–Apr 86	Valiant B.1 Victor B.1 / B(PR).1 / B.1A / B.2 / BK.2 Canberra T.4	RAF Gaydon RAF Marham	At Gaydon, 30 June 1965, the Victor element became the Tanker Training Flight Re-formed at Marham 6 February 1970 by amalgamating the Victor (B.2) Training Flight and the Victor Training Unit
233 OCU	Sep 52–Sep 57 October 70–Sep 92	Vampire FB.5 / FB.9 / T.11 Balliol T.2 Meteor T.7 / F.8 Oxford I Tiger Moth II Mosquito III / PR.34A / TT.35 Tempest V Chipmunk T.10 Hunter F.1 Harrier GR.1 / GR.1A / GR.3 / GR.3A / T.2 / T.4 / T.4A / GR.5	RAF Pembrey RAF Wittering	Became 20 (R) Sqn
235 OCU	Jul 47–Oct 53	Sunderland V Short Seaford	RAF Calshot	Became the Flying Boat Training Squadron
236 OCU	Jul 47–Sep 56 July 70–Sep 92	Lancaster III Oxford I / II Beaufighter X Shackleton GR.1 / MR.1A Neptune MR.1 Martinet I Tiger Moth II Spitfire XVI Vampire FB.5 Anson XI / XIX Mosquito TT.35 Brigand T.5 Buckmaster T.1	RAF Kinloss RAF St Mawgan	Formed by re-designating 6 OTU
237 OCU	Jul 47–Dec 51 October 56–Jan 58 March 71–Oct 91	Oxford I Mosquito III / PR.34 / PR.34A Spitfire XVI / XIX Harvard IIB Meteor T.7 / PR.10 Canberra PR.3 / T.4 Hunter F.6 / T.7 / T.7A / T.7B / T.8C Buccaneer S.2A / S.2B	RAF Benson RAF Bassingbourn RAF Wyton RAF Honington RAF Lossiemouth	Formed by re-designating 8 OTU Became 231 OCU at Bassingbourn. Re-formed at Wyton, 56, by re-designating 'C' Squadron of 231 OCU. Re-absorbed by 231 OCU 2001 January 58.
238 OCU	1Jun 52–Mar 58	Buckmaster T.1 Brigand T.4 / T.5 Mosquito TT.35 Balliol T.2 Meteor NF.12 / NF.14 Valetta C.1 / T.3	RAF Colerne RAF North Luffenham	Formed by re-designating the Airborne Interception School
240 OCU	Jan 48–Apr 51 December 71–Oct 93	Anson I / X / XII / XIX Dakota IV Hastings MET.1 Valetta C.1 Wessex HC.2 Puma HC.1 ChinookHC.1	RAF North Luffenham RAF Odiham	Formed by merging 1333 (TS)CU with 1382 (T)CU
241 OCU	Jan 48–Apr 51 July 70–Oct 93	York C.1 Halifax IX Hastings C.1 Valetta C.1 Tiger Moth II Anson XI / XII Brittania C.1 / C.2 Andover C.1 Belfast C.1 VC10 C.1 Tristar C.1 BAe 146	RAF Dishforth RAF Brize Norton	Formed by re-designating 1332 HTCU. Became No. 55 (Reserve) Squadron RAF
242 OCU	Apr 51–Jul 92	Valetta C.1 Hastings C.1 / MET.1 / C.1A Beverley C.1 Argosy C.1 Andover C.1 Hercules C.1 / C.1K / C.1P / C.3 Tiger Moth II Anson XII Chipmunk T.10	RAF Dishforth RAF Lyneham	Became 57 (R) Sqn
1330 CU	Jun 44–Mar 46	Harvard IIA Baltimore IV / V Vengeance IV Hudson IIIA Expeditor I Marauder II / III Ventura V Hellcat II Beaufighter X Spitfire Vb Mustang IVA Anson I Dakota I / III Douglas DC-2 Mosquito III / IV Oxford I	RAF Bilbeis	1 (Middle East) Check and Conversion Unit re-designated.
1331 CU 1331 HTCU	Sep 44–Jan 46 December 46–Jan 48	Harvard IIB Vengeance IA / II / IV Beaufighter VI / X Spitfire VIII Mustang IV Mosquito III Oxford I Blenheim V Thunderbolt I / II Hurricane IIC Wellington XVI Liberator III / VI	RAF Mauripur RAF Risalpur RAF Syerston	Formed by re-designating Check and Conversion Flight.
1332 (T)HCU 1332 HTCU	Sep 44–May 47 May 47–Jan 48	Liberator III / V /VI / VII / IX York C.1 Stirling III Halifax VII / IX Skymaster C.1 Oxford I	RAF Longtown RAF Dishforth	Became 241 OCU.
1333 (TS)CU 1333 TSCU	Mar 45–Jul 46 July 46–Jan 48	Dakota III / IV Horsa I / II Halifax VII / IX Oxford II Miles Magister Tiger Moth Proctor IV Auster III	RAF Leicester East RAF North Luffenham	Formed by re-designating 107 OTU Merged with 1382 (T)CU to become 240 OCU.
1334 (TS)CU	Apr 45–Mar 45	Dakota III / IV	RAF Gujrat RAF Baroda
1335 (M)CU	Mar 45–Aug 46	Meteor F.1 / F.3 Oxford II Martinet I	RAF Colerne RAF Molesworth	Became 226 OCU
1336 (TS)CU 1336 TCU	Jun 45–Mar 46	Dakota III	RAF Welford
1380 (TS)CU 1380 TCU	Aug 45–Jan 46	Wellington X Anson I Proctor II	RAF Tilstock	Formed by re-designating 81 OTU
1381 (T)CU	Aug 45–Feb 48	Dakota III / IV Wellington X Miles Magister Tiger Moth II Oxford I	RAF Bramcote RAF Dishforth	Formed by re-designating 105 OTU
1382 (T)CU	Aug 45–Jan 48	Oxford I Miles Magister Dakota III / IV	RAF Wymeswold RAF North Luffenham	Formed by re-designating 108 OTU Merged with 1330 TSCU to form 240 OCU.
1383 (T)CU	Aug 45–Aug 46	Dakota III Oxford II Halifax VII	RAF Crosby-on-Eden	Formed by re-designating 109 OTU
1384 (HT)CU	Nov 45–Jun 46	Dakota I Oxford I York C.1	RAF Ossington RAF Wethersfield	Formed by re-designating No. 6 Lancaster Finishing School RAF
1385 (HTS)CU	Apr 46–Jun 46	Stirling V Halifax VII Horsa II Oxford I	RAF Wethersfield	Absorbed by 1333 TSCU
1584 (HB)CU	Nov 43–Feb 44	Liberator III	RAF Kolar RAF Salbani	Formed by re-designating No 1584 (Heavy Bomber Conversion) Flight RAF. Became 1673 HCU.
1651 CU 1651 HCU	Jan 42–May 44 May 44–Mar 45 March 45–Jul 45	Stirling I / III Lancaster I / III Oxford I Spitfire Vb Tiger Moth II Beaufighter X Halifax II	RAF Waterbeach RAF Wratting Common RAF Woolfox Lodge	During 42 it flew 49 operational sorties for RAF Bomber Command with a loss of five aircraft. Formed by merging No. 26 Conversion Flight RAF and No. 106 Conversion Flight RAF. Absorbed 15 Squadron Conversion Flight and 24 Squadron Conversion Flight.
1652 CU 1652 HCU	Jan 42–Jun 45	Halifax I / II / III / V Spitfire Vb Hurricane IIC Spitfire Vb Hurricane IIC / IV	RAF Marston Moor RAF Bentwaters	During 42 it flew 42 operational sorties for RAF Bomber Command with a loss of three aircraft. Formed by merging No. 28 Conversion Flight RAF and No. 109 Conversion Flight RAF. Absorbed 35 Squadron Conversion Flight
1653 CU 1653 HCU	Jan 42–Oct 42 November 43–Nov 46	Liberator II Stirling I / III Lancaster I / III Blenheim IV Ventura I Mosquito XIX Hurricane IIC Spitfire Vb Beaufighter VI	RAF Polebrook RAF Burn RAF Chedburgh RAF Lindholme RAF North Luffenham	Formed by re-designating No. 108 Conversion Flight RAF Became No. 230 Operational Conversion Unit RAF in March 47.
1654 CU 1654 HCU	May 42–Jul 42 July 42–Sep 45	Manchester I Lancaster I Halifax II / V Stirling III Oxford I Hurricane IIC Spitfire Vb	RAF Swinderby RAF Wigsley	During 42 it flew 12 operational sorties with a loss of two aircraft.
1655 MCU	Aug 42–May 43	Mosquito III / IV / XVI / B.20 / B.25 Blenheim IV Oxford I	RAF Horsham St. Faith RAF Upper Heyford RAF Marham	Became Mosquito Training Unit RAF at RAF Marham
1656 HCU	Oct 42–Nov 45	Lancaster I / III Halifax II / V Manchester I Spitfire IIa / Vb Hurricane IIC	RAF Lindholme Tiger Moth II	Formed by merging 103 and 460 Squadron Conversion Fights.
1657 HCU	Oct 42–Dec 44	Stirling I / III / IV Lancaster I / II Tomahawk IIB Oxford II Hurricane IIC	RAF Stradishall	Formed by merging 7, 101 and 149 Squadron Conversion Fights.
1658 HCU	Oct 42–Apr 45	Halifax I / II / III Oxford II Hurricane IIC	RAF Riccall	Formed by merging 10, 76 and 78 Squadron Conversion Fights.
1659 HCU	Oct 42–Mar 43 March 43–Sep 45	Halifax I / II / III Lancaster I / III Oxford II Spitfire IIa / Vb Hurricane IIC Tiger Moth	RAF Leeming RAF Topcliffe	Formed by merging 405 and 408 Squadron Conversion Fights. Trained Canadian aircrew.
1660 HCU	Oct 42–Nov 46	Lancaster I / II / III Halifax II Manchester I Mosquito XIX Stirling I / III Oxford I Spitfire Vc Hurricane IIC Lysander I de Havilland Puss Moth	RAF Swinderby	Formed by merging 61, 97, 106 and 7 Squadron Conversion Fights. Absorbed by No 1653 Heavy Conversion Unit RAF
1661 HCU	Nov 42–Aug 45	Lancaster I / II Halifax II / V Manchester I Mosquito XIII Stirling III Oxford II Spitfire Vb Hurricane IIC	RAF Waddington	Formed by merging 9, 44 and 49 Squadron Conversion Fights. Short Stirlings replaced the planned re-equipment with Handley Page Halifaxs.
1662 HCU	Jan 43–Apr 45	Lancaster I / II Halifax I / II / III / V Oxford II Spitfire Vb Hurricane IIC Tiger Moth II	RAF Blyton
1663 HCU	Mar 43–May 45	Halifax I / II / III / V Stirling I Oxford II Spitfire Vb Hurricane IIC	RAF Rufforth
1664 HCU 1664 (RCAF)HCU	May 43–Apr 44 April 44–Apr 45	Lancaster I / III Halifax II / III / V Oxford II Spitfire Vb Hurricane IIC	RAF Croft RAF Dishforth	The unit had the Canadian name Caribou.
1665 HCU 1665 (HT)CU	Apr 43–Jun 43 June 43–Jan 44 January 44–Aug 45 August 45–Jul 46	Halifax III / V / VI / VII Stirling I / III / IV Oxford II Spitfire IIa / Vb Hurricane X Tiger Moth II Mosquito VI Lancaster I	RAF Mepal RAF Woolfox Lodge RAF Tilstock RAF Saltby RAF Marston Moor RAF Linton-on-Ouse	Re-designated as 1665 (HT)CU on 10 August 1945
1666 HCU 1666 (RCAF)HCU	Jun 43–Oct 43 October 43–Aug 45	Halifax II / III / V Lancaster I / II / III Oxford II Spitfire IIa / Vb Hurricane IIC	RAF Dalton RAF Wombleton	The unit had the Canadian name Mohawk.
1667 HCU	Jun 43–Oct 43 October 43–Feb 44 February 44–Nov 45	Halifax II / V Oxford II Spitfire Vb Hurricane IIC Tiger Moth II Lancaster I / III	RAF Lindholme RAF Faldingworth RAF Sandtoft
1668 HCU	Aug 43–Nov 43 July 44–Mar 46	Lancaster I / II / III / X Mosquito XIX Spitfire Vb Hurricane IIC Beaufighter VI	RAF Balderton RAF Bottesford	Dis-banded November 43, re-formed July 44.
1669 HCU	Aug 44–Mar 45	Handley Page Halifax Lancaster I / III Spitfire Vb Hurricane IIC	RAF Langar
1670 (T)CU	Jun 44–Jan 45	Thunderbolt Harvard IIB	RAF Yelahanka	Became 8 Refresher Flying Unit
1670 CU	Feb 44–Jun 44	Beaufighter VI	RAF Baigachi	Formed from AI MkVIII Conversion Flight
1670 (M)CU	Feb 44–Aug 45	Blenheim V Mosquito III Oxford I	RAF Yelahanka
1673 HCU	Feb 44–Apr 44 April 44–Nov 44	Liberator III Tiger Moth II Anson I	RAF Salbani RAF Kolar	Formed by re-designating No 1584 (Heavy Bomber) Conversion Unit RAF.
1674 HCU	Oct 43–Nov 45	Liberator III / V / VI / VIII Halifax II Fortress I / II / IIA Wellington XIII Oxford I / II Hurricane IIC Martinet I	RAF Aldergrove various bases in Northern Ireland RAF Lossiemouth
1675 HCU	Oct 43–Aug 44 August 44–Oct 45	Liberator II Harvard IIA Hurricane IIB Argus II	RAF Lydda RAF Abu Sueir	Formed by re-designating 5 Heavy Bomber Conversion Unit, Lydda
1678 HCU	Sep 43–Jun 44	Lancaster II	RAF Foulsham RAF Waterbeach
1699 (BS)CU 1699 HCU	Oct 44–Jun 45	Fortress II / III Liberator VI Lancastrian II	RAF Oulton RAF Full Sutton	Became the Lancastrian Flight of No. 231 Squadron RAF
All-Weather OCU	?–?	Anson T.21 Vampire T.11 Meteor T.7 / F.8 / NF.12 / NF.14	nomadic
Argosy CU	Nov 61–Apr 63	Argosy C.1	RAF Benson	Became the Argosy Flight of OCU
Belvedere CU	Aug 64–Aug 68	Belvedere HC.1	RAF Odiham	Absorbed by the Short-Range Conversion Unit
Short-Range CU	Aug 64–Jul 67	Twin Pioneer CC.2 Wessex HC.2 Auster AOP.9	RAF Odiham	Became the Helicopter Operational Conversion Flight
Jaguar OCU	Jun 74–Sep 74	Jaguar GR.1 / T.2	RAF Lossiemouth	Formed from Jaguar Conversion Team. Became 226 OCU
5 Heavy Bomber Conversion Unit, Lydda	?–?	Liberator	RAF Lydda	Became 1675 HCU
Heavy Bomber Conversion Unit, Salbani	Sep 42–Jul 43	Liberator III	RAF Salbani	Became 1584 HCU
Heavy Glider Conversion Unit	Jul 42–Oct 44	Whitley V Albemarle I / GT.I / ST.II / ST.V Horsa I / II Oxford I / II Tiger Moth II Miles Magister	RAF Shrewton RAF Brize Norton	Became No 21 Heavy Glider Conversion Unit
21 HGCU	Oct 44–Dec 47	Whitley V Albemarle GT.VI Horsa I / II Oxford I Tiger Moth I Miles Magister Hotspur II / III Hadrian I Stirling IV Halifax III / VII Master II	RAF Brize Norton RAF North Luffenham	Formed by re-designation of the Heavy Glider Conversion Unit
22 HGCU	Oct 44–Dec 47	Albemarle GT.I / ST.II / ST.V / GT.VI Horsa I / II Oxford I Hadrian I	RAF Keevil RAF Blakehill Farm	Formed by re-designation of an element of the Heavy Glider Conversion Unit
23 HGCU	Oct 44–Dec 45	Albemarle GT.I / ST.V / ST.VI Horsa I / II Oxford I Hadrian I Proctor III	RAF Peplow	Formed by elements of 83 OTU the Heavy Glider Conversion Unit

See also

• List of Royal Air Force aircraft squadrons
• List of RAF Regiment squadrons
• List of Fleet Air Arm aircraft squadrons
• List of Army Air Corps aircraft squadrons
• List of Air Training Corps squadrons
• Battle of Britain RAF squadrons
• University Air Squadron
• Air Experience Flight
• Volunteer Gliding Squadron
• List of Royal Air Force & Defence Units & Establishments
• List of Royal Air Force & Defence Schools
• List of Royal Air Force aircraft independent flights
• List of RAF Squadron Codes
• List of Royal Air Force Conversion Units
• United Kingdom military aircraft serials
• United Kingdom aircraft test serials
• British military aircraft designation systems
• Royal Air Force roundels

References

• Jefford, Wing Commander C.G., MBE,BA,RAF (Retd). RAF Squadrons, a Comprehensive Record of the Movement and Equipment of all RAF Squadrons and their Antecedents since 12. Shrewsbury: Airlife Publishing, 98 (second edition 01). ISBN 1-84037-141-2.
• Sturtivant, Ray ISO and John Hamlin. RAF Flying Training And Support Units since 12. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd, 07. ISBN 0-85130-365-X.
• Ray Sturtivant, Flying Training And Support Units since 12, 07, Air-Britain, UK, ISBN 0-85130-365-X
• Lake, Alan. "Flying Units of the RAF".Airlife Publishing. Shrewsbury. 1999. ISBN 1-84037-086-6