Air of Authority - A History of RAF Organisation

Development of Squadron Markings and Codes 1939 - 1945

Squadron code letters were introduced in March/April 1939 as a means of identifying squadrons.  Three letters were used, two to denote the squadron and a third to denote the individual aircraft within the squadron.  On the outbreak of war the two letter allocations were changed to confuse enemy intelligence.

Given below are the relevant excerpts taken from Air Ministry Orders of the time and reproduced here by kind permission of the Controller of Her Majesty's Stationery Office.  Text in red are notes made by the author, italics indicated an opinion.

AMO A154/39 (27 April 1939)

Identification Markings on Aircraft and Marking of Unit Equipment in Operational Commands

1.    It has been decided to adopt a standard system of identification markings on aircraft throughout the services, at home and abroad, and on those items of unit equipment in operational commands which are liable to be taken into the air.

2.    The system is to be adopted forthwith. However, it would have taken some time for this system to be fully adopted and for some time aircraft in previous schemes would still have been in use.

3    No markings other than those described hereunder are to be permitted.

Aircraft identification markings

4    The identification markings to be carried on aircraft are as follows: -

AMO A520/39 dated 7 December 1939 amended Paragraph 4 as shown below: -

4.    The identification markings to be carried on aircraft are as follows: -

Note. - Fighter aircraft: -

(i)    are not to carry the national marking on the lower surface of the wing tip, (except fighters operating over France which are to carry the red, whit and blue roundels*):

(ii)   the lower surface of the starboard plane and half the under surface of the fuselage is to be painted white.  The corresponding portside is to be painted black.

5    The code letters allotted to squadrons are shown at the appendix to this order.  They are to be painted in grey paint (Stores Ref. 33B/157).  The letters are to be 48 in. high and are to be made up of strokes 6 in. in width.  Smaller letters are to be used only when the space available on the fuselage makes such a course unavoidable.

6    Squadron badges may be carried if desired on aircraft of operational commands but they must be removable at short notice without leaving any trace.

Marking of unit equipment

7    The equipment of one squadron will be distinguished from that of another at the same station by the system of colour marking described below.

8    Each squadron at a station is to be allotted a colour by the station commander.  A band is to be painted on articles of squadron equipment in the colour allotted to the particular squadron.  This colour system is to be standard at all stations, the colours to be used being white for the first squadron, green for the second, red for the third and yellow in the exceptional case of a fourth squadron at the same station.

9    Aircraft equipment - In no circumstances is any removable  article of aircraft equipment or any article which is carried in aircraft to be marked with the number of the squadron to which the item of equipment belongs.

10   Flight equipment - The addition of flight and/or aircraft lettering on articles of squadron equipment including those items taken into the air is permissible.  The colour used must conform to the colour allotted to the squadron by the station commander.

The orders quoted above have been amended to AMO A298/39 issued on 3 August 1939 and *AMO 520 dated 7 December 1939.

APPENDIX

AMO A926/40 (12 December 1940), amended by AMO A157/41 (6 March 1941)

Aircraft Colouring and Recognition Markings

1. The previous instructions regarding identification markings on aircraft, contained ix AMO 154/39, as amended by A298/39 and A520/39, are superseded by those contained in the following paragraphs and that order is accordingly cancelled.  A further order dealing with the marking of unit equipment will be issued shortly.

2. These regulations apply to all RAF aircraft at home and to aircraft flown, or shipped to overseas commands.  They, may be varied to meet operational requirements at the discretion, of air officers commanding overseas commands, with Air Ministry approval.

3. These regulations come into force forthwith.  It would have taken some time for these changes to be fully implemented and older aircraft would have continued to be seen in the previous scheme.

4. Markings other than those described in Part II below are not permitted and any aircraft carrying additional markings will be regarded with suspicion and may be treated as hostile

A30/41 of 9 January 1941 amended the above as follows: -

1. The following regulations apply to all service aircraft at home and overseas.  Departure from, and additions to, the standard colour schemes and markings are not to be made without prior Air Ministry approval.

2. The provisions of this order, which take immediate effect, supersede those contained in all previous Air Ministry Orders on this subject.

I.         Camouflage Colouring of British Aircraft, including American and Allied Types in use by British Air Forces

5. 5.      Explanation of terms

   1. Temperate land scheme camouflage. - This consists of two colours DARK GREEN and DARK EARTH.  Aircraft of the Middle East Command are coloured MIDSTONE in place of the DARK GREEN.

   2. Temperate sea scheme camouflage. - This consists of two colours DARK SLATE GREY and EXTRA DARK SEA GREY.

   3. Upper surface - This term comprises all surfaces visible in plan view from above, together with the following miscellaneous surfaces :-

      1. Top surfaces of the lower main planes of biplanes.

      2. Upper surfaces of floats of float-planes.

      3. Inter-plane struts on biplanes.

   4. Under-surfaces - This term comprises all surfaces visible in plan view from below, including the following :-

      1. Under-surfaces of the upper main planes of biplanes.

      2. Fixed undercarriage and float supporting struts.

      5. Wheel spats on fixed undercarriages and under-surfaces of floats.

5. Side surfaces - This term comprises all major surfaces visible in side view, including both sides of fins and rudders.  Except as otherwise provided in this order, tail unit side surfaces are to be coloured as upper surfaces.  All other side surfaces will be proportionately painted in the colour prescribed for upper and under-surfaces respectively, the dividing line being determined by the relative amount of side surface visible when viewed from directly above or directly below.  At this dividing line the two contrasting colours of upper and under surfaces are to be merged into one another so as not to form a definite line of demarcation.

Exception - On aircraft the under-surfaces of which are painted yellow (see para. 6 (ii) (b) and (g) below) the upper surface camouflage is to be extended downwards to cover the whole of the side surfaces of the fuselage and, in addition, the wheel spats and undercarriage fairings of such aircraft with fixed undercarriages are to be camouflaged as for upper surfaces.

6. 6.  Colour schemes of landplanes, except Fleet Air Arm aircraft -

   1. Upper surfaces - The upper surfaces of all landplanes, except Fleet Air Arm and night fighter aircraft, but including target (pilotless) aircraft, are to be camouflaged in the temperate land scheme, but bomber aircraft with matt black under-surfaces may also have fins and rudder painted black.  Night fighters are to be coloured matt black (special night) on all surfaces.  National markings are not to be altered or obscured.

   2. Under-Surfaces - The colouring of the under-surfaces is to be as follows :-

      1. Operational aircraft - The under-surfaces of all operational aircraft are to be either black or duck-egg blue, at the discretion of commands, to meet operational requirements.  The following classes of aircraft are to be produced with duck-egg blue (Sky Type “S") under-surfaces:-

         Day fighters	Blenheim bombers
         Army co-operation	Close support bombers
         General reconnaissance	Troop carriers
         Torpedo bombers	Bomber transports.

         Day fighters are to be coloured black on the under-surface of the port wing, by aircraft storage units before delivery to Fighter Command units.

         All bombers, except those referred to above, are to be produced with matt black (special night) under-surfaces.  The black colouring is to be extended to include the side surfaces of the fins and rudders.  Furthermore, so far as aircraft in this category are concerned, under-surfaces are to be interpreted as including the side surfaces up to the outline of the top quarter of the fuselage cross-section.  The national markings on these surfaces are to be left unchanged and not obscured by the matt black finish.

      2. Non-operational aircraft (excluding those mentioned in sub­paras. (c) to (f) below) are to be coloured yellow.  Service types of aircraft in operational training units, air fighting development units, the Fighter Interception Unit and No. 2 School of Army Co-operation are to conform to the normal colour scheme for the aircraft ro1e.

      3. Target towing aircraft - Black inclined stripes are to be painted on a yellow background, the black stripes being 3 ft. wide with 6 ft. yellow spacing.

      4. Anti-aircraft (searchlight) co-operation aircraft - Black.

      5. Target (pilotless) aircraft - Duck-egg blue.

      6. Ambulance aircraft - White.

      7. Prototype and experimental aircraft, including private venture aircraft - Yellow. Operational aircraft temporarily on the strength of experimental establishments for short periods may retain their normal colourings.

7. Colour schemes of flying boats, float planes, amphibians and Fleet Air Arm aircraft -

   1. Upper Surfaces - Upper surfaces of all flying boats, float planes, amphibians and Fleet Air Arm aircraft are to be camouflaged in the temperate sea scheme, with the exception of target (pilotless) aircraft whose upper surfaces will be in the temperate land scheme.

   2. Under-surfaces - The under-surfaces of all flying boats, float planes, amphibians and Fleet Air Arm aircraft are to be painted duck-egg blue (Sky Type “S”).

8. Photographic Reconnaissance Unit and No. 421 Flight - Aircraft of the Photographic Reconnaissance Unit and No. 421 Flight are coloured and marked in accordance with operational requirements and the colour schemes need not conform to the standard system.  Special arrangements are to be made by the Photographic Reconnaissance Unit and No. 421 Flight with Headquarters, Fighter Command, for the safety of these aircraft.

 II. MARKINGS OF BRITISH AIRCRAFT, INCLUDING AMERICAN AND ALLIED TYPES IF USED BY BRITISH AIR FORCES

9. -

   1. Upper surfaces - Red and blue roundels am to be carried on the upper surfaces of the wing-tips.

   2. Sides of fuselage - A red, white and blue roundel, surrounded by a yellow ring, is to be carried on each side of the fuselage.

   3. Fin markings - Vertical red, white and blue stripes (with red stripe leading).  These stripes are to be 8 in. wide and 27 in. high, forming a rectangle of 27 in. by 24 in. or an area conforming to this as nearly as the size and shape of fin permits.  The marking is to he placed on the fin against the hinge post immediately above the tail plane.

   4. Under-surfaces - Roundels are not to he carried on the under­surfaces of operational aircraft, except day fighters, which are to carry red, white and blue roundels.  The roundel on the black surfaces of the port wing of day fighters is to be surrounded by a yellow ring.

      Anti-aircraft (searchlight) co-operation aircraft are to carry red, white and blue roundels surrounded by a yellow ring.  Target (pilotless) aircraft may carry roundels on the under-surface at the discretion of the unit commanders for training purposes.

      Non-operational aircraft with yellow under-surfaces, and ambulance aircraft are to carry red, white and blue roundels on the under-surfaces of the wing tips.

   5. Registration number - The registration number allotted to the aircraft is to be carried by all aircraft at the rear end of the fuselage.  Note - Training aircraft in the Flying Training Command and Technical. Training Command also carry registration numbers on the under-surfaces of the wing.

   6. Code letters. Code letters are carried by Service types in operational units and operational training units.  The two Code letters and one letter to indicate individual aircraft are to be painted in grey paint and placed before and behind the roundels on the fuselage.  The code and individual letters may be placed two before and one behind the roundels or vice versa.  The letters are to be 48 in. high and are to be made up of strokes 6 in. in width.  Smaller letters are to be used only when the space available on the fuselage makes such a course unavoidable.

   7. Special markings - Special markings may not be carried except: -

      1. by aircraft of Allied Air Forces operating under Royal Air Force control, or when it is desired to distinguish particular or pre­sentation aircraft; in such cases a marking not larger than 9 in. by 6 in., or an inscription in 2 in. grey letters, may be carried on the sides of the fuselage, forward of the trailing edge of the wing, on the authority of the command headquarters concerned ;

      2. by non-operational types of aircraft with yellow under-surfaces, when large figures may be carried on the sides of the fuselage in order to meet training requirements ;

      3. by ambulance aircraft which carry the " Geneva " Red Cross on a white disc of the same diameter as the yellow ring of the standard roundel, immediately aft of the roundel on each side of the fuselage ;

      4. by day fighters which carry an 18 in. band of duck-egg blue (Sky Type " S ") right round the fuselage, immediately forward of the tail plane, and have the airscrew spinner painted duck-egg blue (Sky Type " S ").

(AMOs A154/39, A298/39 and A520/39 cancelled.)

A.31/41  Marking of Unit Equipment (9 January 194l.)

1. The equipment of one squadron will he distinguished from that of another at the same station by the system of colour marking described below.

2. Each squadron at a station is to allotted a colour by the station commander.  A band is to be painted on articles of squadron equipment in the colour allotted to the particular squadron.  This colour system is to be standard at all stations, the colours to be used being white for the squadron, green for the second, red for the third and yellow in the exceptional case of a fourth squadron on at the same station.

3. Aircraft equipment - In no circumstances is any removable article aircraft equipment or any article which is carried in aircraft to be marked with the number of the squadron to which the item of equipment belongs.

4. Flight equipment - The addition of flight and/or aircraft lettering (referred to in para 9 (vi) of AMO A926/40) on articles of squadron equipment, including those items taken into the air, is permissible.  The colour used must conform to the colour allotted to the squadron by the station commander.

A.513/41  Camouflage Colouring and Markings of Aircraft (10 July 194l.)

 1.  A.M.0. A.926/40, as amended by A.30/41 and A.157/41, is super­seded by the instructions contained in this order, which take effect immediately.

I.    Camouflage and Colouring of Aircraft

 2.  (i) A series of five patterns has been prepared defining the various camouflage and colouring schemes.  They are applicable to all aircraft irrespective of the peculiarities of each type.

(ii) Detailed blueprints conforming to the patterns are prepared by the manufacturers, showing the demarcation of the camouflage and colour­ing requirements for each type of aircraft.  Copies of approved blueprints are printed and held by the Ministry of Aircraft Production (R.T.P.4).  In the interests of economy no general distribution is made and blueprints are issued only on demand for workshop use.

3. R.A.F. landplanes - (i) Operational aircraft for service at home -

(a)   Temperate land scheme camouflage, consisting of two colours, dark green and dark earth, is to be used for the upper surfaces of all aircraft, except those mentioned in sub-para. (c) below.

Bomber aircraft with matt black under-surfaces are to have their fins and rudders painted matt black.

(b) The under-surfaces of all aircraft, except those mentioned in sub-para. (c,) below, are to be matt black, duck-egg blue (Sky Type " S") or a combination of these colours, at the discretion of commands.

(c)  Night fighters are to be coloured matt black (special night) on all surfaces.

Aircraft of photographic reconnaissance units are to be coloured and marked in accordance with operational requirements, and the colour scheme need not conform to the standard system. 

(ii)  Operational aircraft for service abroad - (a) The upper surfaces are to be camouflaged in accordance with the instructions contained in sub-para. (i) (a) above, or dark green and mid-stone, according to the nature of the country in which they are to operate.

(b)  The under-surfaces are to be camouflaged in accordance with the instructions contained in sub-para. (i) (b) above.

(iii)  Training and communication aircraft - (a) The upper surfaces are to be camouflaged in accordance with the instructions contained in sub­-para. (i) (a) above.

(b)  The under-surface, of aircraft, except fighter training aircraft, are to be coloured yellow.

The under-surfaces of fighter training aircraft are to be coloured in accordance with the instructions contained in sub-para. (i) (b) above.

(iv)  Target-towing aircraft - (a) The upper surfaces are to be camou­flaged in accordance, with instructions contained in sub-para. (i) (a) above

(b)   The under-surfaces are, to be painted yellow with black inclined stripes, the black stripes being 3 ft. in width and at intervals of 6 ft.

(v)   Anti-aircraft (searchlight) cooperation aircraft. - (a) The upper surfaces are to be camouflaged in accordance with the instructions contained in sub-para. (i) (a) above.

(b)   The under-surfaces are to be painted black.

(vi)   Target aircraft--(a) The upper surfaces are to be camouflaged in accordance with the instructions contained in sub-para. (i) (a) above.

(b)    The under-surfaces are to be painted duck-egg blue (Sky Type  “S”)

(vii)   Ambulance aircraft - (a) The upper surfaces are to be camouflaged in accordance with instructions contained in sub-para. (i) (a) above 

(b)    The under-surfaces are to be painted white.

(viii)  Prototype, and experimental aircraft. - (a) The upper surface, to be camouflaged in accordance with the instructions contained in sub­-para. (i) (a) above,.

(b)    The under-surfaces are to be, painted yellow.  Operational aircraft temporarily on the strength of experimental establishments may retain their normal colourings.

(ix)  Aircraft in miscellaneous units - Aircraft in operational training units, air fighting development units. fighter interception unit, special duty flights, fighter experimental establishment, No. 2 School of Army Co-operation and the Central Gunnery School, are to conform to the normal colour scheme for the aircraft ro1e.

4. R.A.F. flying-boats, float planes and amphibians - (i) Temperate sea scheme camouflage, consisting of' two colours, dark slate grey, and extra dark sea grey, is to be used for the upper surfaces of all aircraft except target aircraft, whose upper surfaces are to be camouflaged in accordance with the instructions contained in para. 3 (i) (a) above.

(ii)      The under-surfaces of all aircraft are to be painted duck-egg blue (Sky-Type “S”).

II.   Markings of British Aircraft

5. (i)  Upper surfaces - Red and blue roundels are to be carried on the upper surfaces of the wing tips.

(ii)  Side of fuselage - Red, white and blue roundel surrounded by yellow ring is to be carried on each side of the fuselage.

(iii)  Fin markings - Vertical red, white and blue stripes (with red stripe leading).

(iv) Under-surfaces - (a) Roundels are not to be carried on the under-surfaces of operational aircraft, except day fighters, which may carry red, white and blue roundels.  On black under-surfaces of day fighters the roundel is to be surrounded by a yellow ring.

(b) Anti-aircraft (searchlight) cooperation are to carry red, white and blue roundels surrounded by a yellow ring.

(c)  For training purposes, target aircraft may carry roundels on the' under-surface, at the discretion of unit commanders.

(d)  Training, Communication, prototype and experimental aircraft with yellow under-surface, and ambulance aircraft, are to carry red, white and blue roundels on the under-surfaces of the wing tips.

(v)  Registration numbers - (a) The registration number allotted to the aircraft is to be carried by all aircraft, at the rear end of the fuselage.

(b)  Aircraft coloured yellow for training purposes are to carry these numbers on the under-surfaces of the wing.

(vi)  Code letters are carried by service types in operational units, and operational training units.  The two code letters, and one letter to indicate individual aircraft, are to be painted in grey paint and placed before and behind the roundels on the fuselage.  The, code and individual letters may be placed two before and one behind the roundels or vice versa.  The letters are to be 48 in. high and are to be made up of strokes 6 in. wide.  Smaller letters are to be used only when the space available on the fuselage makes such a course unavoidable.  These letters are to be painted on by units after receipt from No. 41 Group.

(vii)  Special markings may not be carried except-

(a)  by aircraft of allied air forces operating under R.A.F. control or when it is desired to distinguish particular or presentation aircraft.  In such cases a marking not larger than 9 in. by 6 in. or an inscription in 2 in. grey letters, may be carried on the sides of the fuselage forward of the trailing edge of the wing, on the authority of the command headquarters concerned.

(b)  by non-operational types of aircraft with yellow under-surfaces, when large figures may be carried on the sides of the fuselage in order to meet training requirements.  These markings are to be painted on by units, after receipt from No. 41 Group.

(c)  by ambulance aircraft, which carry the "Geneva" Red Cross on a white disc of the same diameter as the yellow ring of the standard roundel, immediately aft of the roundel on each side of the fuselage.

(d)  by day fighters which carry an 18 in. band of duck-egg, blue (Sky-Type "S") right round the fuselage immediately forward of the tail plane and have the airscrew spinner painted duck-egg blue (Sky-Type "S").  These markings are to be painted on by units of No. 41 Group where necessary.

The order quoted above has been amended to AMO A687/41 issued on 28 August 1941.

A.664  Camouflage, Colouring and Markings of Aircraft

(2 July 1942)

1.  For convenience and easy reference, the camouflage, colouring and marking schemes authorised for R.A.F., naval and civil aircraft are set out in tables at appendices I, II and III, respectively, to this order.  They do not include special markings authorised by command headquarters under para. 4, sub-para. (ii) (a) below.

2.  (i) A series of diagrams is prepared for each type of aircraft, which illustrate the camouflage, colouring and marking schemes for each ro1e in which such aircraft are to he employed.  Detailed blueprints are prepared by the manufacturers, and copies of approved blueprints are obtainable on demand from the Secretary, Ministry of Aircraft Production (R.T.P.4).  In the interests of economy a general distribution is not made and blueprints are issued only on demand for workshop use.

(ii)  In the case of biplanes, the upper surfaces of the lower wing and of the floats in floatplanes are treated as upper surfaces, but the struts supporting the floats on seaplanes are to be camouflaged in the under-surface colours.  The under-surface of the upper wing is to be treated as an under-surface.

(iii)  Aircraft in operational training units, air fighting development units, Fighter Interception Unit, No. 2 School of Army Co-operation, the Central Gunnery School, meteorological flights, heavy glider conversion units and other special units of operational training unit category are to conform to the normal operational colour scheme for the role of the aircraft.  Heavy types of operational aircraft used for advance training purposes may also conform to the normal operational scheme for the role of the aircraft.

(iv)  American types of aircraft will be seen in both U.S. Army Air Corps and U.S. Navy Air Corps camouflage and colouring schemes carrying British markings.  British types of aircraft will be seen in British camouflage and colouring schemes carrying American markings.

3. Camouflage - (i) The temperate land scheme consists of dark green and dark earth.

(ii)   The temperate sea scheme consists of dark slate grey and extra dark sea grey.

(iii)   The day fighter scheme consists of dark green and ocean grey.

(iv)  The desert scheme consists of dark earth and middle stone.

4. Code letters and Special markings - (i) In addition to national markings, code letters are carried by service types in operational units and operational training units.  The two code letters, and one letter to indicate individual aircraft, are to be painted in the appropriate colour and placed before and behind the roundels on the fuselage, except that on Havoc aircraft the aircraft letter is to be placed immediately forward of the leading edge of the main plane and the squadron code letters forward of the roundels.  The code and individual letters may be placed two before and one behind the roundels or vice versa.  The letters are to be 48 in. high and are to be made up of strokes 6 in. wide.  Smaller letters are to be used only when the space available makes such a course unavoidable.  These letters are to be painted on by units after receipt of the aircraft from the maintenance group concerned.