Royal Air Force roundels


The air forces of the United Kingdom – the Royal Navy's Fleet Air Arm, the Army's Army Air Corps and the Royal Air Force use a roundel, a circular identification mark, painted on aircraft to identify them to other aircraft and ground forces. In one form or another, it has been used on British military aircraft from 1915 to the present.

Background

When the First World War started in 1914 it was the habit of ground troops to fire on all aircraft, friend or foe, so that the need for some form of identification mark became evident. At first the Union Flag was painted under the wings and on the sides of the fuselage. It soon became obvious that at a distance the St George's Cross of the Union Flag was likely to be confused with the Iron Cross that was already being used to identify German aircraft. After the use of a Union Flag inside a shield was tried it was decided to follow the lead of the French who used a tricolour cockade. The British reversed the colours and it became the standard marking on Royal Flying Corps aircraft from 11 December 1914, although it was well into 1915 before the new marking was used with complete consistency.
The official order stated:
The Royal Naval Air Service specified in A.I.D. SK. No A78 a five-foot red ring with a white centre and a thin white outline on the lower surfaces of the lower wings at mid span, from October 1914 until it was decided to standardise on the RFC roundel for all British military aircraft in June 1915.
With the same roundel being carried by RFC and RNAS aircraft, the use of the Union Jack was discontinued. The Royal Flying Corps and its successor the Royal Air Force have employed numerous versions of the roundel since then.
By 1917, a thin white outline was usually added to the roundel, to make the blue of the outer circle easier to distinguish from the dark camouflage colours produced by the PC.10 or PC.12 protective doping. On squadrons operating at night there was not the same need to make the marking more conspicuous, in fact it became customary to overpaint the white ring of the roundel itself – either in the camouflage finish of the aircraft as a whole, or in red. By the end of the war this had become standardised as the so-called "night roundel" of blue and red, that continued to be used on the dark NIVO green camouflage of post-war night bombers. Most RAF aircraft now had a silver finish so that the national markings were conspicuous enough without outlining. During the late 1930s, RAF and FAA aircraft were once again camouflaged, and a new outline was introduced, this time trainer yellow, and the same width as the blue and white rings.

Use by other air arms

Aside from the RAF, the Royal Navy's Royal Naval Air Service and later the Fleet Air Arm, as well as the air elements of the British Army also used the British roundels.
Many nations that had been within the British Empire and Commonwealth continued to use British roundels after achieving independence, including Canada, Australia, New Zealand, and India until nationalism demanded unique roundels for each of those countries. South Africa replaced the red with orange, Canada changed the red dot into a maple leaf, Australia changed the red dot to a kangaroo and New Zealand experimented with a gold, green and white fern inset in the red dot before settling on a red kiwi. India briefly replaced the SEAC roundel with a blue and white chakra, before adopting an orange, white and green roundel. Southern Rhodesia, the Federation of Rhodesia and Nyasaland and Rhodesia used variations on the British roundel featuring assegais before adopting a green ring with a lion and tusk on a white centre in 1970.

Roundel history

Roundel sizes

Pre-war

Up until mid-1938, roundel sizes tended to vary widely, depending on the type of aircraft; the exception to the use of type A roundels for all aircraft was seen on the overall NIVO painted night bombers which used type B roundels. Roundels used on aircraft painted in NIVO were duller than the normal colours. The size of the roundel was generally determined by the space available at the specified location, with a space of several inches around the edges. Some aircraft – primarily seaplanes, had a white outline around the fuselage roundel, even on silver doped finishes however this application was inconsistent so was probably not official. From 1929, the RAF switched to a new system of colour specifications, discarding the one used since the First World War, and as a result, the colour used for insignia changed, however the changeover period appears to have extended until at least 1932 for new production, and the old colours were not overpainted, but only gradually phased out as aircraft needed to be repainted.
During the Munich crisis of mid to late 1938, most RAF aircraft adopted green and dark earth camouflage with type B roundels of reduced sizes on all upper surfaces and the fuselage sides; though based on colour photos, these remained in the bright pre-war colours. FAA aircraft largely remained silver doped overall with type A roundels predominating. To illustrate the progression up to the end of the war the Spitfire will be used as a typical single seat-single engine fighter:
Most RAF aircraft went through similar transitions, as a result of which there was little conformity, depending on when the aircraft was built and how squadrons over painted or repainted the roundels.

Second World War

By the beginning of the Second World War on 3 September 1939, RAF roundel sizes started to show more conformity. On 30 October, all commands were ordered to change upper wing surface Type B roundels to Type A. Further instructions ordered all but fighters and night bombers to have Type A under the wing tips. This was clarified in November to the effect that only reconnaissance maritime aircraft would have the Type A on the upper wings but all aircraft would use the Type B on the sides.
A decision was made to make roundels more conspicuous and, in May 1940, the yellow outer ring was ordered to be added back to fuselage sides. Where possible, the yellow should be the same width as the blue, but on Spitfires with their narrower fuselages a thinner ring was acceptable. Also in May, an order was made to put red, white, and blue roundels on the underwings of all fighters, with an addendum that where the roundel was on a black background it should be outlined in yellow. In June, orders were given for the half black/half-white underwing scheme to be replaced by "sky" Underwing roundels were dispensed with until August when they were ordered back.
Because of the pressures of front-line service there were always exceptions to the standards set by the RAF and that deadlines were not necessarily met. Although type C and C1 roundels were meant to be in use by July 1942 some Spitfires displayed type A and A1 roundels as late as October:
Although the Spitfire is used as one example, because it was one of the few British aircraft to see front-line service before, during and after the Second World War, other aircraft types went through similar transitions. During the transition from A type to C type roundels some Hawker Typhoons displayed type C1 roundels which were modified from type A1s.
After June 1940 the official sizes for roundels were:
Type AFrom June 1940: Single and twin engine fighters, light and medium bombers, dimensions could vary but generally 50 inches for lower wings.
Type A.1From June 1940: Single and twin engine fighters, light and medium bombers 35 inches. Exceptions: Hawker Typhoon 42 inches, Westland Whirlwind 28 inches. Heavy bombers, transport aircraft 49 inches.
Type CFrom July 1942: Single and twin engine fighters, 32 inches. Not used on Night Bombers or de Havilland Mosquitoes.
Type C.1From July 1942: Single and twin engine fighters, light and medium bombers, General Aircraft Hotspur and Hamilcar gliders, 36 inches. Some night intruder Hurricanes and Spitfires had type C1 fuselage roundels in 1942. Heavy bombers, transport aircraft 54 inches.

Many variations could be seen because of the problems involved in interpreting instructions or repainting aircraft in front-line service, but most production aircraft conformed to these basic dimensions.

SEAC and RAAF

In the China/Burma/India theatre and Pacific it was thought that the red centres of RAF roundels could be confused with the red hinomaru carried by Japanese aircraft. After an RAAF No. 11 Squadron Catalina was mistaken for a Japanese aircraft by a US Navy Wildcat in the Pacific Theatre and attacked, the roundels on RAAF were modified, mostly in the field, by painting over the red with white. Often the yellow outer rings of type A1 roundels were left intact. No British or American built aircraft had factory painted SEAC style roundels; all aircraft had to be repainted, and, in many cases re-camouflaged by Maintenance Units behind the lines or by front line squadrons.
Mk VC Spitfires used by the Royal Australian Air Force over Northern Australia in October 1943 had their 36-inch type C1 fuselage roundels modified to SEAC roundels by painting out the yellow outer ring in the camouflage colours and over-painting the red centre in white. The lower wing type C roundels and upper wing type Bs were also modified by over-painting the red centres in white. The red fin stripe was also painted out with white and, in many cases the blue was extended forward 1 inch making equal widths of . RAAF Mk VIIIs had their roundels and fin flashes modified in the same ways, although some had their upper wing roundels overpainted and replaced with SEAC roundels.

Fin flash

All Royal Air Force aircraft carry a flash on the fin. This is either red/white/blue, or red/blue on camouflaged aircraft, with the red stripe nearest the leading edge. Aircraft painted anti-flash white in the nuclear strike role had a pale pink and blue flash, the same shades as the roundels, to reflect some of the thermal radiation from a nuclear explosion.
The Royal Navy and Army do not use the fin flash but have the words ROYAL NAVY or ARMY on the rear fuselage or fin instead. An exception to this was the Harrier GR7s and GR9s of the Naval Strike Wing, which carried similar markings to RAF Harriers. The fin flash can be rectangular, slanted or tapered, depending on aircraft type.
In a situation similar to that of the roundels, the fin flash was also shared with the air forces of Australia and New Zealand.
The fin flash evolved from the rudder stripes painted on the rudders of early RFC and RAF aircraft during the First World War, the markings comprising blue, white and red vertical stripes doped on the rudder. However, with the performance of aircraft increasing considerably during the 1930s, the practice of applying painted markings onto the control surfaces was discontinued because of the need to rebalance the controls – failure to do this could have adverse effects on the surface's aerodynamic balance, possibly leading to flutter of the control surface at high airspeeds. It was for this same reason that the positioning of the wing roundels was revised so that they no longer overlapped the ailerons.
In an attempt to conform to the appearance of French military aircraft, rudder stripes reappeared on aircraft of the RAF based in France, starting in early September 1939. These stripes were painted in standard RAF colours in the order blue, white, red.
Fin flashes were officially adopted in June 1940. For the first six months there was no conformity in the width or height of the stripes and they were painted to cover as much of the fin area as possible. With one or two exceptions the order was red, white, blue. In December 1940 type A fin flashes were standardised: height was 27 inches, width 24 inches, divided into three red, white and blue stripes. On some aircraft, e.g.; photo reconnaissance Spitfires the fin flash was about half these dimensions.
In July 1942, with the adoption of the type C and C1 roundels the fin flash became square for RAF fighters, the stripe widths becoming red, white and blue. There were some exceptions; RAF North American Mustangs all used fin flashes which were high by wide. In early 1944 some aircraft types were painted in a "High-altitude" camouflage scheme and adopted type B roundels and fin flashes.
The then-current RAF fin flashes were also adopted for USAAF aircraft operating alongside British and Commonwealth forces in the Mediterranean theatre in 1942, appearing on US Curtiss P-40 Warhawk fighters and North American B-25 Mitchell bombers, as well as on USAAF Consolidated B-24 Liberators flying from North Africa on attacks such as 1943's Operation Tidal Wave.

Colours

Roundel and fin-flash colours changed several times during the First World War because of severe problems with fading. The third standard would be used until the early 1930s when much brighter colours replaced the red and blue at the same time that rudder stripes were omitted. The red and blue were both duller and less saturated than later versions and varied considerably as paint was usually mixed locally. The actual switchover began in 1929 but new aircraft were still being delivered in 1932 with the earlier colours.
For the period from the early 1930s until 1938, Roundel Red was close to FS 595 21136 and the Roundel Blue was slightly lighter and brighter than FS 595 15056. Trainer Yellow was close to FS 595 23538.
Photo 2, a restored Bristol F.2 Fighter is a fairly good representation of the late interwar colours. On fabric covered aircraft these were glossy until dulled with age, even during the First World War.
In 1938, with the threat of war looming, new markings colours were introduced along with camouflage. The blue was darker, becoming similar to FS 595 25050 while the red became a slightly brownish brick-red, about FS 595 20109. The trainer yellow stayed the same shade but all colours were now matte. These colours remained standard for another eight years. To further complicate matters, old stocks continued to be used up. A series of colour photos of a Miles Master show wing and fuselage roundels in dull colours, while the fin flash remains in the bright pre-war colours, albeit with the later proportions. Other colour photos show a mixture of bright and dull colours being used on the same insignia, though all instances found have been of trainers.
Post-war colours were specified by the new BS 381 colour standard and approximate the late pre-war colours except for special cases, such as anti-flash markings and the current low visibility markings. The old blue colour, Aircraft Blue on BS381c was BS108. A new colour BS110, Roundel blue, made on Phthlalocyanine blue, was introduced in the early 1960s to improve weather fastness.

Gallery

Citations

The RAAF roundels were not SEAC type as the RAAF did not come under RAF command in the Pacific Theatre.