Officially at least the lower cowling, rear fuselage undersides and below the tailplanes SHOULD have been Aluminium.
Regards NIck
On the contrary. From the beginning it was Dowding's belief that it was essential that fighter aircraft were to be painted completely black and white divided down the centre line. Eventually, by his perseverance he got his way.
The first production Hurricanes were finished with Aluminium under surfaces, this practice was soon to be changed. During the mid to late 1930s, Britain was engaged in the technologically challenging task of attempting to build the world's first integrated air defence system in which fighter aircraft were only one of the vital components. Besides the aircraft themselves, a means of detecting enemy aircraft at a distance in the form of what is today called radar was developed along with a command and control system which would enable the information gathered by the radar to be passed to the fighters whilst in the air.
One of the many problems encountered in bringing this system together was how to distinguish between friendly fighters and enemy aircraft from the ground. This was necessary to allow them to be tracked over land by the Observer Corps. The early Chain Home radar transmitted its signals through 360 degrees, in order for the radar operators to distinguish the direction that the raiders were coming, the inland 180 degrees had to be blocked out electronically.
The result of this was that there was no radar coverage inland, and all the plotting information which was required for a successful interception, such as the location of the fighters in relation to the raiders once they had crossed the coast, had to be obtained visually, by the Observer Corps.
The eventual solution to the problem of distinguishing friendly fighters visually from the ground was originally suggested by the Commander in Chief of Fighter Command, Hugh Dowding. In May 1937, Dowding wrote to the Air Ministry suggesting that the undersides of fighter aircraft: should be painted in such a way as to make them easily identifiable from the ground. He suggested that the underside of one of the lower mainplanes should be finished in silver dope and the other in dull black. The idea was that in what ever degree of light this arrangement was likely to be viewed, it would always present a characteristic part coloured appearance to the observer. After some consideration by the Air Ministry it was decided that the idea should be tried out and permission for trials to begin was granted in July 1937.
The experimental work was carried out at North Weald on biplane fighters and consisted of having the underside of one mainplane painted black and the other white. Although the experiment was considered to have had mixed results the overall conclusion seems to have been that the experiment had been a success and during October 1937 Dowding wrote to the Air Ministry to inform them of the results obtained from the experiment. Whilst doing so, he suggested that with production of the Hurricane gathering pace, the undersides of the wings of these aircraft should be finished black on the port side and white on the starboard. He also suggested that to make the marking as clear as possible, the aircraft identification numbers should be omitted from the wing under surfaces.
As a result of Dowding's letter, the Air Ministry agreed that some Hurricanes could be finished in this way for the purpose of a large scale service trial and wrote to Dowding during December 1937 to inform him of the decision. As production of the Hurricane was well advanced by this time, it had not been found possible to apply the marking to early production aircraft, but it was be instituted as soon as possible without delaying production.
Whilst agreeing to the introduction of the black and white identification marking, the Air Ministry felt that it could not agree to the omission of the serial number from the under surfaces of the wings. It was felt that these markings should be retained as a deterrent to unauthorised low flying as they almost always allowed the offending aircraft and therefore pilot to be identified!
With the decision made to apply the black and white marking to a batch of fifty Hurricanes, Hawkers were advised of the fact in a letter dated 8 January 1938. They were informed that it was desired that the under surface of the port wing was to be finished in black and the starboard wing white, with the flaps and ailerons included in this colour scheme. The identification numbers on the starboard (white) side of the aircraft were to remain as they were at present, but those on the port (black) side were to be applied in white to be visible against the black background. Although the correspondence between the Air Ministry and Hawkers uses the term 'black' to describe the colour to be applied to the under surface of the port wing, it is more likely that the colour which was actually applied was Night.
Because the Air Ministry had not made it absolutely clear whether the outer wings only were to be black and white or whether the dividing line between the two colours should be on the centreline of the centre section, a sketch showing only the outer panels of the wings finished in black and white was submitted to the Air Ministry in January 1938 for their approval along with a quoted price of £5. 0. 0d. for each aircraft to be finished in this manner. When the Air Ministry raised no objections, this was how the aircraft left the production line.
In March 1938, the Air Ministry wrote to Fighter Command informing them that the serial numbers of the Hurricanes earmarked for the new under surface colour scheme were 11576 - L1625 and delivery was expected to commence before the end of the month.
Once these aircraft began to go into service during early April 1938, Fighter Command expressed a wish that all Spitfires and Hurricanes should be finished in this manner. However in June 1938, Dowding complained that the Hurricanes which had been delivered by that time had not been properly painted as he wished the black and white colours to cover the largest possible surface and to meet on the centreline. The Hurricanes supplied thus far had not been painted on the fuselage at all, leaving a silver strip between the black and white which caused the colours to blend into one another when seen from a distance, destroying the contrast.
At the same time, he suggested that the roundels on the under surfaces of home defence fighter aircraft were no longer necessary as the black and white finish would act as sufficient identification from below and the roundels only served to break up the clean expanse of black and white which was being relied upon for recognition.
The suggestion that roundels be removed from the under surfaces of Home Defence Fighter aircraft was considered by the Air Ministry, which concluded that there was no legal reason why this could not be done and in August 1938, the Director of Operations and Intelligence, wrote to Fighter Command to inform them of the decision. It was however stated that the roundels must continue to be used in the Field Force fighter squadrons.
Whilst these high level policy decisions were being taken, Hurricane deliveries to the RAF continued. No 3 Squadron was the second squadron to convert to Hurricanes, with their aircraft starting to arrive. in March 1938. Some of the aircraft initially issued to No 3 Sqn came from the experimental batch of Hurricanes which only had the under surfaces of the outer wings finished in the Night and White scheme. Similarly painted Hurricanes were also allocated to No 111 Sqn. The available photographs taken of No 3 Sqn aircraft at this time do not show any squadron markings to have been applied.
The third squadron to equip with Hurricanes was No 56, which began to receive its aircraft during April 1938. Like No 3 Sqn, No 56 Sqn also initially received Hurricanes with the experimental Night and White markings on the under surfaces..
It would appear that following Dowding's complaint in June 1938 that the black and white marking had been incorrectly applied by Hawkers; corrective action was taken on some aircraft. For example L1599 coded 'L' of No 56 Sqn appears to have had the White under the starboard wing extended across the centreline of the fuselage until it met the outer panel of the port wing which was finished in Night. The White finish was in this case also applied to the bottom of the radiator to the 60 degree tangent line, above which the radiator remained Aluminium. The carburettor air intake was left in Aluminium. How many Hurricanes had their experimental markings modified in this way is unknown as is who was responsible for making the alteration.