No. 21 Squadron RAF

No. 21 Squadron Royal Flying Corps was formed at Netheravon on 23 July 1915, equipped with the Royal Aircraft Factory R.E.7. After six months of training, the squadron was sent to the France in January 1916.[2] The main role for its R.E.7s was reconnaissance,[2] while it also operated small numbers of Bristol Scout Ds[3] and a single Martinsyde G.100 as escort fighters.[4] Although the R.E.7 was badly underpowered, 21 Squadron used its R.E.7s as bombers during the Battle of the Somme,[5] being the first Squadron to drop 336 lb (153 kg bombs.[6]

It discarded its R.E.7s in August 1916, replacing them by single seat Royal Aircraft Factory B.E.12s.[7] These were used as bombers, and despite being almost useless at the role,[2] as fighters.[6] In February 1917, the Squadron re-equipped again, receiving the R.E.8, and gave a good account of itself in the Corps Reconnaissance role.[2] On one day, 7 June 1917, at the beginning of the Battle of Messines, its artillery spotting was responsible for putting 72 German batteries out of action.[8] This led General Trenchard, the commander of the Royal Flying Corps in France, to describe No. 21 as "the best artillery squadron in France".[6]

In April 1918, 21 Squadron were based at Saint Inglevert.[9] After the end of the war the squadron handed over its aircraft to 13 Squadron and was disbanded on 1 October 1919.

The squadron was reformed on 3 December 1935 at RAF Bircham Newton as a light bomber squadron equipped with the Hawker Hind biplane.[2] It moved to RAF Abbotsinch, Glasgow on 22 July 1936 and transferred to No. 2 Group on 1 August that year but transferred again, this time to No. 1 Group on 6 October.[10][11] The squadron moved to RAF Lympne in Kent in November 1936.[10] By August 1938 it began to receive the more modern Bristol Blenheim monoplane and moved to RAF Eastchurch, also in Kent.[12] The Munich crisis saw the squadron mobilise in preparation for war with Germany. The squadron temporarily joined 2 Group on 27 September and moved to RAF Cottesmore, before the end of the crisis on 8 October saw the squadron return to 1 Group and Eastchurch.[13] On 1 January 1939, the squadron rejoined 2 Group, and moved to RAF Watton in Norfolk on 2 March 1939.[14]

On the outbreak of the Second World War, the squadron was converting to the Blenheim IV and so was not fully operational, mainly flying reconnaissance missions.[15][2] In May 1940, during the Battle of France it began daylight attacks on advancing German columns in the Low Countries and France, flying its first mission of the campaign on 11 May, when 11 Blenheims attacked a bridge at Maastricht for no result except for two Blenheims shot down and eight damaged.[16] From June to October 1940 the squadron operated from RAF Lossiemouth in Scotland to attack German shipping off the coast of Norway and to deter any German invasion across the North Sea.[12][17] Back in Norfolk the squadron began regular low-level attacks on enemy shipping. At the end of 1941 the squadron moved to Malta to attack Italian shipping. The squadron was disbanded in Malta on 14 March 1942.

A 21 Squadron Ventura attacking IJmuiden, in February 1943.

On the same day a new 21 Squadron was formed at RAF Bodney, still with the Blenheim, but re-equipped a few months later with the Lockheed Ventura.[18][19] It was the first RAF squadron to use the Ventura, moving to RAF Methwold on 1 November. It flew its first operational mission using the Ventura, a low-level attack by three aircraft on railway lines near Hengelo in the Netherlands, on 3 November.[19][20] On 6 December it took part in Operation Oyster, a large-scale attack by 2 Group on the Philips works at Eindhoven, with three of its aircraft being lost.[19][21] The aircraft was never really suitable for the squadron's activities and they were replaced by October 1943 with the de Havilland Mosquito.[22] The squadron turned to night raids on continental Europe; it also carried out precision daylight raids including a notable attack on Gestapo headquarters in Denmark, and involvement in Operation Jericho.

During the invasion the Squadron was flying night intruder attacks against German targets. The Squadron moved to RAF Gutersloh in December 1945. It provided courier services between Blackbushe and Nuremberg in support of the Nuremberg Trials before it was disbanded on 7 November 1947.

On 21 September 1953 the Squadron was reformed at RAF Scampton as a bomber unit with the English Electric Canberra. It was involved in many overseas detachments and was part of the forces involved in the Suez operation of 1956. It was disbanded on 30 June 1957 at RAF Waddington.

On 1 October 1958, 542 Squadron was re-numbered as 21 Squadron with the Canberra B6, and was detached to Australia in support of trials of nuclear weapons. When the tests were completed the squadron disbanded on 15 January 1959.

Formation again on 1 May 1959 at RAF Benson saw a completely different role for the squadron: it was equipped with the Scottish Aviation Twin Pioneer as a light transport squadron. It moved to Kenya in September that year, being based at RAF Eastleigh, Nairobi. It operated in support of the British Army, the King's African Rifles and the Kenyan Police. The squadron moved to Aden in June 1965, taking over the Twin Pioneers of No.78 Squadron and supplementing them with Douglas Dakotas and Hawker Siddeley Andovers. With the withdrawal of British forces from Aden the squadron was disbanded on 9 September 1967.[23][24][lower-alpha 1]

The squadron's last formation was on 3 February 1969, when the Western Communications Squadron was re-designated at RAF Andover. It provided transport for senior officers in the western part of the United Kingdom using the Devon and Pembroke. It was disbanded following defence cuts on 31 March 1976.[2][25]