No. 4 Squadron RAF

No.4 (Reserve) Squadron, (previously known as No. 4 Squadron, sometimes written as No. IV Squadron) of the Royal Air Force operates the BAE Hawk T2 in the training role from RAF Valley.

Formation and First World War
No. 4 Squadron formed at Farnborough in 1912 as part of the Royal Flying Corps. Operating a miscellaneous mixture of aircraft including early Royal Aircraft Factory B.E.2s and Breguet biplanes, it quickly moved to Netheravon where it remained until the outbreak of the First World War. The more useful aircraft in its inventory were sent to France under the command of Major G H Rayleigh on 16 August 1914, to carry out reconnaissance in support of the British Expeditionary Force. On 19 August Lieutenant G. W. Mapplebeck flew the squadron's first mission over France, a reconnaissance flight searching for German cavalry in the vicinity of Gembloux, Belgium. Other aircraft remained in England to carry out anti-Zeppelin patrols.

It was reinforced on 20 September by the personnel who had remained behind in England, forming C Flight, equipped with Maurice Farman "Shorthorns". It concentrated on the reconnaissance role, standardising on the Royal Aircraft Factory B.E.2 in 1916. In the Battle of the Somme, 4 Squadron flew contact patrols keeping track of the position of advancing troops at low level, in addition to more regular reconnaissance and artillery spotting missions. It re-equipped with the Royal Aircraft Factory R.E.8 in June 1917, in time to take part in the Battle of Messines and the Battle of Passchendaele. It remained equipped with the R.E.8 until the Armistice with Germany on 11 December 1918 ended the fighting. It returned to the United Kingdom in February 1919, disbanding in September that year.

Between the wars
No 4 Squadron reformed on 30 April 1920 at Farnborough, equipped with Bristol F.2 Fighters. Part of the squadron moved to Aldergrove near Belfast in November 1920 as a result of the Irish War of Independence, moving to Baldonnel Aerodrome near Dublin in May 1921, before rejoining the rest of the squadron at Farnborough in January 1922. Not for the last time, 4 Squadron deployed on Royal Navy aircraft carriers when they sailed to Turkey on HMS Ark Royal and Argus during the Chanak crisis in August 1922, returning to Farnborough in September 1923. When the 1926 General Strike broke out, No. 4 Squadron's aircraft were used to patrol railway lines to deter feared sabotage.

It replaced its elderly Bristol Fighters with new Armstrong Whitworth Atlas aircraft, which were purpose designed for the squadron's Army co-operation role, in October 1929, while these in turn were replaced by Hawker Audaxes in December 1931. In February 1937 it moved from Farnborough to RAF Odiham, soon re-equipping with the Hawker Hector, a more powerful derivative of the Audax. In January 1939, it discarded its Hector biplanes in favour of the new monoplane Westland Lysander.

Second World War
Shortly after the outbreak of the Second World War in 1939, the squadron moved to France as part of the British Expeditionary Force. Following Germany's invasion of France and the Low Countries on 10 May 1940, 4 Squadron was frequently forced to change bases by the approach of the advancing German armies, being withdrawn to the UK on 24 May. Losses had been heavy, with 18 aircrew killed, while 60% of the groundcrew were lost. It continued in the coastal patrol and air-sea rescue role while training for its main army co-operation role after returning to the UK.

In 1942 the Squadron changed its mission from the traditional Army Co-operation role, where it would operate fairly low-performance aircraft from airstrips close to the front-line, to that of fighter-reconnaissance, receiving the more modern Curtiss Tomahawk and North American Mustang, soon settling on the Mustang, flying low-level attack and reconnaissance flights against targets on the continent. In August 1943, it joined 2 Tactical Air Force in support of the planned invasion of Europe, changing to the pure reconnaissance mission in January, and replacing its Mustangs with Mosquito PR.XVI and Spitfire PR.XIs. It discarded its Mosquitoes in June, moving to France in August, and briefly supplementing its Spitfires with a few Hawker Typhoons for low-level reconnaissance. It retained its Spitfires at VE Day, moving to Celle in Germany to carry out survey operations in support of the British Army of Occupation until it was disbanded on 31 August 1945.

Post War operations
The squadron reformed the next day by renumbering 605 Squadron, a light bomber squadron equipped with Mosquitoes based at Volkel in the Netherlands. It re-equipped with de Havilland Vampire fighter-bombers in July 1950, replacing them with North American Sabres in October 1953. The Sabres were discarded in favour of the Hawker Hunter in July 1955, retaining these until it disbanded at RAF Jever on 31 December 1960.

Again, the squadron was not allowed to remain dormant for long, as it reformed on 1 January 1961 by renumbering No. 79 Squadron RAF, flying Hunter FR.10s in the low-level reconnaissance role. It re-equipped with the Hawker-Siddeley Harrier in 1970, first flying them from RAF Wildenrath in West Germany. It moved on to RAF Gütersloh in 1977.

The squadron operated the Harrier until the final withdrawal of the type, receiving numerous upgrades and new versions over the years. In April 1999, the squadron left Germany to move to RAF Cottesmore.

On 31 March 2010, No. 4 Squadron disbanded and reformed as No. 4 (Reserve) Squadron at RAF Wittering, taking over from No. 20 (R) Squadron as the Harrier Operational Conversion Unit. As a result of the 2010 Strategic Defence and Security Review, the squadron disbanded in January 2011, only to reform on 24 November 2011, when No. 19 (R) Squadron, operating the BAE Hawk T2 from RAF Valley in the tactical weapons training role, was renumbered.

Aircraft operated

 * Breguet Type III
 * Cody V biplane
 * Avro 500
 * Farman MF.11
 * Voisin III
 * Morane-Saulnier H
 * Bristol Scout
 * Martinsyde S.1
 * Caudron G.III
 * Royal Aircraft Factory B.E.2
 * Royal Aircraft Factory R.E.8
 * Bristol F.2 Fighter
 * Armstrong Whitworth Atlas
 * Hawker Audax
 * Hawker Hector
 * Westland Lysander
 * Curtiss Tomahawk
 * North American Mustang
 * de Havilland Mosquito
 * Supermarine Spitfire
 * de Havilland Vampire
 * North American Sabre
 * Hawker Hunter
 * Hawker Siddeley Harrier GR.1 GR.3
 * BAE Harrier II GR7 GR7A GR9
 * BAE Hawk T2

Commanding officers
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