Number 15 Squadron, sometimes written as No. XV Squadron, was a squadron of the Royal Air Force. It most recently operated the Panavia Tornado GR4 from RAF Lossiemouth as No. XV (Reserve) Squadron. It was the RAF's Operational Conversion Unit for the Tornado GR4 which taught pilots and Weapon Systems Officers (WSO) how to fly the aircraft and what tactics to use to best exploit the performance of their aircraft and its weapons. History World War I No. 15 Squadron was first formed at Farnborough Airfield on 1 March 1915 as a Royal Flying Corps training unit, commanded by Major Philip Joubert de la Ferté. It was mainly equipped with Royal Aircraft Factory B.E.2cs, supplemented with a few Bristol Scouts, and moved to France on 22 December 1915, undertaking a reconnaissance role in support of the Army. It operated in support of IV Corps during the Battle of the Somme in summer 1916, suffering heavy losses from both ground fire and German fighter aircraft. It was praised by Douglas Haig for its work in support of the Fifth Army in the Ancre salient in January 1917. It was again heavily committed to action in support of the offensive at Arras in spring 1917. It re-equipped with the Royal Aircraft Factory R.E.8 in June 1917, retaining the "Harry Tate" (a rhyming-slang term for the aircraft) until the end of the First World War. The squadron was based at La Gorgue in northern France from 7 July until 18 August 2017. For the great tank attack at the Battle of Cambrai (November–December 2017), No.15 Squadron was specially tasked with checking the camouflaging of the troops, guns and dumps assembled before the attack. The squadron moved back to the United Kingdom in February 1919, and was disbanded at Fowlmere on 31 December that year. One of the officers who began his career in the squadron during this era was future Air Marshal Sir Charles Steele. Interwar 1919–1939 It reformed on 20 March 1924 at Martlesham Heath as part of the Aeroplane and Armament Experimental Establishment, mainly carrying out test flying of bomber aircraft. No. 15 was again reformed in 1934 at RAF Abingdon as a light bomber squadron equipped with the Hawker Hart. Its Commanding Officer of the day, Squadron Leader T W Elmhirst, DFC, instigated the squadron's tradition of writing its squadron number in Roman numerals. It received Hawker Hinds as a