The squadron was re-formed on 20 March 1924 in a very unusual role. Its home was Martlesham Heath where the Aeroplane & Armament Experimental Establishment, the premier testing organization, operated. No.15 became part of that establishment, being responsible for experimental and armament testing. It also had an operational role as a day bomber squadron with a paper establishment of de Havilland D.H.9As. In fact the squadron number was somewhat of a misnomer, for the establishment carried on its normal task, the personnel nominally being assigned to No.15 Squadron.
The real purpose of the re-forming was to boost the number of squadrons in the annual Air Estimates. Having said that, it must be admitted the nominal No. 15 Squadron managed to test 76 experimental types during its 10 years at Martlesham Heath as well as being involved in 33 different types of armament trials. It eventually disbanded in this role on 31 May 1934.
On the next day a new No. 15 Squadron was formed, in a more conventional role as a day bomber squadron. It was equipped with Hawker Harts at Abingdon. Immediately the commanding officer showed the squadron's individuality by painting the squadron number on the aircraft in Roman rather than Arabic numerals. This was repeated in the new squadron badge and, after a battle with the College of Heralds, it was agreed that the unit could now be No. XV squadron, an affectation that has been perpetuated.
Work up was slow, and it was almost a year before the Squadron could consider itself up to operational standard. It soon moved up to show its mettle against similar squadrons in what was now No.1 (Bomber) Group. In 1936 Hawker Hinds replaced the Harts, giving a marginal improvement in capabilities.
In January 1937 the unit spawned No.52 Squadron, which moved to Upwood. In May it was involved in special dive-bombing trials, making attacks at 55° angles and acquiring an especial skill at this exacting task. The squadron should have re-equipped with Fairey Battles before the year was out, but these did not come along until June 1938, by which time the unit had split again to form No.106 Squadron.
By August it was ready to take part in the home defence exercises. The rest of 1938 and 1939 were used to perfect armament training. As war approached No. XV was assigned to the Advanced Air Striking Force and moved to France on 2 September 1939 as the first RAF squadron to do so, so that it could bomb the Ruhr if Germany began an all-out attack on the UK.
In fact the squadron saw little action at all, and before the German advance in the West had returned to the UK to be re-equipped with Bristol Blenheim Mk IVs. Despite this, when 10 May 1940 came the squadron was heavily engaged. Its first full bombing mission was against Waalhaven airfield and was successful, but thereafter the squadron lost heavily on its tactical raids and after five days had only three aircraft left; these it took to the Sedan gap, and after that there were none serviceable.
It was re-equipped at Wyton in Huntingdonshire, brought up to strength, and then began raids on France and later Germany. Very quickly the squadron went over to night raids. This continued until October, when the Squadron converted to Vickers Wellingtons.
By December the squadron was operational again, taking part in the offensive against Germany by night. This continued regularly for six months, but then No. XV was involved in a bigger enterprise, literally.
It had been chosen as the second squadron to fly the first of the new generation of four-engine bombers, the Short Stirling. The first aircraft arrived on 11 April and on 30 April four aircraft bombed Berlin, Kiel and Hamburg. Operations continued in ones and twos, the first loss being on 10 May when the CO failed to return. In July the squadron began a series of daylight bombing raids on Brest, escorted by Fighter Command, but by the end of the month it was back to the night offensive.
In September it flew its first operations against Italy, Turin being the target.
During the winter of 1941 the squadron was involved in early operational trials with 'Trinity', a device which was developed into the highly successful 'Oboe', enabling blind bombing through cloud to be accomplished. The whole of 1942 saw the offensive continued unabated. The squadron was involved in the 'Thousand Bomber' raids against Cologne and Essen in May and June, and the squadron also started a fairly regular task of mining German coastal waters and canals.
New Year 1943 saw the arrival of Stirling Mk Ills giving a welcome higher cruising speed. Soon some of its aircraft were equipped with the radar navigation aid 'Gee', with which it led formations to their targets.
The squadron moved to Mildenhall in April 1943 and 'C' Flight was hived off in August to form No.622 Squadron, and the squadron again built up to full strength. The end of the year saw the end of the Stirling, by which time one of its aircraft (N3669 'LS:H'), had flown 67 operations with the squadron, a record for Stirlings.
By mid January 1944 the squadron had converted to Avro Lancasters and begun operations at the height of the Battle of Berlin which became its regular target. Equipped with 'Gee', the squadron used some of its aircraft to mark the target for the rest of the unit.
Increasingly the squadron became involved in the battle against the V-1s, bombing the sites in northern France and return-ing to daylight operations once more 15 days after D-Day. No. XV now became a specialized bombing squadron, equipped with 'G-H' to enable it to fly precision blind bombing by day and night, its aircraft so equipped being distinguished by two yellow bars across the fins. In September there was a resumption of strategic bombing, and there was no let-up until the squadron's final attack on 22 April 1945. It immediately launched into Operation 'Manna', dropping food and supplies to the beleaguered Dutch.
Immediate peacetime tasks involved flying prisoners-of-war from Europe to the UK and aerial tours of Germany for groundcrew to see the results of their crews' handiwork. In June 1946 the squadron took over some of the Lancaster B.Mk 1 (Special) aircraft that No. 617 Squadron had used to drop 'Grand Slam' bombs, and used them in trials with these bombs against the U-boat pens at Farge; by autumn the unit was reduced to six aircraft. In February 1947 the first of the squadron's Avro Lincolns arrived, and within one month the Lancasters had gone.
Some of the Lincolns were specially modified to carry 12,000-lb (5443-kg) Tallboy bombs. More trials were flown against Farge, then the squadron flew its first 'Sunray' detachment to Egypt. Whilst there it detached to Aden and flew a few operations against the Qutei tribe, which was in revolt, and thereafter the squadron followed the normal peacetime routine of a bomber squadron until disbanding at Wyton on 29 November 1950.
The squadron immediately re-formed at Marham where its new crews were working up on the Boeing Washington B.Mk 1 and, when fully converted, moved to its operational base at Coningsby. It flew Washingtons for two years, taking part in all the annual exercises and being the last squadron to drop live bombs on the range at Heligoland in February 1952.
In May 1953 the squadron went over to English Electric Canberras, and thus became part of the jet Bomber Command. It soon moved to Cottesmore, where it completed its work-up to operational pitch. After nine months there it moved again, to Honington, which became its permanent base. From here it flew all the routine operations, including 'Lone Ranger' overseas flights as far as Aden and Nairobi. With trouble brewing in Egypt in 1956, No. XV flew 56 sorties to Malta to stockpile bombs during August.
In September it deployed to Cyprus and on 31 October attacked Egyptian airfields. The squadron flew 37 missions between then and 5 November, dropping the highest number of bombs of any Canberra squadron. On 8 November the unit returned to Honington. Five weeks later it was at Malta again in case of further trouble, remaining there until the New Year. It now returned to Honington and began to run down, disbanding on 15 April 1957.
Seventeen months later No. XV was re-formed at Cottesmore as the second squadron to operate the Handley Page Victor B.Mk 1. It was February 1959 before the unit was operational, by which time it was able to provide a 4-minute scramble while on QRA. In July 1960 the squadron flew the first Victor B.Mk lAs equipped with ECM equipment to combat the radars of the USSR. Life was very active as part of the nuclear deterrent, and No. XV flew many overseas sorties, proving its ability to deploy all over the world.
This continued until April 1963, when the squadron had to convert to the low-level role as it was con-sidered to be too risky to attack the Soviet bloc at high level. In Decem-ber the squadron detached to Singapore because of the Indonesian Confrontation, and whilst there carried out armament exercises. With the passing of the nuclear deterrent to the Royal Navy the Victor B.Mk is were earmarked for tanker duties, so No. XV Squadron was disbanded on 31 October 1964.
It was not until 1970 that the squadron re-formed once more, as the RAF's second Hawker Siddeley Buccaneer squadron. This was at Honington on 1 October. After a short work-up the squadron moved to Laarbruch in Germany in January 1971 as part of RAF Germany's long-range strike wing to replace the obsolescent Canberra.
The squadron soon worked up there, developing all the techniques needed for a 'hot war' and busied itself with getting to know its opera-tional area. It has continued to fly this role in Germany, refining its techniques to keep up-to-date with differing operational threats and requirements until September 1983, when it became the first squadron in Germany to introduce the Panavia Tornado. At the time of writing the squadron is working the Tornado into RAFG operations, spearheading the eventual replacement there of all the Buccaneers and Jaguars.