'Panther' (i) was the British movement of Air Vice Marshal A. Wright’s No. 1 Group of Air Marshal Sir Charles Portal’s RAF Bomber Command to France (2 September 1939).

The transfer was in direct response to the imminent British declaration of war on Germany, and on arrival the group became part of Air Vice Marshal P. H. L. Playfair’s Advanced Air Striking Force.

Before the start of World War II, the UK and France had agreed that in the event of an outbreak of hostilities the Royal Air Force’s light bomber force would be deployed to airfields in France from which it could raid targets in Germany. In order to achieve this object, the RAF Advanced Air Striking Force was created on 24 August 1939 from No. 1 Group, and its 10 squadrons of Fairey Battle light bombers were despatched to airfields in the Rheims area of north-eastern France on 2 September 1939.

The AASF was independent of General the Lord Gort’s British Expeditionary Force, and initially reported directly to the Air Ministry. However this arrangement proved to be problematic, and on 15 January 1940 the AASF was placed under the direct control of the headquarters of the British Air Forces in France command, which also assumed control of the Air Component of the BEF. Air Vice Marshal A. S. Barratt commanded the British Air Forces in France.

Political considerations prevented the use of the AASF against Germany, and the AASF therefore saw action only after the Germans had launched their 'Sichelschnitt' attack to the west on 10 May 1940.

The AASF then comprised Nos 12, 88, 103, 105, 142, 150, 218 and 226 Squadrons with the Battle, Nos 114 and 139 Squadrons with the Bristol Blenheim light bomber, and Nos 1 and 73 Squadrons with the Hawker Hurricane fighter, to be reinforced by No. 501 Squadron with the Hurricane in response to any major military action. At the start of 10 May, the AASF had 135 serviceable bombers at a moment when the French Armée de l’Air had fewer than 100 bombers, of which as many as 75% were obsolescent.

The operational instructions issued by BAFF stated that 'Bomber aircraft have proved extremely useful in support of an advancing army, especially against weak anti-aircraft resistance, but it is not clear that a bomber force used against an advancing army well supported by all forms of anti-aircraft defence and a large force of fighter aircraft, will be economically effective.' Events were to prove this to be all too true, and when used against German troops and key bridges the AASF quickly suffered heavy losses in the face of the swarming numbers of technically and tactically superior German fighters and highly effective light anti-aircraft units protecting the offensive. The Battle was known to be vulnerable to fighters attacking from below and therefore initially attacked at low level, which itself resulted in fresh problems as it brought them vulnerably close to the German light anti-aircraft batteries. For example, of eight Battle bombers despatched to attack German troops moving through Luxembourg on 11 May only one returned, its pilot having seen three Battles lost to ground fire. The Blenheim fared little better: on 12 May, seven out of the nine Blenheim bombers despatched against a German column on the road from Maastricht to Tongres road were shot down after encountering swarms of German fighters. By the end of 12 May the AASF had been whittled down to 72 serviceable bombers.

Not all missions were as disastrous: for example, on 14 May during the first AASF attack on the pontoon bridges thrown across the Meuse river at Sedan by the Germans after their initial breakthrough, 10 Battle bombers attacked from high altitude early in morning, were not engaged by German fighters and returned without loss. An attack on the bridges later in the same day, however, found that the Germans had provided fighter cover, and 40 out of 71 British aircraft were shot down.

The AASF’s original airfields were relatively close to the German line of advance to the English Channel coast after the breakthrough at Sedan, and the AASF was forced to retreat farther to the south in France. It had been anticipated that the Air Component would advance into Belgium within the 'Dyle Plan' and was therefore equipped with sufficient transport to be mobile, but this was not the case with the AASF. Some 300 trucks held by the French, but apparently unallocated, were 'borrowed' and on 16 May the AASF moved to airfields in the area of Troyes area. The two Blenheim squadrons were disbanded, the nine surviving aircraft being reallocated to the Air Component. To reduce the rate of the losses they were suffering on the bombing role, the Blenheim aircraft were from this point onward flown largely in the reconnaissance role. Two Battle units, Nos 105 and 218 Squadrons, were disbanded, their four surviving aircraft being reallocated to the six remaining squadrons which as a result of their heavy loss rate in daytime bombing were switched largely to night operations.

As a result of the deteriorating situation on the ground, the AASF was relocated to the area of Orléans and Le Mans, where it was reinforced by the Hurricane fighters of Nos 17 and 242 Squadrons, and thence to Nantes in western France. The remaining Battle aircraft returned to the UK on 15 June, while the fighters remained at Nantes or relocated to the Channel Islands to give cover to the evacuation of British units from western ports. On completion of this effort, the fighters returned to the UK on 18 June. The headquarters was disbanded on 26 June.

From the start of the German offensive in the west to its final return to the UK, the AASF had lost 229 aircraft.