Before hostilities began, it had been agreed between the United Kingdom and France that in case of war, the short-range aircraft of Bomber Command would move to French airfields to operate against targets in Nazi Germany.

The AASF was formed on 24 August 1939 from the ten squadrons of Fairey Battle light bombers of 1 Group under the command of Air Vice-Marshal Patrick Playfair and was dispatched to airfields in the Rheims area on 2 September 1939.

The AASF was dissolved on 26 June, the Battles returning to 1 Group, Bomber Command, to prepare for operations against a German invasion, along with the rest of the Royal Air Force.

With no land border to defend, British resources had been concentrated on radar stations, anti-aircraft guns and increasing the number of the most modern fighter aircraft.

Army co-operation received few resources and no plans were made for RAF participation in mass land operations or the dispatch abroad of large expeditionary air forces.

[4] French strategy emphasised the defence of the national territory and Allied efforts were expected to give equal emphasis but the British refused to stake everything on the success of a defensive campaign against the Germans in France.

[1] From the spring of 1939, arrangements were made for the reception of the AASF, the defence of British bases in France, bombing policy in support of ground forces confronting a German attack in the Benelux countries, and operations against the Luftwaffe.

1 Group RAF (Air Vice-Marshal Patrick Playfair) sent its ten Fairey Battle day-bomber squadrons to France according to plans made by the British and French earlier in the year.

[15] Battle fuel tanks were to be given the French Semape coating, which easily plugged holes from rifle-calibre bullets and also gave some protection from 20 mm (0.79 in) cannon fire.

[20] On 11 October, Luftwaffe Dornier Do 17 bombers begin to cross the lines at high altitude and one flew at 20,000 ft (6,100 m) over the 1 Squadron AASF fighter base at Vassincourt Airfield, only to be shot down near Vausigny.

Reconnaissance aircraft began to cross the front line in squadron strength to benefit from greater firepower on the most dangerous part of the journey, before dispersing towards their objectives.

[42] The AASF bomber squadrons remained on the ground waiting for orders but the bombing policy established by Grand Quartier Général (GQG, French supreme headquarters) did not require the British to obtain permission.

[52] At 7:00 a.m., nine Blenheims of 139 Squadron flew from Plivot to attack a German column near Tongeren but were intercepted by fifty Bf 109s and lost seven aircraft, two of the crews returning on foot after crash-landing.

Two Battles of A Flight took off at 8:00 a.m. and climbed to 7,000 ft (2,100 m); 15 mi (24 km) short of Maastricht, the aircraft received anti-aircraft fire, surprising the crews with the extent of the German advance.

[54] During the diversion, A Flight dived over the Maastricht−Tongeren road towards the Vroenhoven bridge covered by three Hurricanes; a Bf 109 closed on the leading aircraft, then veered off towards the second Battle, which hid in a cloud.

At 1:00 p.m. 18 Breguet 693s from GA 18 with Morane 406 fighter escorts, attacked German tank columns in the area of Hasselt, St Trond, Liège and Maastricht, losing eight bombers.

[61] Fifty miles north of the AASF bases, opposite the Meuse, the crisis of the battle of France was beginning but the Allied commanders still took the threat in the Low Countries more seriously.

French apprehensions about the situation grew so intense that the Armée de l'Air decided to use obsolete Amiot 143 bombers and Barratt agreed to make a maximum effort.

[87] The AASF bombers resumed daylight operations and 33 Battles, in small flights, attacked German columns near Reims, indirectly supported by 26 Hurricanes in the area.

Attacks near Le Cateau and St Quentin could have been on French troops by mistake; poor air reconnaissance made it difficult to find German forces or their objectives.

Long-range night sorties were extremely difficult and attacks on the Meuse crossings from the AASF bases around Troyes required a 100 mi (160 km) cross-country flight.

The Allied retreats towards the Channel and North Sea coasts had multiplied the number of supply routes open to the German armies, making attacks on the Meuse crossings less effective.

At Échemines, twelve Battles set forth to bomb airfields and other targets near Laon, Guise ad St Quentin, one pilot claiming hits on a fuel dump.

The reduction in losses was marked but 17 French day bomber groups had managed to fly 300 sorties over the same period; Barrett remained reluctant to risk more Battles in daylight.

During the day, an attack on German tank, artillery and troop columns near Argueil was planned but the diversion of the Hurricanes to protect the 51st (Highland) Division led to the operation being cancelled.

In the afternoon, twelve Battles bombed a concentration of vehicles blocked at the Pont de l'Arche railway bridge south of Le Manoir, forcing German engineers repairing it to flee for cover, also for no loss.

With fuel for a range of 1,000 mi (1,600 km) in un-armoured and non-self-sealing tanks, carrying a navigator in a cabin with a poor view outside, the Battle was highly unsuitable for short-range, low altitude, tactical attacks.

[123] The German invasion demonstrated that RAF crews were not sufficiently equipped or trained for daylight tactical operations and army support; during the Battle of Arras (21 May) the BEF had received no air cover.

The AASF had made a start on becoming a flexible tactical air force; daylight operations by the Battles had more effect on the German offensive than Wellington bombers flying by night.

[128] In 2017, Greg Baughen wrote that an Air Ministry study estimated that from 5 to 15 June, the AASF Battles had flown 264 day sorties for a loss of 23 aircraft, a 9 per cent rate.