To meet this threat, the French expanded their presence in North Africa. For the "Armée de l'Air" in particular, it meant being equipped primarily with U.S.-built aircraft, as had been the case in Indochina. One bomber type in the French armory was the B-26 Invader, equipped with two Pratt & Whitney R-2800 engines. The B-26 began to equip two bombardment wings from the autumn of 1956 onwards based in Algeria, starting with GB 1/91 "Gascogne", based at Oran la Senia, followed three months later by GB 2/91 "Guyenne" based at Bône in eastern Algeria. The B-26 was used in four versions. The B-26B, with a solid nose equipped with 6 to 8 12,7 mm machines-guns and B-26C glass nosed aircraft were used as bombers and for close air support with rockets, bombs and napalm. The famous Norden bombsight fitted to B-26C's could help bombardiers to aim bombs (up to two tons) on targets accurately, even in bad weather. The RB-26 photo-reconnaissance version was used by ERP.1/32 "Armagnac". In terms of organizational practice, four RB-26s were grouped alongside 16 B-26s. All these aircraft were designated to perform combat duties at a maximum range of some 600 kilometers from base with a maximum duration of 20 minutes over the target, or else up to 800 kilometers from base with a very short duration over the target. The final version was unofficially called the B-26N, a B-26C converted into a night fighter to interdict planes smuggling weapons from Tunisia. The glass nose was re-designed and equipped with British AI Mk.X radar taken from Meteor NF.11's. The B-26N was armed with two underwing gun pods with two 12,7 mm machine guns each and two rocket pods for air-to-air rockets.