Having failed to attract the RAF with the AAC/Parnall Arrow Mk.II trainer, Arsenal Aircraft of Canada presented a similar, Merlin-powered fighter to the Royal Canadian Air Force. Canada had a pressing need for additional domestic fighters and the low strategic material content of the AAC proposal appealled to RCAF planners. However, the RCAF objected to the six-gun wing armament of the VG.33 derivative.
AAC had anticipated the armament objection and found a simple solution. The undercarriage of the Arrow derivative would simply be moved inboard (with retracted wheels almost meeting on the centre line). This allowed for a wing armament of up to eight machine guns. A bigger concern was that all available Merlin engines were allotted to Canadian-produced Hawker Hurricanes.
After consultation with the RCAF, it was decided to substitute the Allison V-1710 powerplant. Installing this engine was comparatively simple since AAC was originally meant to supply Allison-powered VG.32 fighters to the French. The new fighter, now named the AAC Ares, developed quickly and differed in detail from the VG.32 -- aside from the revised undercarriage, the Ares also introduced twin, synchronized .50" cowl guns with another pair of 'fifties' in the new inboard wing positions.
The prototype Ares F.Mk.I (top) flew with a V-1710-33 engine in late May 1941. The first production Ares, the F.Mk.IA with a six-gun wing armament, followed in September 1941. In the aftermath of the Japanese attack on Pearl Harbour, the F.Mk.IAs were quickly issued to West Coast fighter squadrons. The pressure was now on AAC to fully arm the Mk.IAs and field the eight-gunned Ares F.Mk.IB as soon as possible.
Bottom: AAC Ares F.Mk.IA (upgraded) of No.111 (Fighter) Squadron flying in defence of Vancouver harbour in late 1941.