Plane type: Supermarine Spitfire 

Production started with several Mk IBs which were converted to Mk VBs by Supermarine. Starting in early 1941 the round section exhaust stacks were changed to a fishtail type, marginally increasing exhaust thrust. Some late production VBs and VCs were fitted with six shorter exhaust stacks per side, similar to those of Spitfire IXs and Seafire IIIs; this was originally stipulated as applying specifically to VB(trop)s. After some initial problems with the original Mk I size oil coolers, a bigger oil cooler was fitted under the port wing; this could be recognized by a deeper housing with a circular entry. From mid-1941 alloy covered ailerons became a universal fitting.