This list is a guideline to the basic recognition features on the P-39 models. Throughout its service life, the P-39 saw very little change, especially the D through Q models. Most visual changes amount to different armament configurations, nose gun vents, or exhaust stacks. Some models can only be distinguished by their serial number.
For the model builder, this will hopefully simplify the process of trying to decide what options go with which model. (Sometimes manufacturers instructions aren’t even correct!)
Of course, some items may have varied slightly during production even within the same model, so if possible, a photograph is the best reference.
Exhausts: One some aircraft with 6 exhausts, “fish tailed” exhausts were used. Check references.
Gas Vents: These vents, which appear as small, angular bumps on the cowl just aft of the prop were added to allow gases from the guns to escape and not get into the cockpit
Nose wheel: Originally a “fat” nosewheel was used, but eventually a change to a more streamlined, “low profile” tire was used. Once larger props were installed, a larger nosewheel was used to give additional ground clearance. Check photographic references.
|Model||Exhausts||Cannon||Wing guns||Prop||Gas vents||Nose wheel||Notes|
|P-39C||6||37mm||none||3 bladed||N||Standard||2x .30 & 2 .50 in the nose; No canopy frame directly over pilot’s head; no vertical fin fairing|
|P-39D||6||37mm||4x.30||3 bladed||N||Standard||On some models, no canopy frame directly over pilot’s head, check photos if possible|
|Airacobra I/P-400||12||20mm||4x.30||3 bladed||N||Standard||On some models, no canopy frame directly over pilot’s head, check photos if possible|
|P-39J||12||37mm||4x.30||3 bladed||N||Standard||Identical to F except for engine|
|P-39K||6||37mm||4x.30||3 bladed||Y||Standard||Identical to D-2 except for engine and prop maker|
|P-39L||6||37mm||4x.30||3 bladed||Y||Streamlined||Identical to K except for prop maker|
|P-39N||6||37mm||4x.30||3 bladed||Y||Large||Streamlined nosewheel for first 166 aircraft, afterwards a larger nose wheel was used because of a larger prop installation|
|P-39Q||6||37mm||2x .50 pods||3 bladed||Y||Large||Russian aircraft generally had the gun pods removed|
|P-39Q-21 & -25||6||37mm||2x .50 pods||4 bladed||Y||Large||Russian aircraft generally had the gun pods removed|