Hardlydank
Airman 1st Class
This thread is to serve as a reference for Ki-43 variant identification. I have spent entirely too long studying photos, books, and technical drawings to figure out the variants. Hopefully this will also be of use to someone other than me.
Now, there are 3 main Ki-43 variants: Ki-43-I, Ki-43-II, and Ki-43-III. Within these are 8 subvariants. I won't be going through every single change through the sub-variants, only the ones that are relevant to identification.
Ki-43-I (Attachments #1-2)
The Ki-43-I is probably the easiest to identify. However, there is no way to distinguish the subvariants from each other. The only difference between them is the armament, so unless you can actually see the guns themselves in a photo there is no way to tell which subvariant it is. Attachments 1 and 2 show the identifiable features of the Ki-43-I
Ki-43-Ia (Ko): 2 0.30 cal machine guns
Ki-43-Ib (Otsu): 1 0.30 cal machine gun and 1 0.50 cal machine gun
Ki-43-Ic (Hei): 2 0.50 cal machine guns (used on all subsequent production variants)
Ki-43-II (Attachments #3-8)
The Ki-43-II was the biggest evolutionary step for the Ki-43. The main features introduced were a 3 bladed prop, reflector gunsight, and an upgraded engine housed under a more streamlined nose.
Ki-43-IIa Early (Ko): Attachment #3 shows the identifiable features of the Ki-43-IIa Early. Of note is the secondary oil cooler. I have outlined its shape on Attachment #3 in white. This is the only way to identify this subvariant if you can't see the oil cooler ring. The oil cooler in Attachment #5 is also outlined in white to show how the shape changed on the next subvariant, the Ki-43-IIa. The shape of it remained basically the same for the rest of the variants after the Ki-43-IIa Early. Attachment #4 shows a clearer view of the oil cooler ring.
Ki-43-IIa (Ko upgraded): Having 2 separate oil coolers turned out to be overly complex and inefficient, so this subvariant deleted the oil cooler ring and had 1 large 'honeycomb' type oil cooler under the nose. Attachment#6 shows this. Attachments #3 and #5 can be compared to see the difference in size and shape of the undernose cooler.
Ki-43-IIb (Otsu): This subvariant has a smaller forward cowling opening and had its exhaust pipes angled backwards for slightly increased thrust. Attachment #7 shows the difference in the forward cowling opening and Attachment #8 shows the angled exhaust pipe.
Ki-43-IIc (Kai): This subvariant introduced ejector exhaust stacks which further increased thrust. The main problem with identifying this subvariant is telling it apart from the next subvariant. I'll say how to tell the difference on the next subvariant section.
Ki-43-III (Attachments #9-11)
Ki-43-IIIa (Ko): This is the last subvariant. I'll be showing how to tell the Ki-43-IIc and Ki-43-IIIa apart. There are 3 ways: the machine gun blast tubes, water-methanol filling port, and cowling opening shape. The Ki-43-III's blast tubes are set further back and have a vertical profile, while the Ki-43-II's blast tubes are more forward and are angled back at about 45 degrees. The water-methanol filling port is only present on the Ki-43-III, it's located behind the pilot's seat and is a cylindrical shape sticking up from the fuselage inside the canopy. The Ki-43-II's cowling opening has a downward curve around the carburetor intake, which on the Ki-43-III is straight. Attachment #9 shows 2 of the 3 identifying features compared on both subvariants. Attachments #10 and #11 both show the water-methanol filling port.
Now, there are 3 main Ki-43 variants: Ki-43-I, Ki-43-II, and Ki-43-III. Within these are 8 subvariants. I won't be going through every single change through the sub-variants, only the ones that are relevant to identification.
Ki-43-I (Attachments #1-2)
The Ki-43-I is probably the easiest to identify. However, there is no way to distinguish the subvariants from each other. The only difference between them is the armament, so unless you can actually see the guns themselves in a photo there is no way to tell which subvariant it is. Attachments 1 and 2 show the identifiable features of the Ki-43-I
Ki-43-Ia (Ko): 2 0.30 cal machine guns
Ki-43-Ib (Otsu): 1 0.30 cal machine gun and 1 0.50 cal machine gun
Ki-43-Ic (Hei): 2 0.50 cal machine guns (used on all subsequent production variants)
Ki-43-II (Attachments #3-8)
The Ki-43-II was the biggest evolutionary step for the Ki-43. The main features introduced were a 3 bladed prop, reflector gunsight, and an upgraded engine housed under a more streamlined nose.
Ki-43-IIa Early (Ko): Attachment #3 shows the identifiable features of the Ki-43-IIa Early. Of note is the secondary oil cooler. I have outlined its shape on Attachment #3 in white. This is the only way to identify this subvariant if you can't see the oil cooler ring. The oil cooler in Attachment #5 is also outlined in white to show how the shape changed on the next subvariant, the Ki-43-IIa. The shape of it remained basically the same for the rest of the variants after the Ki-43-IIa Early. Attachment #4 shows a clearer view of the oil cooler ring.
Ki-43-IIa (Ko upgraded): Having 2 separate oil coolers turned out to be overly complex and inefficient, so this subvariant deleted the oil cooler ring and had 1 large 'honeycomb' type oil cooler under the nose. Attachment#6 shows this. Attachments #3 and #5 can be compared to see the difference in size and shape of the undernose cooler.
Ki-43-IIb (Otsu): This subvariant has a smaller forward cowling opening and had its exhaust pipes angled backwards for slightly increased thrust. Attachment #7 shows the difference in the forward cowling opening and Attachment #8 shows the angled exhaust pipe.
Ki-43-IIc (Kai): This subvariant introduced ejector exhaust stacks which further increased thrust. The main problem with identifying this subvariant is telling it apart from the next subvariant. I'll say how to tell the difference on the next subvariant section.
Ki-43-III (Attachments #9-11)
Ki-43-IIIa (Ko): This is the last subvariant. I'll be showing how to tell the Ki-43-IIc and Ki-43-IIIa apart. There are 3 ways: the machine gun blast tubes, water-methanol filling port, and cowling opening shape. The Ki-43-III's blast tubes are set further back and have a vertical profile, while the Ki-43-II's blast tubes are more forward and are angled back at about 45 degrees. The water-methanol filling port is only present on the Ki-43-III, it's located behind the pilot's seat and is a cylindrical shape sticking up from the fuselage inside the canopy. The Ki-43-II's cowling opening has a downward curve around the carburetor intake, which on the Ki-43-III is straight. Attachment #9 shows 2 of the 3 identifying features compared on both subvariants. Attachments #10 and #11 both show the water-methanol filling port.
Attachments
Last edited:
The bulges in front of the front cockpit sides on Ki-43-I are to clear the 12.7mm guns and ammo belt feed, i've been trying to find if early prototypes with 7.7mm did not have them as I think they were an afterthought in design (like Me109G-6 MG bulges!).
