Standard fighter for both IJN and IJA.

The Imperial Navy may have been irked that the Army had it's own subs, carriers and such, but it was more out of nessecity than politics. The IJN was not providing enough support to the Army for their logistics, so this was their work-around.

You might find this interesting to know that the U.S. Army had a massive number of watercraft in WWII, far more than the IJA.
While they didn't have carriers (the USN was far more cooperative in transporting active aircraft), they also had freighters, troopships, aircraft/seaplane repair ships, landing craft, tugs, minelayers/minesweepers and much more.

GrauGeist said:

You might find this interesting to know that the U.S. Army had a massive number of watercraft in WWII, far more than the IJA.
While they didn't have carriers (the USN was far more cooperative in transporting active aircraft), they also had freighters, troopships, aircraft/seaplane repair ships, landing craft, tugs, minelayers/minesweepers and much more.

Click to expand...

This I didn't know.

GrauGeist said:

You might find this interesting to know that the U.S. Army had a massive number of watercraft in WWII...While they didn't have carriers

Click to expand...

The US Army did operate from carriers, but still with USN crews.

The saga of the seasick US Army Piper Cubs on the Navy's smallest aircraft carriers.

Perhaps a place for Japan to start would be something akin to the USMC air command?

Admiral Beez said:

The US Army did operate from carriers, but still with USN crews.

Click to expand...

Like I mentioned, the USN was an asset to transporting USAAF "fly-off" types rather than a hindrance like in Japan's case.
Crated aircraft were either transported to their destination by USN, Merchant Marine or Army ships, depending how soon they were needed and what (who, rather) was available to do so in the time frame needed.

Absolutely fascinating, thanks to you both

There are minor problems in rationalising the IJAAF and the IJNAF. For example, the throttles moved in opposite directions and radios, gunsights and just about everything else are different.

Using the same guns would involve some problems. The Navy's Type 99 cannons could not easily be synchronised, so would not fit to any Army single engined fighter. The Army's Ho-5 cannon was developed rather late and threw by far the lightest 20 mm shell of WW2. Thus the Army may have to accept the Type 99-II and, hopefully, the extra resources will lead to a Model 5 with a belt being developed earlier. Both services liked the Browning mechanism but the Army lightened the gun to fire the Italian (Vickers) 12.7 mm ammunition whilst the Navy simply used its French 13.2mm ammunition that it was using for AA and produced a gun very similar to the American M2. As the Army was well ahead with some guns produced in 1941 compared to 1943 for the Navy, the Army's gun could be accepted by both services.

A limited rationalisation could start in 1940 when the Army orders the A6M2 as its fighter and the D3A1 instead of the Ki-51 whilst the Navy buys the Ki-46 as its land based reconnaissance aircraft. Next year, the Navy orders the Ki-44 instead of developing the J2M, which would free Mitsubishi to work on the A7M and raise the priority of their A20 or Ha-211 or MK9 or Ha-43 in the unified system. Possibly Mitsubishi might design the Ki-67 for both services around the Ha-211/Ha-43 rather than the Ha-104/Ha-42 to again increase the priority of the Ha-43.

None of this will change events greatly. The Army will be rather more effective over Malaya and the NEI because they will have more modern fighters with long ranges. The Navy's C6M (AKA Ki-46) might find the USN at Coral Sea especially if the Navy insists on the extra fuel tanks of the Ki-46 III from the start. Rabaul might be defended by Ki-44 units as well as Zeros, making attacks rather more costly.

However, even if the A7M2 is ready by mid 1944, the declining quality of Navy pilots will reduce its impact and the USN will still win the Battle of the Philippine Sea and subsequent campaigns. The main consequence of everything will be that we fan boys will be less dismissive of the Japanese command structure.

Now that I think about it,If the IJA adopted G3M in 1935 they wouldn't need to buy Italian Br.20.
Although G3M might not be as survivable as Br.20 and Ki-21.

cherry blossom said:

There are minor problems in rationalising the IJAAF and the IJNAF. For example, the throttles moved in opposite directions

Click to expand...

Really? So, the throttle on the IJN's Nakajima B5N is the opposite to the IJAF's Nakajima Ki-43? You'd figure that Nakajima, for example would settle on one throttle control lever and mechanism.

The French Grumman G-36 that the British received had to be modified, as the French had their controls reversed - like the throttle, for example: to open it (increase speed), it was pulled back, instead of being pushed foreward.

GrauGeist said:

The French Grumman G-36 that the British received had to be modified, as the French had their controls reversed - like the throttle, for example: to open it (increase speed), it was pulled back, instead of being pushed foreward.

Click to expand...

What was the thinking with this set up? Maybe so as you pulled back to climb you also pulled back to increase power? Akin, to pull towards the pilot to increase altitude and speed?

Admiral Beez said:

What was the thinking with this set up? Maybe so as you pulled back to climb you also pulled back to increase power? Akin, to pull towards the pilot to increase altitude and speed?

Click to expand...

To be 100% honest, I'm not sure.

My best guess is that the French retained the tradition from the early days of aircraft, where the throttle was controlled by a cable (kind of like the choke cable in vintage automobiles) where it was pulled to increase the throttle and pushed to decrease.

GrauGeist said:

To be 100% honest, I'm not sure.

My best guess is that the French retained the tradition from the early days of aircraft, where the throttle was controlled by a cable (kind of like the choke cable in vintage automobiles) where it was pulled to increase the throttle and pushed to decrease.

Click to expand...

Imagine if the French carried that onto other systems. Tanks where the turret rotation handle runs counter to its direction. Warships where the helm to port turns the ship to starboard, like counter steering a motorcycle.