[WWII] Ki-30 "Ann"/Ki-32 "Mary"

[Phaelen Bleux]

Mitsubishi Ki-30 "Ann"
In 1937, the IJA issued a specification for a light bomber to replace the aging Ki-3 biplane. Both Mitsubishi and Kawasaki submitted designs, and in 1938 the Ki-30 (Type 97 Light Bomber, or "Ann" to the Allies) was selected for production. It featured all metal-construction with fixed wheels (although retractable wheels were part of the initial design, aerodymamic studies showed that the drag produced by fixed wheels was not improved upon by the increased weight of retractable gear). The plane featured no internal intercom, with pilot and gunner communicating by means of a gosport tube. Bombs were loaded in an internal bomb bay, and the plane was armed with a fixed MG in the left wing and a trainable MG for the observer. The plane handled very well, and was liked by its pilots. It fared well in 1938 in the war against China, where it met little aerial resistance and was escorted by the Ki-27 (p. W:MP95). Later, however, the Ki-30 proved easy prey for Allied fighters, especially when no fighter escort was available. By 1942, the Ki-30 was relegated to training duties, and in the desperate last defense many Ki-30s were used for kamikaze attacks. A total of 704 Ki-30s were built.
The Ki-30 burns 35 gallons of aviation fuel per hour at routine usage. A full load of fuel and ammo (excluding bombs) costs $40. Historical range was 1,056 miles.

Subassemblies: Medium Fighter chassis +3; Light Fighter-Bomber Wings +3; 3 fixed wheels +0.
Powertrain: 708-kW aerial HP gasoline engine with 708-kW prop and 150-gallon self-sealing fuel tanks (Fire 13) [Wings and Body], 4,000-kWs battery.
Occ.: 2 CS Body
Cargo: 2 Body

Armor
Body: 2/4
Wings: 2/4
Wheels: 2/3

Weaponry:
Aircraft LMG/7.7mm Type 89 [Body:F] (500 rounds).
Aircraft LMG/7.7mm Type 89 [Body:B] (500 rounds).
882 lbs. of Bombs [Body:U].

Equipment:
Body: Autopilot, navigation instruments, medium radio transmitter and receiver (10-mile), bomb bay, universal mount for rear MG.

Statistics:
Size: 34'x48'x12' Payload: 1.09 tons Lwt.: 3.55 tons
Volume: 200 Maint.: 49 hours Cost: $16,825

HT: 8. HPs: 120 Body, 120 each Wing, 12 each Wheel.

aSpeed: 264 aAccel: 6 aDecel: 24 aMR: 6 aSR: 2
Stall Speed: 64 mph. Take-Off Run: 372 yards. Landing Run: 410 yards.
gSpeed: 226 gAccel: 11 gDecel: 10 gMR: 0.5 gSR: 2
Ground Pressure: Very High. 1/8 Off-Road Speed.

Design Notes:
Historical wing area was 329 sf. Design loaded weight was increased 12 lbs. to the historical. Design payload was 2,307 lbs; the historical value has been substituted. Fuel tankage and ammo load outs are a guess. Design aSpeed was 249 mph; the historical value is shown above. Performance calculations were based on historical values for wing area and loaded weight.

Variants:
The Kawasaki Ki-32 was submitted concomitantly to the IJA to meet the same specifications as the Ki-30. The only major difference was that Kawasaki selected a liquid-cooled 634-kW V12 engine, which proved to be temperamental and unreliable. For this reason, the IJA selected the Ki-30 over the K-32. However, by 1937, the pressing need for aircraft in the war against China resulting in the Ki-32 being ordered into production (as the Army Type 98 Singled-Engined Light Bomber, or "Mary" to the Allies), 12 months behind the Ki-30. Ironically, more Ki-32s (854) were built than the winning Ki-30 design.
Besides the engine, there were some minor variations in the Ki-32. The Ki-32 featured a smaller 660-lb. bomb bay, but featured provisions for an additional 332-lb. bomb load on wing hardpoints. Wing area was 366 sf, and loaded weight was 8,290 lbs. Range was 1,965 miles, with a top speed of 263 mph. aAccel 5, aMR 5, aDecel 21, Stall 65 mph.