Kawasaki Ki-45

[aizenns 3,591]

Note: The "Ki-45" that already in game is NOT a Ki-45: Ki-numbers of Type 2 Two-Seat Fighter is "Ki-45 Kai".

 

川崎 キ-45 試作複座戦闘機

Kawasaki Ki-45 Experimental Two-seats Fighter

 

History

In 1937, Army Aircraft HQ order twin engine fighter that affected by other countries heavy fighters. Nakajima, Kawasaki and Mitsubishi join this competition and they design Ki-37 (Nakajima), Ki-38 (Kawasaki) and Ki-39 (Mitsubishi). But there designs did not have enough specifications so there design ended only mock-up.

Secondary IJA order to Kawasaki new two-seat fighter, Ki-45.

Required specification of Ki-45 was below:

• Max speed: 540 km/h at 3,500 m
• Cruise range: cruising 350 km/h in 4 hours 40 minutes + max speed 30 minutes
• Armament: 2x front gun, 1x front cannon, 1x rear gun

Chief designer of Ki-38/Ki-45 was Imachi Isamu. Design of Ki-45 started in January 1938, and design completed in October 1938. First prototype plane completed in January 1939. 1st prototype and 2nd prototype equip Nakajima Ha-20 Otsu that based Bristle Mercury. Max power was 820 HP at 3,500 m but actually it broke or bad condition frequently. 3rd prototype that built March 1939 have electric motor moved gear folding mechanism and large air intake on center of spinner but bad condition of engine still continued. Also they often cause nacelle stall. By the wind tunnel test, they find when one engine rotate reverse and it solve so they decide prototype production of reverse rotation model of Ha-20 Otsu, but Ha-20 Otsu was not adopted so it was not built. Temporarily they add slit on wing near nacelle and that issue slightly improved.

In April 1940 they replace engine from Ha-20 Otsu to Ha-25 since 7th prototype. Also cowering shape changed from shape with warts to NACA type and spinner become small one. It called "No.1 Specification Improving Plan" (性能向上第一案型). In first flight of 7th prototype it cause fatal nacelle stall because pilot open cower flap maximally and it cause hard landing. But after repair it have good specification in test flight so engine of 4th, 5th and 6th prototypes replaced to Ha-25, too.

Also max speed of Ki-45 with Ha-20 Otsu was only 480 km/h, but max speed of Ki-45 with Ha-25 was improved to 520 km/h.

Finally, they build 3 prototype with Ha-20 and 8 additional prototype with Ha-25 (total 11), but this plane was not adopted because mobility of Ki-45 inferior to Ki-10 and Ki-27, and its max speed did not reached to required one.  

But this project left lots of experience, and IJA order third project, No.2 Specification Improving Plan of Ki-45 to Kawasaki: "Ki-45 Kai". Kawasaki change chief designer from Imachi to Doi Takeo. He was chief designer of Ki-48, and he use experience of design of Ki-48, and common design part of Ki-45 and Ki-45 Kai is only rear swing MG mount and engine. The Ki-45 Kai was adopted to Army as "Type 2 Two-seats Fighter" and it get nickname "Toryu" (Dragon Slayer).

 

Pros & Cons

Pros

• Able to use Ho-3 Experimental 20 mm cannon
• Curious engine nacelle design
• Smaller than Ki-45 Kai

Cons

• Slower than Ki-45 Kai
• Flight model will not be good.

 

Photos

You can find variation of Ki-45s when look around engines.

Quote

1st Prototype

Quote

2nd Prototype

Quote

3rd Prototype

Quote

Ki-45 with Ha-25

 

Drawings

Spoiler

Quote

Quote

Upper: 1st prototype

Center: 2nd prototype

Lower: 3rd prototype

Quote

Ki-45, 2nd prototype

Quote

1st Improving plan

 

 

Specification

• Ki-45
  • Engine: Ha-20 Otsu
    • 820 HP at 3,900 m
    • 790 HP at take off
  • Propeller: Constant seed variable pitch, 3 wings
    • Diameter: 2.70 m
  • Width: 14.50 m
  • Length: 10.26 m
  • Height: 3.57 m
  • Wing area: 29.0 m²
  • Own weight: 2,500 kg
  • Loading: 1,250 kg
  • Full load weight: 3,750 kg
  • Wing loading: 146.0 km/m²
  • Power weight ratio: 2.58 kg/HP
  • Fuel loads: 1,250 l
  • Max speed: 480 km/h at 4,000 m
  • Climbing time: 10 minutes 12 seconds to 5,000 m
  • Cruise range: 1,750 km
  • Armament
    • Front fixed machine gun: 2x 7.7 mm machine gun
    • Front fixed cannon: 1x 20 mm Ho-3 Experimental Auto-Cannon
    • Rear flexible machine gun: 1x 7.7 mm machine gun
• Ki-45 I
  • Engine: Ha-25
    • 970 HP at 3,400 m
    • 1,050 HP at take off
  • Propeller: Constant seed variable pitch, 3 wings
    • Diameter: 2.80 m
  • Width: 14.50 m
  • Length: 10.26 m
  • Height: 3.57 m
  • Wing area: 29.0 m²
  • Own weight: 3,150 kg
  • Loading: 1,250 kg
  • Full load weight: 4,400 kg
  • Wing loading: 160.2 km/m²
  • Power weight ratio: 2.33 kg/HP
  • Max speed: 520 km/h at 3,500 m
  • Armament
    • Front fixed machine gun: 2x 7.7 mm machine gun
    • Front fixed cannon: 1x 20 mm Ho-3 Experimental Auto-Cannon
    • Rear flexible machine gun: 1x 7.7 mm machine gun

 

Note: I can't find good source about machine guns of this plane is 7.7 mm or 7.92 mm.

 

Sources

Quote

 

野沢正 (1982) ｢日本航空機総集 第4巻 川崎編｣ 出版協同社, pp.117-129

Nozawa Tadashi (1982) "Encyclopedia of Japanese Aircraft, vol.4, Kawasaki" Shuppan Kyodo Sha, page 117-129

https://military.sakura.ne.jp/ac/ki45.htm

https://ja.wikipedia.org/wiki/キ38_(航空機)

https://ja.wikipedia.org/wiki/キ45_(航空機)

 

 

 

[aizenns 3,591]

_

[Princess_Pinch 5,625]

Open for discussion. (`･ω･´)ゞ

[NoodleCup31 8,824]

A Japanese twin engine fighter?

NAAAAAAAAAAAAAANIIIIIIIIIIIIIIIIIIIIII?

[Milocat 4,857]

Sure, the early Ki-45 would be a good addition to the game.  +1.

 

Voted for regular tree at 1.7.