Ki-102
Kawasaki Ki-102 Otsu attack plane
Role	Attacker, fighter, night fighter Type of aircraft
National origin	Japan
Manufacturer	Kawasaki Kōkūki Kōgyō K.K.
First flight	1944
Introduction	1944
Retired	1945
Status	Retired
Primary user	Imperial Japanese Army Air Force
Number built	238
Developed from	Kawasaki Ki-96

The Kawasaki Ki-102 or Type 4 Attack Plane (四式襲撃機, Yonshiki shūgeki-ki) was a Japanese warplane of World War II. It was a twin-engine, two-seat, long-range heavy fighter developed to replace the Ki-45 Toryu. Three versions were planned: the Ki-102 Kō day fighter, Ki-102 Otsu ground-attack and Ki-102 Hei night fighter. This aircraft's Allied reporting name was "Randy".

Design and history

The Ki-102 entered service in 1944, but saw limited action. The main type (Ki-102 Otsu) was kept in reserve to protect Japan, although it did see some limited duty in the Okinawa campaign. It was kept out of front line service because it was hoped that it would be the carrier of the Ki-148 air-to-surface guided missile when the Allied invasion of Japan occurred.

Variants

Ki-102

prototypes, three built

Ki-102 Kō

Externally similar to the Ki-102 Otsu, but with turbosuperchargers that enabled the engines to maintain their rating at higher altitudes. The 57 mm (2.24 in) cannon was swapped in favor of a 37 mm (1.46 in) cannon, and the 12.7 mm (.50 in) rear gun was deleted, 26 built.

Ki-102 Otsu

Ground-attack variant similar to prototypes, except with revised tail wheel, 207 built

Ki-102 Hei

Night fighter version with lengthened fuselage and span. Radar under a Plexiglas dome, oblique-firing 20 mm cannons, and the 20 mm cannons in the belly replaced with 30 mm (1.18 in) cannons in Schräge Musik behind the cockpit, two built.

Ki-108

High-altitude fighter prototype with pressurised cabin, two conversions from Ki-102 Otsu aircraft using the structural improvements used on the Ki-102 Hei.

Ki-108 Kai

Improved version of the Ki-108 with longer fuselage and enlarged wings. Two built.

Specifications (Ki-102 Otsu)

Data from Japanese Aircraft of the Pacific War^[1]

General characteristics

• Crew: 2
• Length: 11.45 m (37 ft 7 in)
• Wingspan: 15.57 m (51 ft 1 in)
• Height: 3.7 m (12 ft 2 in)
• Wing area: 34 m² (370 sq ft)
• Airfoil: root: NACA 24015; tip: NACA 23010^[2]
• Empty weight: 4,950 kg (10,913 lb)
• Gross weight: 7,300 kg (16,094 lb)
• Powerplant: 2 × Mitsubishi Ha112-II Ru 14-cylinder air-cooled radial engine, 1,120 kW (1,500 hp) each
• Propellers: 3-bladed constant-speed propellers

Performance

• Maximum speed: 580 km/h (360 mph, 310 kn)
• Range: 2,000 km (1,200 mi, 1,100 nmi)
• Service ceiling: 10,000 m (33,000 ft)
• Rate of climb: 11.9 m/s (2,340 ft/min)
• Power/mass: 0.417 kW/kg (0.254 hp/lb)

Armament

• Guns:
  
  • 1 × 57 mm (2.24 in) Ho-401 cannon—replaced in the 102a with a 37 mm (1.46 in) Ho-204 cannon, deleted in the 102c
  • 2 × 20 mm Ho-5 cannon in the belly—replaced in the 102c with 30 mm (1.18 in) cannon in the package, plus oblique-firing 2 × 20 mm cannon
  • 1 × 12.7 mm (0.50 in) Ho-103 machine gun (deleted in the Ki-102a and Ki-102)
• Bombs:
  
  • 2 × 200 L (53 US gal) drop tanks; or
  • 2 × 250 kg (551 lb) bombs or
  • 1 × Kawasaki Igo-1b guided missile