The Kawanishi E15K Shiun, Allied reporting name “Norm”, was a Japanese single-engine reconnaissance floatplane developed during World War II. Designed by the Kawanishi Aircraft Company, it aimed to fulfill a 1939 Imperial Japanese Navy (IJN) requirement for a high-speed reconnaissance aircraft capable of operating in areas dominated by enemy fighters.
The E15K Shiun was conceived to meet the 14-Shi specification, which outlined the need for a two-seat reconnaissance floatplane with sufficient performance to escape interception by land-based fighters and a range of 800 nautical miles. Kawanishi’s design featured a low-wing monoplane configuration with a single central float and two stabilizing floats under the wings. Notably, it incorporated Japan’s first use of contra-rotating propellers, driven by a Mitsubishi MK4D Kasei 14 14-cylinder radial engine. The aircraft also introduced a retractable wingtip float system, intended to be jettisoned during combat to increase speed.
The first prototype, designated E15K1, made its maiden flight on December 5, 1941. Subsequent prototypes were developed, leading to limited production in 1943. However, the aircraft faced several technical challenges, including issues with the retractable float mechanism and engine reliability. To address these, the design was modified to include fixed stabilizing floats and a more powerful Mitsubishi MK4S Kasei 24 engine.
A total of 15 E15K1 aircraft were built, comprising six prototypes and nine production models. The first operational units were assigned to the 12th Reconnaissance Squadron of the 61st Air Flotilla in April 1944. These aircraft were deployed to Palau Island in June 1944. Despite their advanced design, the E15K1s proved vulnerable in combat. The jettisonable float mechanism often malfunctioned, and the aircraft’s performance was insufficient against newer Allied fighters. On June 15, 1944, two E15K1s were shot down by Grumman F6F Hellcats while conducting reconnaissance over the Bonin Islands. Additional losses occurred during anti-submarine patrols, leading to the disbandment of the 12th Reconnaissance Squadron on August 12, 1944.
- Crew: 2 (pilot and observer)
- Length: 11.59 m (38 ft 0 in)
- Wingspan: 14.00 m (45 ft 11 in)
- Height: 4.95 m (16 ft 3 in)
- Wing Area: 30 m² (320 ft²)
- Empty Weight: 3,165 kg (6,978 lb)
- Maximum Takeoff Weight: 4,900 kg (10,803 lb)
- Powerplant: 1 × Mitsubishi MK4S Kasei 24 14-cylinder radial engine, 1,850 hp
- Maximum Speed: 469 km/h (291 mph) at 5,700 m (18,700 ft)
- Cruising Speed: 296 km/h (184 mph) at 2,500 m (8,200 ft)
- Range: 3,371 km (2,095 miles)
- Service Ceiling: 9,830 m (32,250 ft)
- Armament: 1 × 7.7 mm Type 92 machine gun in rear cockpit
