H1H
Late production H1H1 on a launching trolly.[1][2]
Role	Patrol flying boat Type of aircraft
National origin	Japan
Manufacturer	Hiro Naval Arsenal
First flight	1925
Retired	1938
Primary user	IJN Air Service
Produced	1927–1934
Number built	65
Developed from	Felixstowe F.5

The Hiro H1H (or Navy Type 15) was a 1920s Japanese bomber or reconnaissance biplane flying boat developed from the Felixstowe F.5 by the Hiro Naval Arsenal for the Imperial Japanese Navy. The aircraft were built by Hiro, the Yokosuka Naval Arsenal and Aichi.^[3]

Design and development

Following licensed production of the Felixstowe F.5 for the Imperial Japanese Navy the company developed an improved version known as the H1H or Navy Type 15. The aircraft was built with three different engine types fitted, the Navy Type 15-I with a wooden hull had longer span upper wings and the Navy Type 15-II had four-bladed propellers. The H1H remained in front line naval service through the 1930s.^[1][2][3]

Variants

H1H1

Variant powered by two 450hp (336kW) Lorraine W-12 engines.

H1H2

Variant powered by either two 450hp (336kW) Lorraine W-12 or two 500hp (373kW) BMW VII engines.

H1H3

Variant powered by two 450hp (336kW) Lorraine W-12 engines.

Operators

 Japan

• Imperial Japanese Navy Air Service

Specifications (H1H1)

Data from Illustrated Encyclopedia of Aircraft^[3]

General characteristics

• Length: 49 ft 7 in (15.11 m)
• Wingspan: 75 ft 4.5 in (22.97 m)
• Height: 17 ft 0.5 in (5.19 m)
• Wing area: 1,345.53 sq ft (125 m²)
• Empty weight: 8,862 lb (4,020 kg)
• Gross weight: 13,448 lb (6,100 kg)
• Powerplant: 2 × Lorraine 12E 12-cylinder piston engine , 450 hp (336 kW) each

Performance

• Maximum speed: 106 mph (170 km/h, 92 kn)
• Endurance: 14 hours 30 minutes

Armament

• 2 × 7.7 mm (0.303 in) machine guns (one at bow cockpit and one midships)
• up to 300 kg (661 lb) of bombs