Donnet-Denhaut flying boat

The Donnet-Denhaut flying boat was a maritime patrol and anti-submarine warfare aircraft produced in France during the First World War. Known at the time simply as "Donnet-Denhaut" or "DD" flying boats, the DD-2, DD-8, DD-9, and DD-10 designations were applied retrospectively to denote the various changes in configuration made during their service life.^[1]

DD-2, DD-8, DD-9, DD-10
Role	Patrol flying boat
Manufacturer	Donnet-Denhaut
First flight	1915
Primary users	French Navy United States Navy, Portuguese Navy
Number built	ca. 1,085

Design and development

Developed in response to a French Navy requirement, these were biplane flying boats of conventional configuration with two-bay unstaggered wings, and a Salmson R9 160 hp radial engine,^[2] mounted pusher-fashion on struts in the interplane gap. The French Navy ordered some 90 aircraft in this original configuration (later dubbed DD-2), and in 1917, requested Donnet-Denhaut to redesign the aircraft to take advantage of the new Hispano-Suiza 8 engine. So equipped, the Navy ordered another 365 machines. In order to take full advantage of the more powerful engine, Donnet-Denhaut increased the wingspan by adding a third bay to the wing cellule and used the extra lift to incorporate a place for a second gunner, bringing the total crew to three. This version (later, the DD-8) became the most produced, with perhaps 500 aircraft built. The DD-8 was also known as the Donnet-Denhaut 300-hp.

Further developments added a second machine gun to each gunner's station (the DD-9) and twin engines mounted in a push-pull configuration (the DD-10). Following the war, a few military surplus DDs were remanufactured as the Donnet HB.3 and operated commercially for a time.

Operational history

Apart from French Navy service, DD flying boats were operated by the United States Navy in Europe, flying from Île-Tudy and Dunkirk to protect convoys from submarines. Some 50 aircraft of this type were purchased, and the first attack (against U-108; unsuccessful) took place on 23 April 1918.^[3]

Operators

 France

• French Navy

 Portugal

• Portuguese Naval Aviation

 United States

• United States Navy

Specifications (DD-8)

General characteristics

• Crew: Three
• Length: 10.75 m (35 ft 5 in)
• Wingspan: 16.80 m (55 ft 1 in)
• Height: 3.00 m (9 ft 10 in)
• Wing area: 53.0 m² (570 sq ft)
• Empty weight: 950 kg (2,100 lb)
• Gross weight: 1,800 kg (3,970 lb)
• Powerplant: 1 × Hispano-Suiza 8b , 149 kW (200 hp)

Performance

• Maximum speed: 130 km/h (80 mph, 70 kn)
• Range: 520 km (320 mi, 280 nmi)
• Endurance: 4 hours
• Rate of climb: 2.5 m/s (500 ft/min)

Armament

• 2 × .303 trainable Lewis guns in open cockpits at bow
• 2 × 35 kg (70 lb) bombs

See also

Aircraft of comparable role, configuration, and era

• FBA Type H
• Lohner L

Related lists

• List of maritime patrol aircraft
• List of flying boats and floatplanes
• List of World War I Entente aircraft