Heinkel HD 14

Heinkel HD 14
Type:	Torpedo plane
Design country:	German Empire
Manufacturer:	Heinkel
First flight:	July 1925
Commissioning:	-
Production time:	1925
Number of pieces:	1

The Heinkel HD 14 is a German floatplane developed in the 1920s by Heinkel-Flugzeugwerke in Warnemünde . In-house it was also known as HT 14 ("Heinkel Torpedo Airplane"). The abbreviation HD stands for "Heinkel Doppeldecker".

development

The order to build a total of two torpedo planes came from the Swedish Navy . The company had first examined several offers and on August 19, 1924 awarded the contract to Svenska Aero , which in turn passed on the agreement to build a copy for 110,000 kroner to Heinkel. The completion of the HD 14 was completed in June 1925. The aircraft with the serial number 221 was delivered to Sweden in individual parts and handed over to the Swedish fleet yard in Stockholm via Svenska Aero , where it was assembled. Flight testing began the following July. This was followed by drop tests with an air torpedo of the type m / 03 from September 13th . It turned out that the performance of the Italian A.14 engine from Fiat was not sufficient and the decision was made to order a more powerful engine A.25 from the same manufacturer. The order was canceled in the summer of next year, however, as the Navy in the meantime tended to believe that an air-cooled drive would be better suited for this type. The trials were therefore stopped in September 1926 and the HD 14 returned to Heinkel. Instead, the Swedish client and Svenska Aero agreed to order an improved successor, which led to the development of the HD 16 . The HD 14 was returned to Warnemünde and served there for a few years as a demonstration object and also as security when applying for loans. It was also offered as a long-range reconnaissance aircraft with a flight duration of up to 18 hours, which should be achieved by installing additional tanks instead of the torpedo, or with a different engine with a Condor engine . It was not officially registered in Sweden or Germany.

construction

The HD 14 is a ungestaffelter , cantilever biplane in composite construction . The fuselage consists of a fabric-covered tubular steel frame with a square cross-section and spar boxes made of duralumin in the middle part. The engine mount is covered with removable metal sheets and is also designed to be removable. Behind it is the fire bulkhead and the crew cabin, which is equipped with two staggered seats for the pilots, followed by a cargo hold with a third seat on the rear wall. The stern can also be dismantled. The fuel tanks are located in the middle of the upper wing and under the fuselage.

The structure of the same span consists of a middle section with two-spar outer wings made of wood with a torsion handle. It is mostly covered with fabric, only the leading edges of the wing and the areas between the spars on the underside are made of plywood . Upper and lower wings are connected to each other and to the fuselage by N-stalks; further I-struts run from the fuselage to the lower wing.

The tail unit comprises the free-standing wooden horizontal stabilizer , the aerodynamically balanced elevator and rudder, and a tubular steel ailerons with fabric covering in the upper and lower wings .

The two wooden floats are not connected to each other and are attached to the hull by I and N struts. They are single-stage , keeled and have 100% reserve buoyancy.

Technical specifications

Parameter	Data
crew	2-3
span	19.0 m
length	14.65 m
height	5.65 m
Wing area	103.3 m²
Empty mass	3400 kg
Payload	2200 kg
Takeoff mass	5600 kg
drive	a water-cooled twelve-cylinder - four stroke - V engine
Type	Fiat A.14
Starting performance Combat performance Continuous performance	750 PS (552 kW) at 1700 rpm 700 PS (515 kW) at 1650 rpm 600 PS (441 kW) at 1550 rpm
Fuel supply	2120 l
Top speed	175 km / h near the ground
Cruising speed	150 km / h
Landing speed	89 km / h
Rate of climb	2.0 m / s
Rise time	8.30 min at 1000 m
Range	1800 km without payload
Summit height	4000 m
Flight duration	10.5 h
Armament	a moving machine gun a 35 cm torpedo m / 03 or 900 kg bombs

literature

• Volker Koos: Ernst Heinkel Flugzeugwerke 1922–1932 . Heel, Königswinter 2006, ISBN 3-89880-502-6 , p. 40/41 .
• Volker Koos: Aviation between the Baltic Sea and Breitling . Warnemünde sea and land airfield 1914–1945. Transpress, Berlin 1990, ISBN 3-344-00480-8 .
• Helmut Stützer: The German military aircraft 1919–1934 . E. S. Mittler & Sohn, Herford 1984, ISBN 3-8132-0184-8 , p. 183 .