Dornier Do Y
Do Y | |
---|---|
A Dornier Do Y of the Royal Yugoslav Air Force | |
Role | Bomber |
National origin | Germany
|
Manufacturer | Dornier Flugzeugwerke |
First flight | 17 October 1931 |
Primary user | Royal Yugoslav Air Force |
Number built | 4 |
The Dornier Do Y was a trimotor German monoplane bomber of the early 1930s designed by Dornier Flugzeugwerke (Dornier Aircraft Works) to an order by the Royal Yugoslav Air Force (RYAF). The Yugoslavs originally intended to use war reparations to pay for them, but ultimately had to use their own funds. Only a pair of aircraft were initially ordered to give the Yugoslavs experience with multi-engine bombers and Dornier failed to sell any more Do Y's. Two improved versions were subsequently built on speculation, but failed to find purchasers until the RYAF bought them in 1935.
All four Do Y's were declared obsolete in 1939 and relegated to training and transport missions. They played no role in the 1941 Invasion of Yugoslavia by the Axis Powers and were captured undamaged. The Germans decided to transfer all of them to the Air Force of the Independent State of Croatia later that year, but only one can be confirmed to have served with the Croatians.
Background
In early 1930 the RYAF decided to order some multi-engined bombers from builders with experience with multi-engine aircraft to gain experience with the type and to evaluate different models before making a decision on purchasing future aircraft. The RYAF had two main requirements: the first was that they use three
The RYAF intended to pay for them using
Dornier began construction of two improved Do Ys on its initiative the following year as the Do U and unsuccessfully attempted to sell them as
Description
The Do Y was a
The bomber was initially powered by three 450-
The
The RYAF required that the license-built 625-horsepower (466 kW) Gnome-Rhône 9Kers engines with three-bladed propellers be fitted to the Do Ym and Dornier replaced the engine nacelles with more efficient NACA cowlings to provide better cooling. In addition the wingspan of the new aircraft was reduced and the fabric covering of the underside of the wing was replaced by duralumin to eliminate the wing flutter experienced by the earlier models. A much more minor change was that more windows were added to the fuselage to improve visibility.[8][9]
Operational history
The Do Y's gave demonstrations in Austria, Hungary and Romania in early January 1932 in an unsuccessful attempt to gain more orders for the aircraft. They arrived in Yugoslavia later that month and were assigned to the 6th Aviation Regiment (6.Vazduhoplovni Puk) based at Zemun. All of the multi-engine bombers were transferred to the newly formed 261st Aviation Group (261.Vazduhoplovna Grupa) in September 1933. Later that month they participated in a parade in honour of Prince Nicholas of Romania and ferried the prince to Kraljevo and Novi Sad. On 15 October 1934, the Do Y's escorted the train carrying the body of the assassinated King Alexander I from Zemun to Belgrade. The following year the unit was redesignated as the 261st Independent Trimotor Bomber Group (Serbo-Croatian Latin: 261.Nezavizna bombarderska grupa tromotoraca).[10] The bombers finally received their bomb racks and were fitted for their defensive armament that same year,[11] although there is no photographic evidence that the Darne machine guns were ever actually mounted.[12]
The two Do Ym bombers arrived in Yugoslavia in early March 1937 and
None of the Do Y's played any part in the invasion of Yugoslavia in April 1941 and all four were captured by German forces. Both Do Y's were being overhauled and the two Do Ym bombers were parked in front of the State Aircraft Factory. Dornier documents dated 11 September state that all of the Do Y's were to be given to the Croats free of charge, but they must pay for any repairs. One of them was subsequently handed over to the Air Force of the Independent State of Croatia and was assigned to 9th Squadron in January 1942. It only made a few flights before it became a decoy at Sarajevo in mid-1944. The other three aircraft were cannibalized for spare parts and subsequently scrapped.[16]
Operators
Specifications (Do Y - 9K engines)
Data from Jane's all the World's Aircraft 1937[17]
General characteristics
- Crew: 4
- Length: 18.2 m (59 ft 9 in)
- Wingspan: 26.82 m (88 ft 0 in)
- Height: 6.3 m (20 ft 8 in)
- Wing area: 108.8 m2 (1,171 sq ft)
- Empty weight: 5,700 kg (12,566 lb)
- Gross weight: 8,500 kg (18,739 lb)
- Fuel capacity: 2,090 L (550 US gal; 460 imp gal) fuel in two wing tanks; 210 L (55 US gal; 46 imp gal) oil in three tanks
- Powerplant: 3 × Gnome-Rhône 9Kers9-cylinder air-cooled radial piston engines, 450 kW (600 hp) each at 4,050 m (13,290 ft)
- Propellers: 3-bladed metal propellers
Performance
- Maximum speed: 300 km/h (190 mph, 160 kn) at 4,000 m (13,000 ft)
- Cruise speed: 250 km/h (160 mph, 130 kn) at 4,000 m (13,000 ft)
- Landing speed: 105 km/h (65 mph; 57 kn)
- Range: 1,500 km (930 mi, 810 nmi)
- Service ceiling: 8,300 m (27,200 ft) service ceiling
- Absolute ceiling: 8,800 m (28,900 ft)
- Rate of climb: 2.7 m/s (530 ft/min)
- Time to altitude: 4,000 m (13,000 ft) in 12 minutes 30 seconds
- Wing loading: 78 kg/m2 (16 lb/sq ft)
- Power/mass: 0.15838 kW/kg (0.09634 hp/lb)
Armament
- Guns: 5x machine guns in nose, dorsal and ventral positions
- Bombs: 12 × 100 kg (220 lb) bombs carried internally in the fuselage
See also
Related lists
- List of Interwar military aircraft
Notes
Footnotes
- ^ Nikolic & Ognjevic, pp. 115, 117; Ostric, first part, p. 53
- ^ Nikolic & Ognjevic, pp. 117; Ostric, first part, p. 53
- ^ Nikolic & Ognjevic, pp. 125, 128–129, 131
- ^ Nikolic & Ognjevic, pp. 136, 138, 140–141; Ostric, last part, pp. 57–58
- ^ a b Ostric, last part, p. 58
- ^ Nikolic & Ognjevic, pp. 140–141
- ^ Nikolic & Ognjevic, pp. 139, 141; Ostric, last part, p. 57
- ^ Nikolic & Ognjevic, pp. 129, 131
- ^ Dornier, p. 121
- ^ Nikolic & Ognjevic, pp. 120, 122–123, 125
- ^ Ostric, first part, p. 55
- ^ Nikolic & Ognjevic, p. 141
- ^ Nikolic & Ognjevic, pp. 132–133
- ^ Ostric, last part, p. 55
- ^ Nikolic & Ognjevic, pp. 133–134
- ^ Nikolic & Ognjevic, pp. 133–135; Ostric, last part, p. 56
- ^ Grey, C.G.; Bridgman, Leonard, eds. (1937). Jane's all the World's Aircraft 1937. London: Sampson Low, Marston & company, ltd. p. 268c.
Bibliography
- Dornier GmbH (1985). Dornier: Die Chronik des ältesten deutschen Flugzeugwerks [Dornier: The Story of the Oldest German Aircraft Company] (in German). Friedrichshafen, Germany: Walter Biering GmbH. ISBN 3-925505-01-6.
- Nikolic, Djordie & Ognjevic, Akeksandar M. (2021). Dornier: The Yugoslav Saga 1926-2007. Lublin, Poland: Kagero Publishing. ISBN 978-83-66673-61-8.
- Ostric, Sime (June 2003). "Laid et lourde: le Dornier Do-Y en Yugoslavie (première partie)" [Ugly and Heavy: The Dornier Do-Y in Yugoslavia (first part)]. Avions: Toute l'aéronautique et son histoire (in French) (123): 50–60. ISSN 1243-8650.
- Ostric, Sime (August 2003). "Laid et lourde: le Dornier Do-Y en Yugoslavie (fin)" [Ugly and Heavy: The Dornier Do-Y in Yugoslavia (last part)]. Avions: Toute l'aéronautique et son histoire (in French) (125): 52–59. ISSN 1243-8650.