P.Grosz, G.Haddow, P.Shiemer Austro-Hungarian Army Aircraft of World War One

Phonix 20.19 and 20.21

  Designer Eduard Zaparka, who had joined Phonix in late 1917, was responsible for the Phonix 20.19 and 20.21 (Phonix Type 10) prototypes that used the unique wing structure invented by him (see Zaparka fighter). The 20.19 arrived at Aspern for evaluation in January 1918, performing sporadic test flights before it was returned to the factory for installation of new wings in March. On 23 May 1918, the modified 20.19 was flown in competition with three aircraft also powered by the 230 hp Hiero engine: the Phonix C.I 121.44, the UFAG C.I 161.14, and the Brandenburg C.I(Ph) 429.01. As the lightest aircraft of the group, the 20.19 reached 5000 meters (16,504 ft) in 48 minutes; the 429.01 was second with a time of 56 minutes. The 20.19 and 20.21 appeared at the July Fighter Evaluation at Aspern for inspection. In the course of load testing on 19 August 1918, the 20.19 achieved a remarkable 9.1 factor of safety. The second Zaparka prototype, 20.21, fitted with a larger fin, continued flight trials through September.
  A second climb competition convened on 20 September demonstrated the rapid progress made by the Austro-Hungarian aircraft industry. The 20.19 that four months earlier had been first was now eclipsed by four new aircraft: the UFAG 60.03, two improved Phonix C.I biplanes (121.71 and 121.82), and the WKF 80.07, even though the 20.19 had reached 4000 meters (13,124 ft) in 37 minutes. The Phonix-Zaparka aircraft were not included in the 31 August 1918 production calendar. Both the 20.19 and 20.21 were accepted at the war's end to permit Phonix to receive payment for the aircraft.

Phonix 20.19 Specifications
Engine: 230 hp Hiero
Wing: Span Upper 10.50 m (34.45 ft)
Span Lower 8.95 m (29.36 ft)
Chord Upper 1.70 m (5.58 ft)
Chord Lower 1.40 m (4.59 ft)
Gap 0.91 m (2.99 ft)
Stagger 0.70 m (2.30 ft)
General: Empty Weight 730 kg (1610 lb)
Loaded Weight 1050 kg (2315 lb)
Maximum Speed: 175 km/hr (109 mph|
Climb: 1000m (3,281 ft) in 3 min 36 sec
2000m (6,562 ft) in 8 min 45 sec
3000m (9,84-3 ft) in 16 min 48 sec
4000m (13,124 ft) in 27 min 8 sec
5000m (16,405 ft) in 48 min

E.Hauke, W.Schroeder, B.Totschinger Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918

20. Flugzeuge der Phönix-Flugzeugwerke, vormals Österr. Albatros
20.19 Phönix C Prototyp. Konstruktion Zaparka FI 230
20.21 Phönix C Prototyp für Ba C.I FI 230