J.Stroud European Transport Aircraft since 1910 (Putnam)

Haefeli DH 3

  The DH 3 was a two-seat reconnaissance bomber designed by A. Haefeli and ordered for the Swiss military service in 1916. A batch of 30 was laid down by the Federal Construction Works in Thun, and the first flight of a DH 3 took place on 25 June, 1917. Total production appears to have been 90 or 120.
  The DH 3 was a two-bay biplane of unequal span, and was of wooden construction with fabric covering. The first 24 production aircraft had 120 hp Argus engines, but later aircraft had a 150 hp Hispano Suiza engine. A second batch of 30 was ordered in August 1917, and 25 of these had Hispano Suiza engines built under licence by Adolf Saurer. The other five had 200 hp engines, which were developed by the Swiss locomotive factory at Winterthur. It is reported that another batch of 30 DH 3s was built as late as 1926.
  On 8 January, 1919, an experimental military mail service was opened between Zurich and Berne, using DH 3s. Bad weather interrupted the service, and only 14 return flights had been made by the end of the month. On 1 February the service was extended to Lausanne, but bad weather prevented the Berne - Lausanne sector being worked on 16 days out of the first 28. Public mail service was planned to begin on 1 May, but weather again interfered, and the first satisfactory flights took place on 5 May. From June passengers were carried, and when the service was closed at the end of October, 246 passengers and 20,348 despatches had been carried in six months.
  The DH 3 was still in service as a trainer in 1936.


Span 12:5 m (41 ft); length 8-05 m (26 ft 5 in) with Argus, and 7:95 m (26 ft 1 in) with Hispano Suiza; wing area 38 sq m (409 sq ft).

With Argus engine. Empty weight 665 kg (1,466 Ib); loaded weight 1,040 kg (2,292 Ib). Maximum speed 135 km/h (83:8 mph).

With Hispano Suiza engine. Empty weight 690 kg (1,521 Ib); loaded weight 1,080 kg (2,380 Ib). Maximum speed 145 km/h (90 mph).

Other details unknown