Häfeli DH-3

infobox Aircraft
name = DH-3
type = Reconnaissance biplane
manufacturer = K + W



caption = Cutaway replica of a Häfeli DH-3.
designer = August Häfeli
first flight =
introduced = 1917
retired = 1939
status =
primary user = Swiss Air Force
more users =
produced =
number built = DH-3 24
DH-3a 83
DH-3b 3
unit cost =
developed from = Hafeli DH-2
variants with their own articles = The Häfeli DH-3 was an 1910s Swiss two-seat reconnaissance aircraft, built by the aircraft department of the Federal Construction Works ("Eidgenössische Konstruktions-Werkstätte", K+W) at Thun, Switzerland.

Development and design

Following the poor performance of the DH-2, August Häfeli designed an improved version the Häfeli DH-3. It was basically the same airframe as the DH-2, the upper wing had a cut-out to give a greater field-of-fire for the pivoted machine-gun. It was a two-bay of wood and fabric construction, powered by a 120 hp (89 kW) Argus As II water-cooled inline engine. Initial problems with the landing gear and the engine cooling system led to modifications. Further developments were the re-engined and improved DH-3a, and the DH-3b used for engine trials. Following successful trials with an installation of the Handley Page slats all surviving DH-3as were modified in 1932.

Operational history

On 8 January 1919 a DH-3 inaugurated the firsts Swiss air mail service between Zurich and Berne. A DH-3 aircraft failed a structural test in 1923 which caused the DH-3 to be withdrawn from service. The DH-3a following modification remained in service until 1939.

Variants

;DH-3:Initial production version with Argus As II engine, 24 built.;DH-3a:Improved version with Hispano-Suiza HS-41 8Aa engines, four aircraft ordered in 1919. A second order of 30 aircraft was placed in 1919 with licence built engines, a third order for 49 aircraft was placed in 1925. Survivors were modified at Thun in 1932 with Handley Page slats and changes to allow crew to wear parachutes.;DH-3b:Three aircraft powered by the indigenous 150 hp (112 kw) LFW 0 engine developed by the Swiss Locomotive and Machine Works were built in 1918.

Operators

;SUI

pecifications (DH-3a)

aircraft specifications

plane or copter?=plane
jet or prop?=prop

ref=The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985)

crew=Two
capacity=
length main= 26 ft 1 in
length alt= 7.95 m
span main= 41 ft 0 in
span alt= 12.50 m
height main= 10 ft 2 in
height alt= 3.10 m
area main= 409.04 m²
area alt= 38 m²
airfoil=
empty weight main= 1,587 lb
empty weight alt= 720 kg
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 2,447 lb
max takeoff weight alt= 1110 kg
more general=

engine (prop)=Hispano-Suiza HS-41 8Aa
type of prop=8-cylinder Vee piston engine
number of props=1
power main= 150 hp
power alt= 112 kW
power original=
max speed main= 90 mph
max speed alt= 145 km/h
cruise speed main=
cruise speed alt=
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main= 249 miles
range alt= 400 km
ceiling main= 14,765 ft
ceiling alt= 4500 m
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=

armament=
* one pivoted machine-gin in the rear cockpit

avionics=

References

*cite book |last= |first= |authorlink= |coauthors= |title= The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985)|year= |publisher= Orbis Publishing|location= |issn=

External links

ee also

aircontent

related=

similar aircraft=

sequence=
DH-1 • DH-2 • DH-3 • DH-5
lists=

see also=