Aircraft / Aviation Vehicles & Artillery Small Arms Warships & Submarines Military Ranks Military Pay Scale (2024) Special Forces

Hafeli DH-4 (M.IV)

Biplane Fighter Prototype

Switzerland | 1918

"The Hafeli DH-4 failed to impress Swiss authorities when it was tested during 1918 - leaving just one prototype to show for the work."

Power & Performance
Those special qualities that separate one aircraft design from another. Performance specifications presented assume optimal operating conditions for the Hafeli DH-4 Biplane Fighter Prototype.
1 x Hispano-Suiza HS-41 8-cylinder liquid-cooled inline piston engine developing 150 horsepower driving two-bladed, fixed-pitch wooden propeller at the nose.
93 mph
150 kph | 81 kts
Max Speed
14,108 ft
4,300 m | 3 miles
Service Ceiling
186 miles
300 km | 162 nm
Operational Range
890 ft/min
271 m/min
The nose-to-tail, wingtip-to-wingtip physical qualities of the Hafeli DH-4 Biplane Fighter Prototype.
19.7 ft
6.00 m
O/A Length
32.2 ft
(9.80 m)
O/A Width
8.5 ft
(2.60 m)
O/A Height
1,433 lb
(650 kg)
Empty Weight
1,951 lb
(885 kg)
Available supported armament and special-mission equipment featured in the design of the Hafeli DH-4 (M.IV) Biplane Fighter Prototype .
1 x 7.45mm machine gun in fixed, forward-firing mounting over the nose synchronized to fire through the spinning propeller blades.
Notable series variants as part of the Hafeli DH-4 (M.IV) family line.
Authored By: Staff Writer | Last Edited: 09/14/2021 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site; No A.I. was used in the generation of this content.

Swiss aeronautics engineer August Hafeli went on to develop a series of military biplane aircraft for Swiss Air Force consideration, this after coming over from the A.G.O. concern of the German Empire. His experience in working on the German C.I and C.II twin-boom biplanes (both detailed elsewhere on this site) led to the similar Swiss-originated "DH-1" (also detailed elsewhere on this site). The move to the DH-2 saw the twin-boom concept dropped in favor of the more traditional inline arrangement and this led to the successful DH-3 armed biplane scout of 1917 - total production yielding 110 units.

Against the backdrop of World War in Europe, Hafeli continued to push designs such as the "DH-4" of 1918, another conventional biplane approach with single-engine performance and fighting function centered around an operating crew of one. This entry relied on the successes and strong qualities of the preceding DH-3 but did away with the two-man crew and its reconnaissance role.

Its construction was completed in the early part of 1918 and the fighter exhibited expected fighter qualities such as an over-under biplane wing arrangement, open-air cockpit, and fixed, wheeled undercarriage with tailskid. The fuselage was given slab sides and the engine was installed at the nose in the usual way - the Hispano-Suiza HS-41 8-cylinder, liquid-cooled engine of 150 horsepower driving a two-bladed, fixed-pitch propeller at the nose. The upper wing member had a section of its central trailing edge cut away for improved vision for the pilot.

Dimensions of the aircraft included a running length of 19.7 feet, a wingspan of 32.1 feet, and a height of 8.5 feet. Empty weight was 1,410lb against a Maximum Take-Off Weight (MTOW) of 1,950lb. Armament was a single 7.45mm machine gun fitted ahead of the pilot and synchronized to fire through the spinning propeller blades. Construction was of the typical fabric-over-wood approach of the period.

Eidgenoessische Konstruktionswerkstaette (K+W) headed manufacture of the one and only airframe completed. This example was flown in 1918 and tests were had from May until August of that year - after which the design was shown to have unsatisfactory performance and handling. K+W took the specimen back for modification and additional testing but the aircraft never flew in a meaningful way again.

As tested, the DH-4 showcased a maximum speed of 92 miles-per-hour and a range out to 190 miles - able to fly for some 4.5 hours. Rate-of-climb was 890 feet-per-minute and 6,000 feet could be reached in fourteen minutes.

Content ©MilitaryFactory.com; No Reproduction Permitted.
Global customers who have evaluated and/or operated the Hafeli DH-4 (M.IV). Nations are displayed by flag, each linked to their respective national aircraft listing.

Total Production: 1 Units

Contractor(s): Eidgenossische Konstruktionswerkstaette (K+W) / Hafeli - Swtizerland
National flag of Switzerland

[ Switzerland (tested) ]
1 / 1
Image of the Hafeli DH-4 (M.IV)
Image from the Public Domain.

Developments of similar form-and-function, or related, to the Hafeli DH-4 (M.IV) Biplane Fighter Prototype Specifications and Pictures.
Going Further...
The Hafeli DH-4 (M.IV) Biplane Fighter Prototype appears in the following collections:
Disclaimer | Privacy Policy | Cookies

2024 Military Pay Scale Military Ranks of the World U.S. Department of Defense Dictionary Conversion Calculators Military Alphabet Code Military Map Symbols Breakdown U.S. 5-Star Generals List WWII Weapons by Country World War Next

The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com. No A.I. was used in the generation of this content.

Part of a network of sites that includes GlobalFirepower, a data-driven property used in ranking the top military powers of the world, WDMMA.org (World Directory of Modern Military Aircraft), WDMMW.org (World Directory of Modern Military Warships), SR71blackbird.org, detailing the history of the world's most iconic spyplane, and MilitaryRibbons.info, cataloguing military medals and ribbons. Special Interest: RailRoad Junction, the locomotive encyclopedia.

©2024 www.MilitaryFactory.com • All Rights Reserved • Content ©2003-2024 (21yrs)