Hafeli DH-1

[Des]

Gunther sent me photos of this replica Hafeli DH-1 at the Fliegermuseum in Duebendort, Switzerland. Six of these aircraft were flown between 1916 - 1919 and were a two seater reconnaissance aircraft, they were not very successful.

Des.

[Rob Hart]

A pity they weren't more successful, certainly an attractive machine. Thanks for sharing the photos.

[GHE]

Messieurs !

The HÄFELI  DH-1  (M1)   M= Militär /military

engineer: A. Häfeli , Thun/Suisse
factory: Eidgenössische (confederate) Konstruktionswerkstätte (engineering workshop) K & W, flight division; Thun/Suisse
built in:1916   - 6 machines
type: reconnaissance aeroplane  1 observer 1 pilot   service time: 1916-1919   registration markings: 241-246

armament: 1 air-cooled MG cal 0.293/7,45mm

description:
3-strutter biplane, composite construction, braced, 2-tail boom, pusher engine and airscrew, double nosegear arrangement
span: 12,80 m  length: 8,82 m  height: 3,00 m  wing area: 38,oo m2  weight empty: 750,00 kg  payload: 375,00 kg
max. take-off weight: 1125 kg

engine: licence-built ARGUS AS II (Argus Motorengesellschaft, Reineckendorf/Berlin) by Bühler Brothers, Uzwil/Suisse
weight:191 kg   11,8 litre  6 cylinders  120 hp at 1400 rpm/sea level   boost:none   borexstroke: 130mm x 140mm  compression rate: 3,7:1
airscrew:2-blade laminated pusher airscrew   diameter: 2,70m   pitch: 1,65m

Vi max. level flight: 126 km/h  78,75 mph   max climb rate: 1,50 m/sec  4,92 yds/sec   endurance:  2 hours 30 min
range: 250 km   156,25 miles

Story:
August Häfeli worked for the  firm "Aero-Werke Gustav Otto"  (they also built the first Otto-machine for the Royal
Bavarian Airforce in 1912) before he went to K&W.
At "Gustav Otto" he was in charge of the AGO C 1 aeroplane.
The Häfeli DH1 largely corresponds to the AGO machine.

The DH-1 (M1) was not successful, 3 crashed in 1917; the hook was a try to enhance braking while landing- but was too dangerous; in 1919 the remaineing 3 machines were scrapped.
Why ( and what )  flying characteristics weren't satisfying I couldn't find out.

viele Grüße, Gunther

replica built at BAMF / Buochs, Suisse and Interlaken  (between the lakes), Suisse; 29.02.1982-24.08.1985; 9710 workhours;

[GHE]

Messieurs!

Looking at the tailplane and how both are hold together one may assume that it was a "swinging" fuselage; the bond couldn't
have been as stable as on a P-38 Lightning or a DH 2 (lot of rigging to stabilize).*
It also may have been tail-heavy and take-off/landing might not be easy... .

viele Grüße, Gunther

*... the tail booms look sturdy but not the way they are fixed to the wing struts and bond together at the tail end

[Whiteknuckles]

It's an interesting looking machine, that's for sure.
The banded woodwork on the tail booms is very intriguing.

Andrew