Halberstadt D.II

https://en.wikipedia.org/wiki/Halberstadt_D.II

The Halberstadt D.II was a biplane fighter aircraft developed and manufactured
by German aircraft company Halberstädter Flugzeugwerke.

It was adopted by the Luftstreitkräfte (Imperial German Army Air Service) and
served through the period of Allied air superiority in early 1916. As the first
biplane configuration fighter aircraft to serve in combat for the German Empire,
it had begun to be superseded in the Jagdstaffeln and other early German fighter
units by the superior Albatros fighters in the second half of the year, although
small numbers of Halberstadts continued in use well into 1917.

The D.II was the production version of the experimental D.I. Key differences
between the D.I and D.II included a substantial effort to lighten the aircraft
in order to improve its performance; the latter also featured staggered wings
and the adoption of a more powerful 120 hp Mercedes D.II engine. The side and
frontal radiators that had been tried in the D.I were replaced by a wing mounted
radiator, similar to the arrangement that was later used by the Albatros D.III
and D.V. In comparison with the D.I, the pilot sat higher in his cockpit, to
improve his view over the top wing. This required a dorsal turtleback fairing
over the rear fuselage, to improve its lines.

The two bay wings were very strongly braced, but the trailing edge was composed
of a wooden member, as opposed to the wire or cable common on many of the First
World War-era German single-engined aircraft. Photographic evidence indicates
that many examples were rigged with washout on the lower wings – giving the
impression of a curved or twisted lower wing trailing edge. In some photos even
the upper wings have a similar sort of "trailing edge droop" on the fixed
section inboard of the ailerons.

Lateral control was by ailerons, but the Morane-style empennage (common not only
to Moranes, but also to the Fokker and Pfalz types of the period) was retained.
The inevitable result was extreme fore-and-aft sensitivity and poor control
harmonization. The D.II was nonetheless considered to be very manoeuvrable in
skilled hands: in particular it could reputedly be dived safely at high speed. A
single synchronised lMG 08 "Spandau" machine gun fired through the propeller
arc.

If the only performance figures available for the type are accurate, the
Halberstadt fighter's speed and climb were little better than the Eindecker's,
but it earned the respect of Allied fighter pilots and was a preferred mount of
the pilots of the early Jagdstaffeln, until the Albatros D.I became available.
Halberstadts were actually retained, or even returned to service by some pilots
during the early weeks of 1917, at a time when the structural difficulties with
the Albatros D.III first surfaced.


Role
Fighter

Manufacturer
Halberstädter Flugzeugwerke
also under license to
Aviatik
Hannoversche Waggonfabrik

Designer
Karl Theis

First flight
Late 1915

Introduction
Early 1916

Retired
1917

Primary user
Luftstreitkräfte

Produced
1916

Number built
65

Like other early German fighter types, the D.II was at first supplied in ones
and twos to the ordinary six-aircraft reconnaissance units or Feldflieger
Abteilungen of the German Air Service: then from February 1916 onward through
the summer of that year gathered into small specialised fighter units – the
Kampfeinsitzer-Kommandos or "KEK" units. When the first true fighter
Jagdstaffeln were formed in mid-1916, the Halberstadt was the best fighter
available and was used by Oswald Boelcke to demonstrate his famous pioneering
air fighting tactics (the Dicta Boelcke) to the new units (although he is also
recorded as flying a Fokker D.III at this period). His Halberstadt was painted
bright blue – one of the first documented instances of the gaudy personal
finishes applied by German fighter pilots to their mounts for the remainder of
the war.

For some reason, the Halberstadt-built D-series fighters bore no marked
IdFlieg-issued military serial numbers anywhere on their exteriors. The
licence-built Aviatik and Hannover-constructed examples of the Halberstadt
D-series fighters usually had IdFlieg-issued serial numbers on their rear
fuselage sides.

As the new Albatros fighters came into service the Halberstadts were quickly
replaced, although a few survived into early 1917. Manfred von Richthofen flew a
red Halberstadt D.II for a few weeks in February and March 1917, after the spar
of the lower wing of his Albatros D.III cracked in combat.

Variants

Aviatik of Germany built the D.II under licence. It was originally known as the
Aviatik D.I (not to be confused with their Austrian subsidiary's
independently-designed Aviatik (Berg) D.I) but was later called the Halberstadt
D.II(Av).

The Halberstadt D.III primarily differed from the D.II version in its
substitution of the Argus As.II 90 kW (120 hp) straight-six engine, which
differed from the usual Mercedes D.II powerplant in having its camshaft in the
engine block and using pushrods to operate the overhead valves, rather than
having a camshaft running atop all of the cylinders as in a single overhead cam
engine. A total of 50 D.III examples were built by Halberstadt, with the first
30 ordered in July 1916 and the last 20 ordered in August 1916.

The D.IV version, of which only three were built to an order placed in early
March 1916, changed the wing bracing layout to a single bay, dispensed with the
twin bracing struts for the "all moving" vertical tail rudder surface, and used
a Benz Bz.III 110 kW (150 hp) straight-six engine for power, with a small
conical spinner for better streamlining. Tested by IdFlieg in October 1916, this
type was rejected for further evaluation due to a poor forward field of view for
the pilot.

The D.V version was a less radical departure from the earlier D.II version and
mostly differed from the D.II, in having its four-member cabane strut structure
supporting a central panel for the upper wing, rather than both upper wing
panel's wing roots meeting along the centreline of the aircraft, for better
forward pilot vision. It also used the D.III version's Argus As.II engine and
changed the mounting position of the aircraft's 7.92 mm (.312 in) lMG 08 machine
gun from the right to the left side of the nose. A total of 57 D.V aircraft were
built, from orders placed in October 1916 and January–June 1917, with 31 of
these being sent to Germany's ally in the Central Powers, the Ottoman Empire.

Specifications (D.II)

General characteristics
Crew: 1
Length: 7.3 m (23 ft 11 in)
Wingspan: 8.8 m (28 ft 10 in)
Height: 2.66 m (8 ft 9 in)
Wing area: 23.6 m2 (254 sq ft)
Empty weight: 519 kg (1,144 lb)
Gross weight: 728.5 kg (1,606 lb)
Powerplant: 1 × Mercedes D.II 6-cylinder water-cooled in-line piston engine, 90
kW (120 hp)
Propellers: 2-bladed fixed-pitch propeller

Performance
Maximum speed: 150 km/h (93 mph, 81 kn)
Range: 250 km (160 mi, 130 nmi)
Service ceiling: 4,000 m (13,000 ft)
Time to altitude:

1,000 m (3,281 ft) in 3 minutes 30 seconds
2,000 m (6,562 ft) in 8 minutes 30 seconds
3,000 m (9,843 ft) in 14 minutes 30 seconds
4,000 m (13,123 ft) in 22 minutes 30 seconds
5,000 m (16,404 ft) in 38 minutes 30 seconds

Armament

Guns: 1 × forward-firing 7.92 mm (.312 in) lMG 08 "Spandau" machine gun




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