[1] 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 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.

His Halberstadt was painted bright blue[1] – 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.

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.

[4] Manfred von Richthofen flew a red Halberstadt D.II for a few weeks in March 1917, after the spar of the lower wing of his Albatros D.III cracked in combat.

Leutnant Nebel used a set of four improvised tubular launchers, two mounted per side on the wings, with a signal rocket being fired from each tube for the unofficial trial.

Just over a week later, Leutnant Nebel used his improvised rocket armament again and blew the propeller off an Allied aircraft, causing it to crash land.

By early 1917, the FT-Versuchsabteilung was making combat trials with the radio gear with Halberstadt D.III and D.V aircraft and by late September 1917 with the famous Jagdgeschwader I unit commanded by Manfred von Richthofen, especially Jasta 4.

[2] Data from German Combat Planes,[7] Halberstadt Fighters-Classics of World War I Aviation, Volume 1[2]General characteristics Performance Armament