Lohner B.II

Lohner

Industry	Aircraft manufacturing
Founded	1910s
Headquarters	Austria-Hungary
Products	Military reconnaissance aircraft

The Lohner B.II, initially known as Type C, was a reconnaissance aircraft built for military use in Austria-Hungary during the First World War. It evolved from the earlier pre-war Lohner B.I model, incorporating modifications requested by the Austro-Hungarian Army, while retaining key structural elements such as its distinctive swept-back wing design.

Design and development

Designed to enhance performance over the rugged Austrian Alpine region, the Type C featured an elongated fuselage, increased wingspan, and a reinforced undercarriage. The original Type B's Austro-Daimler powerplant was replaced with a lighter Hiero engine that delivered slightly reduced horsepower. However, the increased wingspan introduced structural challenges; during stress tests, the prototype's wings failed. A subsequent prototype with strengthened wing structures was approved by the Army in August 1913, leading to an order for 24 additional units. Shortly after production commenced, an in-flight wing failure occurred on a Type C, prompting a fleet-wide grounding. Efforts to reinforce the wing framework were undertaken under Professor Richard Knoller's supervision but remained incomplete when hostilities began. Despite this, six Type Cs were rapidly returned to service, and restrictions on the others were soon lifted. Operational experience revealed that the aircraft was underpowered and structurally fragile, resulting in its reassignment to non-frontline duties. In February 1915, the Luftschiffabteilung updated its designation system to align with German standards, renaming Type C as B.II. Later that year, all surviving B.IIs received upgraded wings with enhanced strength, and both B.I and B.II models were licensed for production at Flugzeugwerk Fischamend to serve primarily as training aircraft.

Throughout the year, subsequent variants such as the B.III, B.IV, B.V, and B.VI emerged, each equipped with different engines. Production quantities remained limited; however, the B.III and B.IV were also manufactured by the newly established Ufag company in Albertfalva, Budapest, which had been set up specifically to produce these Lohner designs. Continued refinement culminated in the development of the Lohner B.VII by year's end.

Variants

B.II

Known as the Lohner Type C, this production model was equipped with a 63 kW (85 hp) Hiero engine, with a total of 96 units constructed.

B.II(U)

Designated Series 12.4 and manufactured by UFAG (Ungarische Flugzeugfabrik Abteil Gesellschaft / Ungarische Flugzeugwerke Aktien Gesellschaft), this variant saw a production run of 18 aircraft.

B.III

Referred to as the Lohner Type E, this version featured either a 75 kW (100 hp) Mercedes engine or a 90 kW (120 hp) Austro-Daimler powerplant.

B.III(U)

Identified as Series 14.5 and produced by UFAG, this model was powered by a 75 kW (100 hp) Austro-Daimler engine, with eight units built.

B.IV

This version incorporated an updated undercarriage design and was fitted with a 75 kW (100 hp) Mercedes engine; only one was manufactured.

B.IV(U)

Produced by UFAG as Series 15.5, this variant had eight aircraft completed.

B.V

Featuring a 100 kW (140 hp) Rapp Rp II engine, this model saw six examples constructed.

B.VI

Closely resembling the B.V, this version had a production total of eighteen aircraft.

Operators

Template:Country data Austria-Hungary

• Austro-Hungarian Imperial and Royal Aviation Troops

References

• Grosz, Peter M., Austro-Hungarian Army Aircraft of World War One, Flying Machine Press, Colorado, 2002.
• Gunston, Bill, World Encyclopedia of Aircraft Manufacturers, Naval Institute Press, Annapolis, 1993.
• Murphy, Justin D., Military Aircraft: Origins to 1918, ABC-Clio, Santa Barbara, 2005.
• Taylor, Michael J. H., Jane's Encyclopedia of Aviation, Studio Editions, London, 1989.