Albatros B.II

The Albatros B.II, (post-war company designation L.2) was an unarmed two-seat reconnaissance biplane designed and produced by the German aircraft manufacturer Albatros Flugzeugwerke. It was the aircraft that brought Albatros Flugzeugwerke to the world's attention.^{[citation needed]}

The design of the B.II, which included an unusually strong fuselage and an atypically flexible trailing edge, drew heavily upon the preceding Albatros B.I. Various measures were incorporated to elevate its usefulness as a reconnaissance aircraft, such as the presence of large square cutouts in the lower wing spars to increase downwards visibility from the observer's position. The pilot was seated behind the observer, rather than in front as later convention would dictate. In terms of flying performance, the B.II was inherently stabile and relatively docile, characteristics that naturally lent itself to the trainer role for which a dedicated variant, the B.IIA, would be developed. Further developments, including a floatplane and the Albatros B.III, would also be produced.

The B.II was active from the onset of the First World War, being operated by the Luftstreitkräfte during the opening year of the conflict primarily to perform aerial reconnaissance. It was displaced from frontline service due to the arrival of more capable armed reconnaissance types, and was then used as a primary trainer. The B.II proved to be an export success, being adopted by multiple countries, both inside and outside of the Central Powers. Some of these overseas operators, such as the Swedish Air Force in 1919 and the Polish Air Force, continued to operate the type even after the Armistice of 11 November 1918 that ended the conflict.

There is some dispute over the origins of this B.II; the aeronautical engineer Ernst Heinkel claimed to have designed the aircraft, however this claim is widely considered untrue by many aviation historians. It is commonly accepted that the aircraft's actual designer was Robert Thelen. Irrespective of this controversy, the design process commended during peacetime and drew extensively upon the preceding Albatros B.I. One of the most clear visual distinctions between the B.I and the B.II was a noticeably shorter wingspan of the latter.

The fuselage of the B.II, which was atypically strong for the era, was primarily composed of plywood. The primary structural members of this fuselage comprised four longerons of mixed construction, comprising ash forward of the cockpit and spruce to the aft, that tapered sharply towards the rear. The design of the fuselage was commonplace amongst the company's twin-seat aircraft. The nose of the aircraft features a rounded metal panel along with the aircraft's engine; various engines would be used to power the type, such as the Mercedes D.II, which was capable of up to 89 kW (120 hp). The majority of the engine block was uncovered. Cooling was achieved via radiators fitted to the sides of the forward fuselage alongside the cockpit.

The B.II was operated by a crew of two; as was commonplace at the time, the pilot was seated in the rear cockpit while the observer was seated in the forward position. The field of view from observer's position was partially obstructed downwards by the center-section trestle while the forward view was negatively impacted by the protruding engine block. To improve the downward field of view, large square cutouts were present in the lower wing spars; the lower wing also had a shorter span than its upper counterpart. The structure of the wing followed the company's established practices, comprising a pair of spars, the rearward of which being roughly in the middle of the wing, making the trailing edge atypically flexible and thus gave the B.II a level of inherent stability. It had ailerons with an inverse taper while the operating cables ran externally over the surface of the lower wing.

The B.II was furnished with a large triangular tail, akin to the B.I; it had an unbalanced rudder and elevator control surfaces. Both the tailplane and fin were braced via a streamlined steel strut. The structure was mainly composed of lightweight steel tubing, while the exterior covering was fabric. The undercarriage used a traditional V-shaped chassis and was also composed of steel tubing; a claw-type break was fitted to the center of the axel. The tailskid, which was made of ash, featured an elastic shock chord and was installed upon an inverted pylon structure.

Various improvements and modifications were made to the B.II following its entry to service. Many aircraft would receive strengthening, particularly around the tail unit, while the radiators were also relocated from the fuselage sides to the center of the wing's leading edge. A floatplane variant of the B.II was developed, known as the W.1 or B.II-W, as was a purpose-built trainer with increased wingspan, dual flying controls, and different engines, designated the B.IIa. Further developments of the design led to the Albatros B.III, which was produced in small numbers. Across multiple variants, large numbers of the B.II were built both on behalf of the Luftstreitkräfte and various other military air services, typically those amongst the Central Powers.