The DFS Sperber Senior ( en, Hawk Senior) was a competition

sailplane A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailpla ...

designed and built in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

in 1936. During 1937 the sole example visited the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

and scored highest in the US National Soaring Competition.

Design and development

Although nominally a development of his earlier DFS Rhönsperber,

Hans Jacobs Hans Jacobs (30 April 1907 in Hamburg - 24 October 1994) was a German sailplane designer and pioneer. He had been taught sailplane design by Alexander Lippisch, designer of many gliders during the 1920s and the 1930s. As the head of the ''Deut ...

' Sperber Senior was a completely new design intended to improve on the performance of its predecessor and to accommodate larger pilots. It was a

shoulder wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

aircraft with a double straight tapered

gull wing The gull wing is an aircraft wing configuration, known also as ''Pulaski wings'', with a prominent bend in the wing inner section towards the wing root. Its name is derived from the seabirds which it resembles. Numerous aircraft have incorpora ...

, built around two spars and fabric covered apart from the

leading edge The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...

from the front spar forward and the wing roots, which were plywood skinned. The wing roots were carefully faired into the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraf ...

. The inner panels, filling about one third of the span had only slight taper, the sweep entirely on the

trailing edge The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 199 ...

, and about 10° of dihedral. Outboard the taper was much stronger, with a taper ratio of 0.45. Here the leading edge was slightly swept but there was no dihedral.

Ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

occupied the whole of the outer panels' trailing edges. The Senior had a completely ply covered fuselage with a narrow ovoid cross section which was deep in the cockpit area but tapered progressively to the tail. The cockpit was just ahead of the wing, covered by a multipart glazing which, attached to a small area of the upper forward fuselage, hinged to the right for access. The rear of the

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...

was above the fuselage line and a long, ply covered fairing reaching well behind the wing blended it in. A tapered, round tipped and largely fabric covered horizontal tail was mounted on top of the fuselage, far enough forward to place the trailing edges of its

elevators An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They are ...

at the

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...

hinge line. The latter was mounted on a narrow ply covered

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...

, carefully faired into the fuselage and extending below it to form a tail bumper. The mostly fabric covered rudder was full, curved and slightly pointed, likewise extending below the fuselage. A short skid from just behind the nose to beyond mid-chord completed the

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

Operational history

The Sperber Senior first flew in 1936 and took part in the Rhön German National championships of that year but its pilot, Ludwig Hofmann retired for personal reasons midway through. In 1937 Peter Riedel took it to the US to participate in the 8th American National Competitions at Elmira. He finished with the highest score but, not being a US citizen was denied the title of champion. Whilst in the US he made a seven-hour flight over central New York. After he returned to Germany the Sperber Senior was retired.

Specifications

References

{{DFS aircraft 1930s German sailplanes DFS aircraft Glider aircraft Shoulder-wing aircraft Aircraft first flown in 1936 Gull-wing aircraft