Akaflieg Darmstadt D-7 Margarete

Last updated
D-7 Margarete
Akaflieg Darmstadt D-7 Margarete.jpg
RoleTwo seat glider
National origin Germany
Manufacturer Akaflieg Darmstadt
DesignerFritz Hoppe, R. Kercher and E.Schatzki [1]
First flight1923
Number built1

The Akaflieg Darmstadt D-7 Margarete, often shortened to Darmstadt D-7 Margarete, was one of the earliest two seat monoplane gliders, designed and built by German university students in 1923.

Contents

Development

The Akademische Fliegergruppe of the Technical University of Darmstadt was first formed in 1921. It was, and is, a group of aeronautical students who design and construct aircraft as part of their studies and with the help and encouragement of their University. The 1923 D-7 monoplane was their first two-seat design and one of the first of its kind, though the Fokker FG-2 two seat biplane glider flew the previous year; the D-7 was named after the wife of an Akaflieg Darmstadt student killed at the first Rhön (Wasserkuppe) glider meeting in 1920. [2]

The Margarete was a wood-framed aircraft with a high, braced, two spar wing with ply covering from the front spar to the leading edge and fabric covered aft. The wing had a thick and cambered profile inboard of the tips, which had a thinner and more symmetric profile. Initially the wing plan was rectangular, with triangular ailerons mounted on straight hinges which were attached to the front spar at the tips, reaching the trailing edge inboard. Later, the aileron area was reduced, partly by cropping them inboard and also by tapering their trailing edges and rounding their tips. Each wing was braced from the lower fuselage with an asymmetric, V-form, streamlined strut to the two spars at about one-third span. [2]

The fuselage was plywood covered with a flat top, deep, slightly curved sides and a V-shaped bottom. The nose was blunt and the open, unscreened cockpit used for solo flying was well forward of the wing leading edge. The separate second cockpit was under the wing, close to the centre of gravity so that its occupation did not seriously affect the trim. The wing centre section was supported above this cockpit on an extension of the upper rear fuselage, which dropped away aft to become slender at the tail. There was a short undercarriage skid attached directly to the fuselage underside, aided by a small tailskid. A narrow, triangular, ply covered fin carried a fabric covered, trapezoidal rudder which extended to the bottom of the fuselage. The fabric covered tailplane was mounted on the top of the fuselage; in plan, tailplane and elevators were straight edged, only slightly tapered and with angled tips. A small elevator cut-out allowed rudder movement. [2]

Operational history

The D-7 Margarete first flew in 1923 [2] and took part in both the 1923 [3] and 1924 [4] Rhön events, setting an unofficial record at the latter with a passenger-carrying flight of 21 minutes. [5] It was later used for passenger flights, though not for basic training, until it was written off in 1927 when an aileron cable broke during landing. [2]

Specifications

Data from Sailplanes 1920-1945 [2]

General characteristics

Performance

Related Research Articles

Akaflieg Darmstadt is one of approximately twenty aviation groups attached to German universities. Akaflieg is an abbreviation for Akademische Fliegergruppe, an academic group of students and faculty from a German University.

<span class="mw-page-title-main">Hannover H 1 Vampyr</span> German single-seat glider, 1921

The Hannover H.1 Vampyr was a German glider designed by Georg Madelung for the 1921 Rhön gliding competition, which was held at the Wasserkuppe from 8 August to 25 August 1921. The Vampyr is believed to be the first heavier than air aircraft to use stressed skin. Several historical societies have argued that the aircraft is the precursor of all modern sailplanes.

The Akaflieg Darmstadt D-6 Geheimrat, often shortened to Darmstadt D-6 Geheimrat, was an early competition glider with a single seat and high cantilever wing, designed and built by German University students in 1922.

<span class="mw-page-title-main">Akaflieg Darmstadt D-9 Konsul</span> German single-seat glider, 1923

The Akaflieg Darmstadt D-9 Konsul, often shortened to Darmstadt D-9 Konsul, was a high performance, single seat, cantilever monoplane sailplane, designed and built by a German University student group in 1923 for hill soaring.

The Akaflieg Darmstadt D-17 Darmstadt, also called the Darmstadt D-17 and Darmstadt I, was a high performance, single seat, cantilever monoplane sailplane, designed and built by a German University student design group in 1927. It was followed in 1928 by the Akaflieg Darmstadt D-19 Darmstadt 2, a similar aircraft with a new profile, longer span wing.

The Akaflieg Darmstadt D-28 Windspiel was a single-seat, high-performance sailplane designed in Germany in the early 1930s. Intended to exploit a growing understanding of thermal soaring, it was small and manoeuvrable, with a 12 m span; silk-covered for lightness, it weighed less (empty) than its pilots. It held the world straight-line distance record for a time in 1934.

The Akaflieg Darmstadt D-30 Cirrus was an aerodynamically advanced single seat sailplane with a very high aspect ratio wing and a pod and boom fuselage. Built in Germany just before World War II, it was intended as a record breaker and duly set a new world out-and-return distance record in 1938.

The Akaflieg Darmstadt D-34 sailplanes were a series of experimental single seat sailplanes, designed at the University of Darmstadt in the 1950s and early 1960s to explore the structural and aerodynamic advantages of the then emerging plastics and composite materials.

The Akaflieg Darmstadt D-40 is an experimental variable geometry single seat sailplane, fitted with almost full span, camber changing flaps for optimum aerodynamics in weak thermals and integrated into the wing so as to minimise flap tip drag. One flew successfully but the D-40, like other variable geometry sailplanes, was not commercialised.

<span class="mw-page-title-main">DFS Rhönsperber</span> German single seat competition glider, 1937

The DFS Rhönsperber, otherwise known as the Schweyer Rhönsperber or Jacobs Rhönsperber was a single seat competition glider designed in Germany by Hans Jacobs and first flown in 1935. For several years it was regarded as the best German sailplane and about one hundred were built.

<span class="mw-page-title-main">Schleicher Rhönadler</span> German single-seat glider, 1932

The Schleicher Rhönadler, DFS Rhönadler or Jacobs Rhönadler is a high performance, single seat competition sailplane built in Germany in the 1930s. More than 65 were built.

The Teichfuss Gabbiano was an Italian, one-off, single seat, high performance glider, designed by Luigi Teichfuss and flown in 1928.

<span class="mw-page-title-main">RRG Fafnir</span> German single-seat glider, 1930

The RRG Fafnir, named after the legendary dragon, was a single seat German high performance glider designed by Alexander Lippisch. It won the Rhön competition in 1931 and made several outstanding flights as well as setting a fashion for gull wings.

The RRG Professor was a very early soaring glider and the first to use a variometer for finding thermals. It was designed by Alexander Lippisch in Germany, first flying in 1928. The Professor was widely built by both flying clubs and factories.

The Musger Mg 9 was a tandem two seat glider built in Austria in the mid-1930s. It broke both world and national records.

<i>Lore</i> (glider) German single-seat glider, 1929

Lore and a copy, Musterle, were high performance sailplanes designed at Darmstadt by Paul Laubenthal. Lore was flown successfully by the well known glider pilot Wolf Hirth at the 1929 Rhön (Wasserkuppe) glider competition. Musterle was used by Hirth used to demonstrate the possibilities of "blue sky" thermalling for the first time.

The Laubenthal Württemberg, sometimes known after its constructors as the Akaflieg Darmstadt Württemberg, was a single seat glider designed by Paul Laubenthal and built at the University of Darmstadt for Wolf Hirth, who won four prizes in it at an international competition in France in 1928. A second machine was built in 1929 by the Klemm Leichtflugzeugbau GmbH.

<i>Der Dessauer</i> German single-seat glider, 1923

The Der Dessauer, later Der alte Dessauer, was a German single-seat glider built in the early 1920s. It took part in all the Rhön gliding contests on the Wasserkuppe between 1923 and 1928, flew in the Alps, and made a long-duration flight along the German sea shore.

The F.V.D. Doris or Dresden Doris, later known as the Akaflieg Dresden D-B2 Doris, was a monoplane glider built in Germany in 1922. It was unusual in having wings which could independently adjust their angles of attack, a feature intended to increase the energy acquired from gusts of wind.

<span class="mw-page-title-main">Hannover Greif</span> German single-seat glider, 1922

The Akaflieg Hannover H.2 Greif was a 1922 development of the successful Vampyr glider. Though it flew in three successive Rhön (Wasserkuppe) contests, it failed to match the achievements of its predecessor.

References

  1. "Darmstadt D-19" . Retrieved 18 January 2012.
  2. 1 2 3 4 5 6 Simons, Martin (2006). Sailplanes 1920-1945 (2nd revised ed.). Königswinter: EQIP Werbung & Verlag GmbH. pp. 21, 26–7. ISBN   3-9806773-4-6.
  3. "Some Rhön gliders". Flight . Vol. XVI, no. 10. 8 March 1924. p. 131.
  4. "The Rhön machines, 1924". Flight . Vol. XVI, no. 35. 28 August 1924. pp. 542–3.
  5. "Light Plane and Glider Notes". Flight . Vol. XVI, no. 36. 4 September 1924. p. 554.