| Type | Werk.Nr | Registration | History |
| The Meiningen glider, with a wingspan of 22 m, was the largest glider built up to that time. Designed by Hermann BENZ, it was built by the Aeronautical Association of Meiningen (small town 50 km east of Wasserkuppe). He took part in the Rhön competition in 1930 (competition number 24). It appears it flew twice then was damaged in a landing accident(?). |
| Type | Single seat hogh performance glider |
| Dimensions | Length 5 m , height , span 22 m , wing area 21 m2 , aspect ratio 23 |
| Weights | Empty , loaded , max. take off weight |
| Performance | Max.. speed , gliding ratio 33, min sink 0,38 m/sec. at 47 km/h |
Glider high-performance aircraft "Meiningen".
By Ing. Benz, Meiningen.
In the following, the work carried out quietly on the high-performance glider aircraft "Meiningen" of the Meiningen Aviation Association will be shown. With the
publication of the individual construction details, we hope to be able to give the gliding clubs useful suggestions for the constructive design of gliders
.
As the designer of the "Meiningen" I would like to remark from the outset that the "Meiningen" is to be regarded as an experimental construction of various design problems of components carried out on this machine, which are novel for glider
construction.
In this year's Rhön gliding competition, practice will show how far the use of this constructive gliding high-performance machine "Meiningen" can be felt in the future.
Wing capacity 21 m2, Elevator capacity 3.4 m2, Rudder capacity 1.6 m2, Aileron capacity 1.68 m2, Empty weight 160 kg, Flying weight 230 kg, Wing loading 10.8
kg/m2, Airspeed 12-14 ml sec., Glide ratio 33 : 1, Sink rate 0.38 ml sec.
The formation of the individual components can be made possible. Since only the internal structure differs from the previous design of the parts, while the external shape of the
known high-performance type has been retained for the time being, the following tests are not limited to a particular type.
Rather, in my opinion, the tailless and especially the wing-only aircraft that are planned for the future can also be built with such or similar
interior designs.
The future will have to prove whether the question of economic efficiency, i.e. the construction work expended, will be in a favourable relationship to the performance success achieved.
In my opinion, this question also plays a more subordinate role in the case of high-performance gliders bred only for performance. Rather, these
machines are to be used to effectively fertilize the school sailors, whose design does not yet meet the diverse requirements of practice
.
The main dimensions of the "Meiningen" are shown in Fig. 1. The aerodynamic properties result from the following principles:
A combination of the Göttingen profiles 386/390/420 was chosen as the wing profile. Towards the wing tips, the 420 shape predominates. The angle of adjustment increases
outwards from + 4.5° at the base of the wing to 1° at the end of the wing in such a ratio that, taking into account the outline of the wings, a purely elliptical
lift distribution takes place. At the same time, with this combination of profiles, the movement of means of pressure was kept to a minimum and a sufficient profile thickness was achieved at the base of the wing without creating too much forehead resistance.
The Qöttinger profile No. 410 with an average rudder depth of 2/31 was used as the elevator and rudder profile.The
inner structure of the wings (see Figs. 2, 3 and 4) consists of four, mutually supporting, sloping, dissolved lattice spars in wooden construction, which are 30% of the
lattice spars due to the absorption of torsional forces.rnis. The individual spars consist of 2 parallel lower and 2 upper chord strips, the distance
between which is ensured by compression rods. The spar diagonals made of Cawit plywood,
of decreasing width towards the outside, are connected to the knotted plates glued between the dissolved spar belts by ample glue surface. The hinge belts are stiffened on the outside by corner blocks along their half bending length between the spars, and connected on the inside
by semicircular curved shears pointing alternately to the left and right diagonal fibres. This makes the internal construction, which supports three-quarters of the wing depth
, extremely torsionally rigid. A thin outer skin on the wing snout significantly supports torsional strength.
The dimensions of the spar chords, push rods, diagonals and knotted plates have
been determined on the basis of the buoyancy loads applied by the spars; for this it was necessary to place the nodes of the diagonals and compression bars on the middle spars. This measure also offers the advantage that the compression rods could be connected
halfway along the length to the spar diagonals by interconnecting small plywood surfaces, whereby the free buckling length of the rods is reduced to
half. In the end parts of the wings, the semicircular curved spar shearer surfaces are missing, while the corner blocks are installed halfway along the bend length of the spar straps.
Here, the outer skin offers enough resistance to , compared to the normal 2-spar design with internal diagonal struts. Shifting the spar straps each other and thus against torsion. With the selected static structure of the spars, tension or pressure occurs in the
spar chords, tension always in the diagonals and pressure in the vertical rods. Double diagonals were installed to control the wing mass forces during
landing. A gradation in the dimensioning of the diagonals loaded during flight and landing corresponding to these forces was
taken into account.
As an example of the weight savings achieved through the complete dissolution of the load-bearing internal parts, the dimensions of the individual belt strips, compression rods and diagonals are
listed. Central wing: belt strips 30X10 mm, compression bars 10X8 mm, diagonals 38X1.2 mm.Wing
outside: belt strips 8X5 mm, compression bars 4X4 mm, diagonals 6X1.2 mm. The light aileron spars mainly engage the spars and are connected to the spars at 3 points along their length. Since these rowing spars are at an acute angle to the direction of the spars, the spars end at the points of use of the spars with the rudder spars.
The three-part surface is connected by left- and right-hand threaded bolts and nuts in the style of a turnbuckle. The 16 individual belt strips of the 4 spars
are combined at the connection points in 5 end blocks, which carry the fittings.
The connection of the wing center section to the fuselage is also done by means of a number of turnbuckles. As a wing carrier, a carrier plate is installed between the
main frames (see Fig. 5).
The outer shape of the fuselage (thickness ratio of 1 : 6.2) is ensured by an Arlzahl hollow ring frames in box design, which are supported by twelve longitudinal strips are connected in a T-cross-section
. This creates many small fields that break down the outer skin into smaller stress fields than was previously the case. Due to the
local support of the outer skin against dents or bulges, its thickness can be reduced to 2 to 1.2 mm, depending on the position on the fuselage, without
reducing the strength. In the front lower part of the fuselage, a keel plate of 3 m length and double T-cross-section is installed as an innovation, which
absorbs all forces during take-off and landing (see Fig. 5). The suspension runners engage it by means of a new type of ram suspension (see Figs. 6 and 8). The starting hook is located on the front part, while
a hook for the automatic release device is attached to the end. Furthermore, this beam absorbs the pilot's weight and the forces of the wing by
transmitting specially formed main frames (cf. Figs. 9 and 10)- The keel plate also carries the steering column with control stick and the pedals of the
rudder. The keel plate thus contributes to extensive relief of the outer skin.
While the horizontal sections of the fuselage are streamlined curves, the vertical sections viewed from front to back show: narrow vertical ellipses which, gradually becoming
wider, merge into a circular shape and become narrow flat edge ellipses towards the rear. The front end is formed by an
aluminum hood made of one piece. A sufficiently high streamlined grinding head at the rear lower end of the fuselage protects the elevator from possible damage during take-off and
landing.
By Ing. Benz, Meiningen.
In the following, the work carried out quietly on the high-performance glider aircraft "Meiningen" of the Meiningen Aviation Association will be shown. With the
publication of the individual construction details, we hope to be able to give the gliding clubs useful suggestions for the constructive design of gliders
.
As the designer of the "Meiningen" I would like to remark from the outset that the "Meiningen" is to be regarded as an experimental construction of various design problems of components carried out on this machine, which are novel for glider
construction.
In this year's Rhön gliding competition, practice will show how far the use of this constructive gliding high-performance machine "Meiningen" can be felt in the future.
Wing capacity 21 m2, Elevator capacity 3.4 m2, Rudder capacity 1.6 m2, Aileron capacity 1.68 m2, Empty weight 160 kg, Flying weight 230 kg, Wing loading 10.8
kg/m2, Airspeed 12-14 ml sec., Glide ratio 33 : 1, Sink rate 0.38 ml sec.
The formation of the individual components can be made possible. Since only the internal structure differs from the previous design of the parts, while the external shape of the
known high-performance type has been retained for the time being, the following tests are not limited to a particular type.
Rather, in my opinion, the tailless and especially the wing-only aircraft that are planned for the future can also be built with such or similar
interior designs.
The future will have to prove whether the question of economic efficiency, i.e. the construction work expended, will be in a favourable relationship to the performance success achieved.
In my opinion, this question also plays a more subordinate role in the case of high-performance gliders bred only for performance. Rather, these
machines are to be used to effectively fertilize the school sailors, whose design does not yet meet the diverse requirements of practice
.
The main dimensions of the "Meiningen" are shown in Fig. 1. The aerodynamic properties result from the following principles:
A combination of the Göttingen profiles 386/390/420 was chosen as the wing profile. Towards the wing tips, the 420 shape predominates. The angle of adjustment increases
outwards from + 4.5° at the base of the wing to 1° at the end of the wing in such a ratio that, taking into account the outline of the wings, a purely elliptical
lift distribution takes place. At the same time, with this combination of profiles, the movement of means of pressure was kept to a minimum and a sufficient profile thickness was achieved at the base of the wing without creating too much forehead resistance.
The Qöttinger profile No. 410 with an average rudder depth of 2/31 was used as the elevator and rudder profile.The
inner structure of the wings (see Figs. 2, 3 and 4) consists of four, mutually supporting, sloping, dissolved lattice spars in wooden construction, which are 30% of the
lattice spars due to the absorption of torsional forces.rnis. The individual spars consist of 2 parallel lower and 2 upper chord strips, the distance
between which is ensured by compression rods. The spar diagonals made of Cawit plywood,
of decreasing width towards the outside, are connected to the knotted plates glued between the dissolved spar belts by ample glue surface. The hinge belts are stiffened on the outside by corner blocks along their half bending length between the spars, and connected on the inside
by semicircular curved shears pointing alternately to the left and right diagonal fibres. This makes the internal construction, which supports three-quarters of the wing depth
, extremely torsionally rigid. A thin outer skin on the wing snout significantly supports torsional strength.
The dimensions of the spar chords, push rods, diagonals and knotted plates have
been determined on the basis of the buoyancy loads applied by the spars; for this it was necessary to place the nodes of the diagonals and compression bars on the middle spars. This measure also offers the advantage that the compression rods could be connected
halfway along the length to the spar diagonals by interconnecting small plywood surfaces, whereby the free buckling length of the rods is reduced to
half. In the end parts of the wings, the semicircular curved spar shearer surfaces are missing, while the corner blocks are installed halfway along the bend length of the spar straps.
Here, the outer skin offers enough resistance to , compared to the normal 2-spar design with internal diagonal struts. Shifting the spar straps each other and thus against torsion. With the selected static structure of the spars, tension or pressure occurs in the
spar chords, tension always in the diagonals and pressure in the vertical rods. Double diagonals were installed to control the wing mass forces during
landing. A gradation in the dimensioning of the diagonals loaded during flight and landing corresponding to these forces was
taken into account.
As an example of the weight savings achieved through the complete dissolution of the load-bearing internal parts, the dimensions of the individual belt strips, compression rods and diagonals are
listed. Central wing: belt strips 30X10 mm, compression bars 10X8 mm, diagonals 38X1.2 mm.Wing
outside: belt strips 8X5 mm, compression bars 4X4 mm, diagonals 6X1.2 mm. The light aileron spars mainly engage the spars and are connected to the spars at 3 points along their length. Since these rowing spars are at an acute angle to the direction of the spars, the spars end at the points of use of the spars with the rudder spars.
The three-part surface is connected by left- and right-hand threaded bolts and nuts in the style of a turnbuckle. The 16 individual belt strips of the 4 spars
are combined at the connection points in 5 end blocks, which carry the fittings.
The connection of the wing center section to the fuselage is also done by means of a number of turnbuckles. As a wing carrier, a carrier plate is installed between the
main frames (see Fig. 5).
The outer shape of the fuselage (thickness ratio of 1 : 6.2) is ensured by an Arlzahl hollow ring frames in box design, which are supported by twelve longitudinal strips are connected in a T-cross-section
. This creates many small fields that break down the outer skin into smaller stress fields than was previously the case. Due to the
local support of the outer skin against dents or bulges, its thickness can be reduced to 2 to 1.2 mm, depending on the position on the fuselage, without
reducing the strength. In the front lower part of the fuselage, a keel plate of 3 m length and double T-cross-section is installed as an innovation, which
absorbs all forces during take-off and landing (see Fig. 5). The suspension runners engage it by means of a new type of ram suspension (see Figs. 6 and 8). The starting hook is located on the front part, while
a hook for the automatic release device is attached to the end. Furthermore, this beam absorbs the pilot's weight and the forces of the wing by
transmitting specially formed main frames (cf. Figs. 9 and 10)- The keel plate also carries the steering column with control stick and the pedals of the
rudder. The keel plate thus contributes to extensive relief of the outer skin.
While the horizontal sections of the fuselage are streamlined curves, the vertical sections viewed from front to back show: narrow vertical ellipses which, gradually becoming
wider, merge into a circular shape and become narrow flat edge ellipses towards the rear. The front end is formed by an
aluminum hood made of one piece. A sufficiently high streamlined grinding head at the rear lower end of the fuselage protects the elevator from possible damage during take-off and
landing.
