In the late 20's early 30s the German company Albatros Flugzeugwerke GmbH, Berlin-Johannisthal , belonged to the number of firms that were commissioned by the so-called "Büro Nicolaus" Ministry of Railways,  to  develop in secret military aircraft. Under the designation of "high-speed mail plane" they developed fighters and scouts..
One of the most interesting and little-known aircraft,  was Albatros L 81 Electra . This concerned both the design of the aircraft, as well as what were  used in its construction materials.
Albatros L 81 Electra was the first aircraft, which was used in the manufacture a metal  called "electron" ("Elektron"). it was also used alloying material AZM.
The company Albatros use this material for the manufacture of propellers and engine hood, top and side walls of the fuselage, the wing skin, chassis fairing and radiator, as well as for the manufacture of chairs.
The introduction of new materials and new best methods of manufacturing the structural elements of the aircraft for  were not new. For example, the production of steel welded structures was one of the most developed in the company and has already fulfilled the areas relating to the application of new technologies in aviation. The company was actively engaged in the introduction of new aircraft with the best steels.
Few people know that the company Albatros pioneered in the production of specially designed steel grade ErMo. Use of this steel was of particular importance, and as a result all the German aircraft industry and the entire German industry gradually began to use steel of this brand. ErMo gradually replaced the previously widely used in industrial grade steel ErNi.
Development of new material brought electron company Albatros at the forefront in this area. When the development of a new project known as L 81 Electra, Albatros company has already received extensive practical experience in numerous previously conducted research. Electra aircraft was the test platform for new technologies.

From the available literature at our disposal L 81 (on-board identification mark D-2198, serial number 360) was built in 1932. . In fact, numerous reports on the progress of the various tests related to the size of the wing, and strength tests dated it to 1932. While the doctor-engineer J. Müller led the company owned by Focke-Wulf research center was  engaged in the development and introduction of new materials and in 1930  In the magazine "Der Condor" was printed reports by Müller, which mentions the importance of this work in terms of the introduction of light alloys in aircraft construction.
L 81 Electra 1932 belonged to the German community "Reichsverband der Deutschen Luftfahrtindustrie" and was at Berlin-Staaken test center .  Electra L 81  was tested there and after 1936..
Brief description
The prototype bomber L 81 Electra, was developed in 1930 by Albatros Flugzeugwerke GmbH, Berlin-Johannisthal
The design of the prototype, it was decided to apply a number of new materials (primarily electron AZM) and new assembly methods.
The aircraft wings had a diagonal arrangement of the elements of the outer skin. Ailerons are located only on the lower wing.
The inner part of the wing between the ribs and the front part of the plane were  covered with thin sheets of metal, the upper and lower surfaces of the wings are covered with fabric
Struts N-shaped connecting the lower and upper wings. The front part of the upper wing center section had thin metal sheets.
Fuselage pear shape. At the rear of the cross sectional form close to rectangular. In the upper part of the fuselage angles are semicircular. Metal fuselage.
Good clearance between  the bottom of the fuselage and the ground. The observer is being protected from air flow during the occupation of their positions "standing" and "sitting".
Signal pistols and cartridges for them are also located in the fuselage and protected. The fuselage is narrowed in the upper portion, which provides a good overview for the pilot, and is similar in shape as  the  L 75 "Ass".
The main landing gear with oil shock absorbers and rubber tires filled with compressed air. Chassis with separate main landing location developed by Albatros.
Tail skid, also developed by Albatros, well designed to easy   manoevering of the aircraft on the surface, thereby eliminating the need for assistance of ground staff in strong crosswind. Tail skid spring-loaded by rubber elements.
Empennage. Horizontal tail consisting of a stabilizer and elevators, located high and is made in the form of a trapezium with  swept leading edge. At the lower edge of the fuselage are supporting  I-shaped struts.
Vertical tail consists of a rudder. Elevators and ailerons are  weight balanced.
The power plant of the aircraft is an inline six-cylinder water-cooled engine BMW Va capacity 320/360/395 hp  The frame of the power plant was covered with steel and easily removable lining. The motor was attached to the fuselage at four points. Behind the engine was installed a steel fire wall, behind which the fuselage was located under a covering of the fuel tank. Various pipelines and other elements with open hatches were clearly visible and accessible for maintenance and repair.
Type Two seat experimental aircraft 
Engine 1 BMW Va
Dimensions Length 10,0 m , height  ,  span 12,5 m , wing area   ,
Weights Empty 1200 kg, loaded  1920 kg, max. take off weight  
Performance Max.. speed  , cruising speed  , range , endurance  , service ceiling   , climb
Type Werk.Nr Registration History
A 10164 , 360 ? D-2198, D-IDUK Built 1931. First aircraft using the Elektron metal. Used by the DVL at Berlin-Staaken, later at Rechlin