LOTTE airship

LOTTE airship

The Institute of Computational Structural Mechanics for Aeronautical Engineering of the University of Stuttgart (Stuttgart University) started the research program of "LOTTE-1" airship in 1991, and the airship was successfully test-flown in April 1993.In 1996, the University of Stuttgart started a three-year research program to carry out relevant theoretical research and technical tests using the "LOTTE" airship as a test platform. In 1996, the University of Stuttgart began a three-year research program to carry out theoretical research and technical tests with the "LOTTE" airship as a test platform. It is the world's first autonomous solar-powered airship and has been certified under the registration number D-UISD, which was developed in close cooperation with the Federal Aviation Authority in Braunschweig, Germany, as there were no guidelines for the certification of solar-powered airships at the time of its construction. The world's first autonomous solar-powered airship was built in Stuttgart (Germany) by Prof. Bernd Helmut Kröplin and his team. The LOTTE airship has been operated since 1994 by Airship Technologies GmbH, a company founded specifically for this purpose.

Historical design concepts for rigid or non-rigid airships could not produce the small airships that people wanted. Rigid airships have the disadvantage of high structural weight, whereas non-rigid airships cannot generate such high internal pressures and require less energy to stabilize the cladding. The result of this work is a new design concept, the quasi-rigid airship.

"LOTTE" was officially handed over to the Zeppelin Museum on November 27, 2014.

Development history

Model	Release Date	Payload	Features
LOTTE Airship 1	1991	unknown	Substantially completed the design and flight characteristics of the airship.
LOTTE Airship 2	1993	8kg	Reduced structural weight with new cladding and new fins.
LOTTE Airship 3	1995	12-15kg	Advanced radio control as well as energy conversion systems.

At the end of 1991, a team of students, scientists and teachers was formed, and about 20 months later the first flight of a blimp called LOTTE 1 was successful. Basic experience was gained with the design and flight characteristics of the airship.

Unfortunately, a severe thunderstorm in the summer of 1993 destroyed the airship. Over the next six weeks, the airship was rebuilt with some minor modifications, LOTTE 2 was mainly reduced in structural weight, with new cladding and new fins , and its payload was increased to 8 kg. In November 1993, it participated in the World Solar Challenge in Australia and flew about 330 kilometers in four days. On the fourth day of that challenge, the radio control system interfered with the ILS locator at a nearby military airfield, and the airship lost ground control, disabled its internal safety systems, and finally landed in a tree. The high tail winds at the time (10 - 15 knots) resulted in severe damage to the airship, which could not be repaired in the Australian bush.

The structural components of the LOTTE 3 airship are almost identical to those of the previous two generations, but with new electronic systems, advanced radio control and energy conversion systems. The solar generator and batteries are now modular in design, which allows the maximum payload to be increased to 12-15 kilograms, depending on flight requirements. LOTTE 3 completed certification testing in 1995.