September 30, 2019 | In-flight avoidance

Sensors replace pilots

  • Flight tests with DLR research aircraft DO 228 D-CODE and Falcon 20E.
  • Successful test of sensors to avoid collisions between unmanned aerial vehicles.
  • Focal points: Aeronautics, unmanned flight, digitalisation.

The companies Diehl and HENSOLDT carried out flight tests in July and August 2019 together with the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) on a new sensor system to increase air safety. The idea is to prevent collisions between aircraft. In future, the sensors tested for detecting and avoiding collisions (‘Sense and Avoid’) could enable the approval and operation of unmanned aerial systems (‘drones’) in German airspace for the first time.

In a three-week-long flight test campaign at Braunschweig research airport, it was demonstrated that modern sensors can replace the pilot’s eye in flight tests carried out for more than 30 hours. For this purpose, the DLR research aircraft Dornier DO 228 was equipped with a ‘dual-mode sensor suite’ manufactured by Diehl and HENSOLDT, consisting of radar and electro-optical sensors. The optical signals of special cameras were combined with radar signals. In addition to DLR’s DO 228, one more research aircraft was used for the tests. This aircraft made extensive manoeuvres from different directions and heights and had to be detected by the sensor system on the DO 228. It was found in the flight tests that the sensor suite detected the other aircraft, even at long distances, in a reliable, accurate manner, tracked it precisely, and could warn its own aircraft of a potential collision course sufficiently early.

The electro-optical module from Diehl consists of a series of high-resolution cameras that scan the area in front of as well as the to the side of the aircraft. It was demonstrated that this system can replace the pilot’s view and significantly increases the accuracy of the overall system. The module is lightweight and compact and can be flexibly modified to meet the requirements of different aircraft.

The ‘Detect-and-Avoid’ radar made by HENSOLDT employs electronic beam steering technology (Active Electronically Scanned Array, AESA). This allows several detection tasks to be performed simultaneously and objects to be detected extremely quickly. Thanks to radar technology, the flight direction of objects in one’s own flight path can be measured precisely so as to be warned about potential collisions in a timely manner. With its unique detection properties, the multi-functional radar is suitable for military as well as civilian drones – for example, for cargo delivery. In addition, the sensor also performs all the functions of a weather radar. The combination of these two technologies (dual-mode sensor system) is suitable for unmanned aerial vehicles of different sizes and also has excellent detection properties.

The universal DLR research aircraft is regularly equipped and used as a flying platform for a wide variety of research tasks. For the research into unmanned aerial systems, it serves as a ‘National Sense and Avoid Demonstrator’. Using a new type of digital autopilot, the aircraft can be automatically controlled from a ground station. It can safely simulate an unmanned aerial system, because two safety pilots are always on board the aircraft. The flight tests were conducted as part of the ‘Project Sense and Avoid - national’ (ProSA-n) project, which has been commissioned by the Federal Office of Bundeswehr Equipment, Information Technology and In-Service Support (Bundesamt für Ausrüstung, Informationstechnik und Nutzung der Bundeswehr; BAAINBw).

About DLR

The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is the national aeronautics and space research centre of the Federal Republic of Germany. Its extensive research and development work in aeronautics, space, energy, transport, security and digitalisation is integrated into national and international cooperative ventures. DLR is also responsible for the planning and implementation of Germany's space activities on behalf of the federal government. DLR is also the umbrella organisation for one of Germany's largest project management agencies.

DLR has approximately 8600 employees at 27 locations in Germany. It also has international offices in Brussels, Paris, Tokyo and Washington D.C.

About Diehl Defence

Diehl Defence combines the Diehl Group’s business activities in the fields of security and defence. As a parent company, Diehl Defence manages numerous subsidiaries, programmes and affiliated companies. With 2509 employees*, the corporate division generates annual sales of € 464 million Euro. (Key Business Data 2018).


HENSOLDT is a pioneer of technology and innovation in the field of defense and security electronics. The company, based in Taufkirchen near Munich, is one of the market leaders in the field of civil and military sensor solutions. It develops new products to combat various threats on the basis of innovative approaches to data management, robotics and cyber security. HENSOLDT has approximately 4500 employees and an annual turnover of more than one billion euro.

About the BAAINBw

The Federal Office of Bundeswehr Equipment, Information Technology and In-Service Support (Bundesamt für Ausrüstung, Informationstechnik und Nutzung der Bundeswehr BAAINBw) was established on 1 October 2012 as part of the realignment of the German armed forces. Structurally, the Federal Office, including its subordinate departments, has around 11,000 employees across the country of which more than 5000 people are based at the location in Koblenz. The Federal Office is assisted by a business division which is technologically and scientifically broad-based having six military technology and two military science departments. The Naval Arsenal in Wilhelmshaven provides ships and boats for the German Navy as an additional department. A liaison department in Reston / USA represents the military technology and armament interests vis-a-vis the American and Canadian bodies as well as vis-a-vis the local industry.

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Falk Dambowsky

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