Summary of an aircraft accident in Reinheim: A comprehensive accident report
On 25 September 2021, an accident occurred between a manned aircraft, a Robin DR 400/180 R, and an unmanned model aircraft at the Reinheim gliding site. This accident resulted in considerable material damage, but fortunately no injuries. The following is a detailed summary of the accident report from the Federal Bureau of Aircraft Accident Investigation (BFU).
Course of the accident
The accident occurred when the manned aircraft took off from runway 19 of the Reinheim gliding site at 3.25 p.m. with a glider in tow. At around the same time, a model aeroplane took off from a nearby model flying site. The two aircraft collided about a minute later at an altitude of approximately 100 metres above ground level (AGL).
Flight path and collision
The DR 400/180 R, towed by a DG-1000S, turned left after take-off at an altitude of around 40 metres in order to avoid flying over a nearby village. The tow train reached an altitude of approximately 200 metres above sea level (AMSL) 20 seconds after take-off. At this moment, the glider pilot noticed a model aircraft in the 11 o'clock position and warned the pilot of the DR 400/180 R by radio.
The pilot of the towing aircraft spotted the model aircraft in its 1 o'clock position and saw it flying below him until it disappeared from his field of vision. A few seconds later, the model aircraft collided with the left tailplane of the DR 400/180 R from below. The collision occurred at the south-western boundary of the model flying site at an altitude of approx. 300 metres AMSL (100 metres AGL).
Causes and circumstances of the accident
Pilot and model aircraft
The 56-year-old pilot of the DR 400/180 R held a private pilot's licence (PPL(A)) and a towing licence for gliders. His total flying experience comprised 346 hours on single-engine piston aeroplanes and 871 towing flights.
The 55-year-old remote pilot of the model aircraft had been an active model pilot for 42 years. The model aircraft was a home-built model with a GRP fuselage and a wing covered with balsa wood, powered by a two-stroke engine with a displacement of 10 cc.
Weather conditions
At the time of the accident, visual flight conditions were good with light winds, an air temperature of 25°C and clear visibility.
Authorisations and operating regulations
The Reinheim gliding site is located approx. 800 metres north-east of the village of Reinheim and has a 770 metre long runway. The model flying site is located approx. 1,600 metres west of the village of Nieder-Klingen. Both sites had valid operating licences, but these did not provide for any special coordination between the two airfields.
Test results
The investigation revealed that the collision was due to the following factors:
- The remote pilot of the model aircraft was focussed on controlling his model and was unable to notice the approaching tow train.
- The noise of the model aircraft possibly masked the sound of the approaching tow train.
- The tow train approached the flight area of the model flying site at a low altitude.
- The pilot of the DR 400/180 R was unaware of the existence of the model flying site.
- The tow train flew into the flight area of the model flying site without taking evasive action in good time.
Safety measures and recommendations
In November 2023, an operational agreement was reached between the operators of the gliding site and the model flying site in order to improve users' situational awareness and avoid future collisions.
Suggestions for preventing future accidents:
- Better communication and coordination: Clear agreements should be made between the operators of the various airfields in order to coordinate flight routes and altitudes.
- Technological support: The use of warning devices, such as those used in Switzerland, could help to warn pilots and remote pilots of potential collisions in good time.
- Advanced training: Both pilots and remote pilots should be regularly trained in airspace observation and recognising approaches.
Conclusion
The accident report shows the need for better coordination and communication between manned and unmanned aircraft. Targeted measures and technologies can prevent such accidents in the future in order to ensure safety in the airspace.
Source references:
Federal Bureau of Aircraft Accident Investigation