The Chinese company DJI, specialized in the manufacture of unmanned aerial vehicles for civilians, demanded to eliminate publications and videos about the study in which the Phantom 2 drone crashes into an airplane wing at a speed of 383 km / h.
The request is contained in a letter to researcher Kevin Purmon, of the University of Dayton in Ohio, who led the experiment in question. The Chinese company argues that the conditions of the experiment are unlikely, and states in the letter its disagreement with the little detail that the research provides on its own methodology.
The results of the study were published in September of this year. In the course of the experiment, the researchers launched the DJI Phantom 2 drone against a wing of a light aircraft (Mooney M20) at an average cruising speed typical of a small commercial aircraft. During the experiment, the drone collided with the front edge of the wing and instead of bouncing it plunged into the metal, bent the stringers and damaged the internal pipe.
The drone went completely inside the wing. The investigators argued that such damage in a real collision would not have had serious consequences, but if the speed was greater (in the worst case), the drone could have caused the plane to fall with passengers.
Energetic response from DJI
In his letter, DJI observed that the maximum speed of a Mooney M20 light piston aircraft is 322 kilometers per hour. This means that the Phantom 2 drone had to fly at a speed of at least 62 kilometers per hour, while the speed limit for this unit was 54 kilometers per hour. This means that even if all the worst conditions are present, the collision speed of the drone and the aircraft would be lower than in the experiment.
In addition, the Chinese company observed that aircraft generally reach high speeds at heights that drones do not reach, which would mean that in real conditions there would be no such collision at all. In the case of the Mooney (DJI speaks of a model J of 200 horsepower that took place from 1977 to 1987), the maximum speed of cruise of the aircraft is of 322 kilometers per hour, and the speeds of takeoff and landing are 130 and 163 km / h respectively.
DJI also noted that researchers at the University of Dayton Research Institute (UDRI) in Ohio, USA, obviated the recommendations of the Federal Aviation Administration of the United States in terms of resistance tests of aircraft collision with birds (still not have developed recommendations for such tests with drones). Such recommendations indicate that the tests should be performed at the cruising speed of the aircraft, which is notably less than 383 kilometers per hour for the M20.
On the other hand, the researchers of the aforementioned University did not disclose details of the research methodology and did not specify the model of the Mooney M20. The Chinese company seems to be arguing reasonable arguments, taking into account that the modern version of the Mooney M20, the M20V, produced in 2017, has 280 horsepower and reaches a top speed of 362 km / h, and has a maximum speed of cruise of 324 km / h.
Currently, there is no international consensus on a clear method to determine the danger that drones can pose to airplanes and helicopters. Aviation authorities in several countries around the world, including the United States and the United Kingdom, are conducting several studies, the purpose of which is to determine the danger of unmanned aerial vehicles for manned aircraft and to develop recommendations to test the resistance of aircraft. airplanes and helicopters to collisions with drones.
In November of last year, an ASSURE study determined that drones represent more danger to aircraft than birds. It was found that the turbines are the most resistant, while the front edges of the wing and engines could be severely damaged.