Near collision with drone
Only an estimated ten meters were missing - then a collision between a drone and a Swiss Airbus would have occurred during the approach to Kloten.
The incident happened a while ago - it occurred on May 6, 2017, according to the recently published report of the Swiss Safety Investigation Authority (Sust) from early October.
Only 10 meters away
What had happened? The scheduled Swiss flight from Dar es Salaam, Tanzania, is en route to Zurich with 185 passengers and twelve crew members. The A330 is on approach to runway 34 when the flight crew of the aircraft ahead informs the traffic control center that something like a drone has been spotted at the A330 behind them. Both pilots of the Swiss aircraft immediately keep a lookout and recognize a drone for about two seconds, which is in the approach axis and at the same altitude. (about 5000 feet). Then the A330, which is in the process of landing, flies an estimated ten meters below the unmanned aerial vehicle.
According to Sust, it is striking in this case that the drone was above the MILNI waypoint (cf. figure, marked in red) at approximately the altitude of 5000 feet expected according to the ILS approach. It is thus conceivable that the position and altitude of the drone was deliberately chosen with the intention of taking close-up pictures of commercial aircraft.
In the case in question, it is said to have been a drone with several rotors (multicopter) and a diameter of about one meter. "There was no time for an evasive maneuver," according to the Sust report.
Collision could lead to fire
Despite timely warning by the crew of the preceding aircraft, it was not possible for the A330 to detect the drone in the approach axis at an altitude of around 5,000 feet in good visibility conditions. Consequently, it was not possible to avoid the drone within such a short time.
A similar situation occurred on the approach to runway 33 in Basel on July 14, 2016. At that time, too, a drone was sighted, and the pilot did not have time to take evasive action.
For Sust, it is therefore clear that drones must be technically recorded and aircraft warned (cf. also here). Otherwise, a collision with a commercial aircraft at low altitudes is only a matter of time, because the number of drones is increasing rapidly. Multicopters of this size in particular could cause considerable damage to an engine or even set it on fire. They thus pose a threat to commercial aviation, the Sust report states unequivocally. (rs)
