Almost two-thirds of pilots who received alerts of a potential mid-air collision with another plane were found to have responded incorrectly, prompting labor groups to issue a warning and ask for more training.
According to a report by Eurocontrol, which is responsible for the oversight of European airspace, only 38% of aviators in the region followed the correct procedure when notified of a potential incident by a plane’s Traffic Collision Avoidance System. Eurocontrol examined 1,184 cases over a 12-month period.
TCAS has been credited with dramatically reducing the risk of planes colliding during flight and is required on all airliners around the world. The device communicates with systems on other jets and, if a collision is imminent, either tells pilots to climb or descend. Yet in practice, more than one-third of pilots did the opposite of what they were instructed, the data show.
The findings prompted the International Federation of Air Line Pilots’ Association and International Federation of Air Traffic Controllers Association to issue a joint advisory to their members, telling them to follow the commands and not assume aircraft they can see outside are the ones on the TCAS display. Aircraft operators and training providers should make the practice the focus of recurrent sessions, they said.
Following Instructions
The system was designed after several high-profile mid-air collisions in the U.S. that occurred in spite of efforts by air-traffic controllers to keep planes apart. It began to be required on aircraft in the mid-1990s, and there have been few incidents since. The exceptions have mostly occurred when it wasn’t working or pilots didn’t follow its instructions.
For example, in 2002, a Russian plane collided with a DHL cargo jet over Germany, killing all 71 people on both aircraft. Part of the reason for the crash was that the Russian crew followed the instructions of an air-traffic controller to descend even though their TCAS was ordering a climb. The DHL pilots were also descending as a result of the TCAS and the two planes collided near the Swiss border.
