It was an alarming news when air traffic controllers that directed airplanes that come and passed through one of the most busy airports in the country repeatedly lost their radar and radio communications, but the pilots, independent air security experts and the federal aviation administration say that other redundant systems prevented the planes from colliding.
“I think the risk of a collision or an incident increased, but not significantly due to the redundancy in the aviation system,” said Jeff Guzzetti, former FAA accident researcher and the National Transport Security Board.
Shocks such as the deadly collision of January between a passenger plane and an army helicopter generally have different causes, a combination of many things that go wrong, he says.
Here is a look at what happened in Newark, and how the key pieces of the security network protected people’s plane.
The radar and communications systems on which a terminal control team in Philadelphia is based to direct the airplanes inside and outside the Newark International Airport failed simultaneously twice in the last month for brief periods. The main line that carries the radar signal from another FAA installation in New York failed, and the backing line did not work immediately. The system is based partly on the aging of copper cables and even when there are fiber optic lines, the signal must be slowed when it reaches the installation because FAA computers are so old that they cannot handle all data at full speed.
As a result, the controllers suddenly could not see or communicate with airplanes that come or go to Newark for 90 seconds in April 28 and May 9. Their radar screens that show each moving flight suddenly became black. His radio connections were silent.
The main line failed for the third time on May 11, but the backup system worked and the radar remained online. The FAA said that a fourth interruption on Monday eliminated radio communications for two seconds, but the radar remained online.
After the initial interruption, the control center already short in Philadelphia lost five to seven trauma license controllers. The Newark Terminal Control Team could no longer handle a complete transfers with the airport control tower, which leads to hundreds of flight cancellations and delays that extended through the country’s airlines. The FAA then imposed security limits, allowing no more than 28 arrivals and 28 exits every hour. Before, 38 or 39 flights generally took off and landed per hour.
When air traffic controllers lose the ability to see or speak with aerial plans, they can try text messages to pilots through data link systems or test high -power portable radios. An emergency radio frequency could also be an alternative if the main communications are low. The tower controllers have high -power light guns to send a green or red signal to the pilots to let them know if they are clear to land, even if they cannot talk to them on the radio.
And the entire air traffic control system is built on a superposed network of radar sites. Then, if a terminal control team such as Philadelphia loses its communications, a controller in a radar center that normally directs the highest altitudes could intervene. If any other controller in the area listens to a pilot transmission on an emergency frequency, they can also transmit a message.
During these philadelphia interruptions, voice communications were online first, while the radar took another minute to restart, and the controllers were able to deliver planes without having to resort to some of those other options.
In a recording of May 9 captured by www.liveatc.netYou can listen to a controller say “Fedex 1989. I will give you here. Our areas became black again. If you care about this, contact your airline and try to obtain some pressure to fix these things.” The pilot recognized him and wished the controllers “good luck” before changing the frequencies.
The interim administrator of the FAA, Chris Rocheeau, has tried to assure the public that all these backups and limits in the amount of flights are kept safe, despite these problems that have exposed how fragile and outdated some air traffic control systems have become.
“When interruptions are produced at any airport due to equipment or staff problems, FAA will always guarantee security by slowing down the arrivals and exits of the airport and reducing the congestion,” Rocheleau aware In X. “We keep the public flying safe because there are redundancies built throughout the system used by pilots, technicians and air traffic controls.”
Each pilot is trained on what to do if they cannot speak with air traffic controllers, and modern passenger aircraft have their own backup systems. Airline pilots regularly receive update training that emphasizes security.
Captain Miles Morgan supervises all training for 17,000 United Airlines pilots in a Denver installation full of simulators and classrooms. He said that losing communications is rare, but it is something that the pilots prepare, since most training focus on what to do if something goes wrong.
“I’ve been flying for 30 years. I have almost 18,000 hours in United Airplanes: Jets, and I lost communication once,” said Morgan. “It really ended up not being a big problem. I just went to the emergency frequency, I got a different channel and contacted a different installation to return to communication.”
In addition to multiple communications systems, airplanes are equipped with collision avoidance technology that shows pilots where all other planes are moving around them. These systems alert the pilots about the trajectory of an aircraft that is approaching and can recommend an evasive action to avoid a collision if the airplanes get too close, said Morgan.
The spokesman for the Union of the Association of Allied Pilots, Captain Dennis Tajer, said that when the pilots lose contact with the controllers, their first action is to continue in their last directed path. If the interruption continues, they will transmit their position to any other plane in the area, as well as the pilots in small airports that do not have a control tower, while their flight plans follow.
“It is not to minimize the severity of the communication failure or radar interruptions, but it is to recognize that we have procedures, we train those procedures and we have additional equipment that can only improve the safety margin while we treat that scenario,” Tajer said.
