Radar off and radio silence: so the controllers lost contact with planes for New York for 87 seconds, what happened

For a minute and twenty -seven seconds Philadelphia flight controllers They lost the audio and radar contacts with a dozen planes – with over two thousand passengers on board – which at that moment were under their supervision. Not to mention the others in approach and private jets. An infinite timealso because there was nothing to do if not to wait for the restore systems. When everything returned to work in the room of the control center, they were able to breathe: the aircraft were still at high altitude.

The blackout

These are some of the most incredible details of computer problem which occurred on 28 April at the « Tracon » (Terminal Radar Approach Control) in Philadelphia – the area control center that manages significant portions of traffic – which has led to impose For several hours the stop to the movements in one of the reference stops of New York. The news, revealed first by Bloombergis confirmed to the Courier From two people aware of the dynamic who also add the number of flights « involved » by the Blackout.

The cancellations

The effects still feel today. United Airlines – The main operator – is canceling on average 35 flights per dayone in ten among those scheduled, until the situation returns to normal. And it might want more time since – as the Federal Aviation Administration has clarified – « there is a lack of staff in the Radar Center: some of the controllers involved have taken a rest period to recover from the stress caused by numerous recent blackouts».

Inside the « tracon »

It all starts shortly after 13.30 local (19.30 Italian) of April 28th. At that moment the controllers of the section of the « tracon » of Philadelphia who are managing direct flights to Newark – such as the JetBlue 144 from West Palm Beach, operated with an Airbus A320 -, but also the Business Jets see their monitors suddenly turning off. They try to get in touch via radio with the pilots and realize that the communication system does not even work.

Screams and swear words

At that point – it is the story made in the chats with other colleagues from those who were in the room at that moment – they feel screams and swear words, The race starts to notify the other wings of the Radar Center so that it can slow down traffic, deviate the airplanes coming and try to avoid disaster in the skies. « Landing, are you there? », Do you hear from a pilot in the audio captured by the Liveatc site, referring to the controller who takes care of bringing planes closer to the airport from the ground. Try it five times before getting an answer from the Radar Center.

« Funds out of use »

A few seconds later, the Newark control tower contacts a United Airlines pilot in flight: «I will move you here because they just told me that theapproach has lost all the radar», He communicates to him. « Three of their four radar screens have turned off and have no active frequency, » he continues. Another conversation captures the moment of uncertainty. « There are some out of use equipment, I don’t know exactly what they arebut they are having problems with frequencies, « says a controller. All you be able to wait for the intervention of the technicians and the restoration. Which happens. The interruption lasts eighty -seven seconds.

« I don’t know where you are »

Some problems, around 13.45 remains. « The radar does not work, we don’t know where you are, » says a controller from the ground to the pilots of the United flight from Charleston to Newark, asking to look around. For the fear of other disservices and to avoid accidents at 13.53 the FAA imposes the « ground stop » on Newark: all the departure airports are blocked all the direct planes in the airport that serves New York. The stop lasts until five in the afternoon. In the meantime, there is a need to replace the 5 flight controllers who have stopped working « for the trauma » suffered.

The absence of redundancy

« The only positive aspect of the story, if you can say so, was the timing – reveals one of the sources -: everything happened at a time where the volumes are not at the maximum levels of the day and the separation (the distance, editor’s note) Among the jets it is usually greater ». The computer structure of some US radar centers is so old that there is no « redundancy »: if a blackout occurs, no parallel interface does not take place for which it is only expected that everything will return in operation.

Confirmation

« The colleagues of the Filadelphia structure temporarily lost radar and communications with planes under their control, failing to see them, hearing them or talking to them », confirms the National Air Traffic Controllers Association in a note. Which makes it clear that it was not the first interruption. However, some experts report that these are really particular problems and potentially dangerous. The United States Transport Secretary, Sean Duffy, said that communications « were interrupted for 30 seconds and that no plane has been in danger ».

The impact on Newark

Since then they have been Over 400 flights deleted and more than 1,500 those late in Newark onlyaccording to the FlightWare platform. While the CEO of United, Scott Kirby, in a message to customers wrote that « for many years we have been very clear and we reiterated the need to improve the Newark air traffic control system ». System that, he added, « in the last few days, on more than one occasion, he has had problems ».

The FAA approach

Faa explained that He is « working to ensure that current telecommunication equipment are more reliable in the New York area ». And he recalled that « when personal or equipment problems occur, the federal aviation body will guarantee safety by slowing down the rhythm of arrivals to the airport ».

The lack of controllers

La Faa did not mention the (chronic) deficiency of flight controllers: throughout the country About 3 thousand are missing from the level deemed optimal And to form the new ones you need time. Not only that. « In recent decades, the Federal Aviation Authority has faced difficulties related to the aging of air traffic control systems », reads a last December report by the Government Accountability Office.

Old platforms

« These systems will have to cope with a growing demand, given that the FAA provides for an average annual increase in traffic by 6.2% ». According to TSA in this period in the USA about 2.5 million people fly per day fly. In the « census » of 2023 the FAA established that of the « 138 air traffic control systems, 51 were unsustainable and 54 potentially unsustainable ». To read the list there are about forty installed over 30 years ago and even six more than 60 years ago.

How it works in Europe

« The systems of the control centers in Europe all have a backup », explains to Courier A veteran with over thirty years of experience. « Antiquated systems such as those of the FAA, far out of the European ones, They may have simultaneous malfunctions, « he continues. But the expert emphasizes that we must better investigate the technical causes. And he adds that « the most advanced systems, also in use in Italy, have the CPDLC (Controller Pilot Data Link Communications) which allows air traffic controllers to communicate with pilots through a data communication system. In this way it is not necessary to contact the pilots via radio ».