Air traffic across Italy was heavily disrupted Friday by a data-transmission network failure supporting air traffic control, delaying and cancelling flights, including services run by Ryanair, as a 24-hour strike by EasyJet staff added to the chaos.

Civil-aviation authority Enav said air traffic management capacity was down by about 50% because of anomalies in the network, which began overnight. It said that from 6 a.m., flow-regulation measures were introduced as air traffic increased and the problems persisted, temporarily reducing the number of aircraft that could be handled in Italian airspace.

Enav ruled out a cyberattack or sabotage. It said technical checks, still under way, traced the origin of the problem to the data-transmission network and that it was working to identify the causes and restore full operations.

Ryanair affected

Ryanair flights were among those caught up in the delays at several airports.

At Orio al Serio airport in Bergamo province, the carrier’s 6:50 a.m. flight to Trapani took off an hour and a half late. Another Ryanair flight, to Berlin, was delayed by one hour and 20 minutes.

At Lamezia Terme airport in Calabria, delays reached three to four hours. A Ryanair flight scheduled for 7 a.m. was still waiting to depart, as was an Ita flight to Milan Linate set for 6:35 a.m. A Ryanair flight from Turin due at 11 a.m. was canceled.

At Trieste Airport, a Ryanair flight and a Tirana connection were not affected for the time being.

EasyJet strike

Air-travel specialist RimborsoAlVolo said the technical problems were compounded by a 24-hour strike called by EasyJet staff. Guaranteed service windows, from 7 a.m. to 10 a.m. and from 6 p.m. to 9 p.m., require flights to operate during those hours.

Because the strike was called by airline personnel, passengers are entitled to cash compensation of 250 to 600 euros if a flight is canceled or if they reach their final destination three hours or more late, according to RimborsoAlVolo, citing a European Court of Justice ruling.

Passenger rights

Under European regulation 261/2004, passengers are entitled to refunds and assistance, even in exceptional circumstances, RimborsoAlVolo said. If a flight is delayed for a long period or canceled, the airline must provide meals and drinks, transfers and hotel accommodation if needed.

For flights canceled because of the technical problems, airlines must offer a choice of a ticket refund, with a return flight to the departure airport if the passenger has a connection; rebooking on another flight to the final destination as soon as possible; or rebooking on a later date.

Cash compensation does not apply to the technical failure, said Kathrin Cois, RimborsoAlVolo’s managing director. Because it is considered force majeure, the delay or cancellation is not the airline’s responsibility, she said.

Other airports

At Rome’s Fiumicino airport, four departing flights, to Milan Linate, Riyadh, Tirana and Trieste, were canceled at the time of writing, while about 20 others were delayed by 15 minutes to an hour. Airport operator ADR told passengers to check their flight status with their airline.

At Milan Malpensa, the departures board showed delays from 30 minutes to more than two hours. At Linate, arrivals were delayed by 20 minutes to an hour and departures by more than an hour. Flights at Calabria’s Reggio Calabria and Crotone airports were running normally.