Air traffic controllers' indefinite strike causes delays at Lanzarote airport; unions say tower has 14 of 22 required controllers

A labor conflict between air traffic controllers at private concession company Saerco and the company's management has caused delays at César Manrique-Lanzarote airport since the night of November 4. Eurocontrol records show only two European aerodromes currently experiencing serious delays: Athens, for local causes, and Lanzarote. At Lanzarote, 2,225 minutes of accumulated delay have been recorded due to air traffic control strikes, nearly 5% of total delays in the European airport network.

Susana Romero, national spokesperson for the Air Traffic Controllers' Union (USCA), said the indefinite strike, called jointly with Comisiones Obreras (CCOO) for the nine towers Saerco manages in Spain, began in April. Until now it had been described as an "invisible strike" because minimum-service resolutions required practically all available staff to work; the unions have challenged those decrees in court for violation of the right to strike. For Lanzarote, resolutions of the Ministry of Transport and Sustainable Mobility set protections of 76% in October and 73% in November for island flights.

The winter high season has made the strike visible. In single-controller towers such as El Hierro, the sole controller on duty is bound by decree to the minimum service, but in larger airports like Lanzarote, schedules require several staff per shift in high season. Romero said there are now more often two controllers in Lanzarote because of winter traffic volume, and sometimes one can exercise the right to strike, which is why delays are now appearing.

USCA says it is not demanding pay increases but more staff. According to the strike committee, the César Manrique tower operates with 14 active controllers versus the 22 technically required. The unions say the shortage leaves no room for maneuver in cases of medical leave or traffic peaks, compromising regulatory breaks, work-life balance and service stability, in contrast with the period when the towers were run by public entity ENAIRE, even though traffic has grown significantly since the pandemic.

Romero separated the workload and the strike from two recent incidents on Canary Islands runways. She said the runway incursion in Lanzarote resulted from an interpretation error by the aircraft's crew, which believed it was authorized to enter the runway, and that it was reported for technical analysis without compromising safety.

USCA and CCOO demand a comprehensive review of the privatization framework for the nine state-level concessioned airports. If the concessionaire does not guarantee stable and sustainable staffing, the unions say they will formally ask the Government to revoke the contracts and return the towers to direct public management by ENAIRE. In the Canary Islands, Saerco manages the control towers at Lanzarote, Fuerteventura and La Palma, plus the Aerodrome Flight Information Service (AFIS) at El Hierro and La Gomera.

The Lanzarote case shows how a strike can stay nearly invisible while minimum-service decrees absorb most available staff, then become operationally visible once seasonal traffic requires more controllers per shift than a thin roster can supply. The delay figure at Lanzarote arrives only when winter scheduling and the staffing gap coincide.

For operators and airports in a concession model, the exposure is structural: a tower running well below its technically required headcount has little buffer for leave, peaks or industrial action, and the protection percentages set by the ministry decide how much of that exposure reaches passengers. The unions' court challenges to those decrees and their threat to seek contract revocation are the two threads that would change the balance.

The next signal is whether the Government responds to the request to review the concession framework, and whether the minimum-service levels set for the coming months move from the 73% applied in November.