OR Tambo International Airport’s passengers were hit by weekend flight delays after air traffic flow restrictions disrupted departures and arrivals, forcing airlines to manage knock-on effects across schedules and connections.

Air Traffic & Navigation Services (ATNS) first went public in a media statement on Sunday, saying it was aware of delays “currently being experienced” at OR Tambo, South Africa’s busiest airport and the second-busiest in Africa. ATNS said the delays were “primarily due to temporary human resource constraints at the air traffic control station” and added that “contingency measures have been implemented” while “additional resources are being deployed to stabilise operations”. It said the interventions were expected to “resolve the situation today” and “progressively restore normal service levels”.

ATNS is a state-owned company that monitors and controls South Africa’s airspace.

ATNS published a follow-up update on Monday, informing travellers that “the entity can also confirm that the human resource constraints experienced yesterday at the air traffic control centre have been resolved and the operations have been stabilised with no staffing challenges anticipated.” It told travellers that air traffic operations at OR Tambo were “normal this morning, with services continuing as planned”, while noting that aviation requires “constant close monitoring and evaluation”.

In that same update, ATNS also addressed reports of diversions, saying the diversions “were not caused by human resource constraints” but were instead due to “severe weather conditions, including thunderstorms,” which temporarily affected safe aircraft operations in the OR Tambo airspace.

A separate ATNS statement, also published on Monday, pushed the reassurance further, saying the “human resource constraints experienced yesterday” had been “resolved” and that operations had been stabilised with “no staffing challenges anticipated.” ATNS said it had “successfully cleared the backlog emanating from Sunday’s operational challenges” and that “there are no anticipated delays,” while warning that bad weather could still lead to diversions because safety would be prioritised.

An insider told The Common Sense that the delays were caused by severe staffing shortages at ATNS. The shortages have arisen for reasons including weak management, affirmative action, ageing systems, and better career opportunities for experienced staff overseas.

The government has created a committee to monitor the problem but without addressing all its causes, industry insiders say the problem was likely to persist.