This article has been amended since it was originally published.
OR Tambo International Airport (JNB) experienced widespread flight delays and diversions on the afternoon and evening of January 4, with airlines working to recover schedules yesterday (January 5). This was due to a shortage of air traffic controllers, suspended instrument flight procedures and inclement weather conditions.
An Airlink spokesperson explained that ATNS only notified airlines on Sunday morning, after it had already begun delaying flights and restricting traffic, that it was experiencing staff shortages and would implement gaps between departures. Additionally, it planned a formal traffic restriction starting at 15h00 due to expected thunderstorms.
ATNS implemented aircraft start-up delays in the morning and increased departure times between aircraft to three minutes and later to five minutes due to staff shortages, all prior to the storm.
Airlink reported 31 delayed departures at JNB, which ATNS ascribed to staff shortages and flow control. These triggered a further 69 delayed flights throughout the rest of the day, with an average departure delay of 74 minutes.
“Today’s (January 4) schedule disruptions have had a ripple effect on all of our flights. In addition to departure delays from JNB, the shortage of air traffic controllers prompted a restriction on the number of flights permitted to be in Johannesburg’s airspace at any given time,” said Airlink.
“The delays stem from ATNS’s failure to ensure it has sufficient staff to accommodate and manage the normal scheduled traffic to and from JNB.”
Additionally, Airlink was forced to divert five flights yesterday, four to Gaborone and one to Durban, because of the weather, leaving it with aircraft and flight crews out of position.
“There are still multiple delays playing out this morning (January 5), as a number of aircraft and crews were left out of position overnight,” said the airline.
Airlink pointed out that a number of departure and arrival instrument flight procedures for JNB remained suspended, including some that were withdrawn as recently as December 9, after ATNS failed to renew their validity before they expired.
FlySafair’s Chief Marketing Officer, Kirby Gordon, reported that the airline’s on-time performance (OTP) rate for January 4 was 55%, falling far from its recently achieved average OTP of 91% for 2025, awarded by Cirium. Gordon explained that this indicated that 91 of 199 flights were delayed.
“This was a frustrating day for travellers, particularly during one of the busiest periods of the year for family and holiday travel. A large number of flights across all airlines were affected, resulting in widespread disruption for the travelling public.
“While the situation has since stabilised, the impact on customers was significant, and we are grateful to those who showed patience and understanding while operations were under pressure. This is an issue that we believe needs to remain a key industry focus going into the new year; it must be resolved.”
According to ATNS, the delays were primarily due to temporary human resource constraints at the Air Traffic Control station. ATNS confirmed that contingency measures had been implemented and additional resources had been deployed to stabilise operations.
However, ATNS Head of Corporate Affairs and Communications, Mphilo Dlamini, clarified on January 5, that the diversions from landing at JNB on January 4 were caused by severe thunderstorms during the afternoon.
“ATNS further clarifies that the flight diversions experienced yesterday afternoon were not caused by human resource constraints, but were the result of severe weather conditions, including thunderstorms, which temporarily affected safe aircraft operations within the JNB airspace,” said Dlamini.
