Dense fog disrupts OR Tambo flights as aircraft diverted to Lanseria

Poor visibility forces runway restrictions, causing delays for travellers

Passengers travelling through OR Tambo International Airport on Monday morning faced delays and unexpected changes to their journeys after thick fog reduced visibility, forcing several incoming flights to divert to Lanseria International Airport.

The weather-related disruption affected both arrivals and departures as air traffic controllers limited operations to a single runway to ensure aircraft could land and take off safely.

Flights diverted as safety takes priority

According to Airports Company South Africa (Acsa), dense fog over Johannesburg significantly reduced visibility during the early hours of Monday morning, making normal airport operations impossible.

In a notice to passengers, Acsa advised travellers that some flights could be diverted to alternative airports while others were likely to experience delays.

The airport operator urged passengers to check directly with their airlines before travelling, stressing that safety remains the highest priority during adverse weather conditions.

FlySafair among affected airlines

Low-cost carrier FlySafair confirmed that its operations had been impacted by the morning fog.

By mid-morning, the airline reported:

• Two flights diverted to Lanseria.
• One flight delayed.
• Reduced airport capacity because only one runway was in use.

The airline said forecasts from the South African Weather Service (SAWS) suggested conditions would begin improving later in the morning as temperatures increased.

Why fog causes flight delays

Aviation weather observations showed visibility at OR Tambo dropping to as little as 150 metres in some areas of dense fog.

When visibility falls this low, aircraft require greater separation during take-offs and landings. This means fewer flights can use the runway each hour, creating delays that can quickly ripple through airline schedules.

In some cases, pilots may be instructed to divert to another airport if conditions remain below safe operating limits.

On Monday, Lanseria International Airport, located northwest of Johannesburg, served as the primary alternative for diverted flights.

A common winter challenge on the Highveld

Morning fog is a familiar feature of winter in Gauteng, particularly across the Highveld.

Known as radiation fog, it develops overnight when clear skies and calm winds allow the ground to cool rapidly. As the air near the surface cools, moisture condenses into tiny water droplets, creating dense fog that can dramatically reduce visibility.

The fog usually lifts a few hours after sunrise as warmer temperatures disperse the moisture.

Travellers react online

Many passengers took to social media on Monday morning to share updates about delayed departures, aircraft holding patterns and unexpected landings at Lanseria.

While some travellers expressed frustration over disrupted schedules, others acknowledged that diverting flights is a routine aviation safety measure whenever weather conditions fall below operational limits.

The incident also prompted reminders from frequent flyers to check airline notifications before leaving for the airport, particularly during Gauteng’s winter months when early morning fog can develop with little warning.

Advice for passengers

If you’re travelling through OR Tambo during winter mornings:

• Check your flight status before leaving for the airport.
• Allow extra travel time in case of delays.
• Keep airline notifications enabled for updates.
• Be prepared for possible schedule changes if weather conditions deteriorate.

Although Monday’s disruptions caused inconvenience for many travellers, airport authorities expect normal operations to resume once visibility improves, with airlines working to clear any backlog created by the temporary runway restrictions.

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Source: iol.co.za