The Reason Planes Don't Fly In Fog

Severe fog delayed over 132 flights at London’s Heathrow airport this weekend leaving thousands of travellers stranded in the airport while waiting for the fog to lift. But why can’t planes fly in fog?

Planes can fly in fog

Well, contrary to popular belief, planes CAN fly in fog. The fog doesn’t affect any of the airplanes equipment. Engines will still function perfectly, radars still operate as usual and all other technology is also unaffected. However one there is something that doesn’t work well in thick fog – our eyes.

Eyes

Even though there’s plenty of technology on board planes to help enable them to make blind landings, most pilots still rely on their eyes to judge how to approach the runway. When visibility is low the captain can’t spot potential dangers until they’re close to the object, at which point there is limited time to make a decision on how to avoid the hazard.

Air Traffic

In fog air traffic controllers will increase the airspace between planes so that there’s more time to react if anything goes wrong. The increase in space between aircrafts means that fewer planes can use the airport, leading to delays and cancellations.

Danger

Many people will be frustrated with the delays thinking that airport’s are being over cautious. However, fog presents a real danger. The last collision caused by fog happened in Milan in 2001 when a passenger jet speeding down the runway collided with a light aircraft, killing all passengers on both planes, totalling 118 deaths. The air traffic control team were found to be negligent and received prison sentences ranging from 3 to 4 years each.

Conclusion

So, the real reason that fog grounds so many flights is simply for our own safety. We may have all kinds of technology on aircrafts but nothing can beat human intuition and the judgements made by our own eyes, especially when so many lives are at risk. So next time you’re delayed by the fog just remember that it’s for your own safety, grab a coffee from the departure lounge and enjoy a good book while you wait for the fog to lift.