ELi5 Why are planes grounded when there is fog but they can fly through fog and clouds.

Question

I dont understand when they have control towers and such advanced technology why fog can ground planes. Not much is done by eyesight now surely?

In: Technology

Answer 1

It depends on who is flying. Most commercial airliners/pilots are rated for instrument-flight, meaning they can fly in adverse weather conditions like fog or night-time. But for private or charter planes/pilots, they may not be rated for that, so they can only fly when it’s clear skies.

Additionally, there is increased risk. Take off and landing are the most dangerous times in a flight. A plane in flight can’t really do that much to get out of clouds/fog; additionally, there’s not much else to run into at 30,000 ft above sea level. But, near the ground, there are a lot more hazards, so it’s a lot safer to wait for clear(er) weather before taking off to minimize the risks during the already-riskiest part of the flight.