Can you fly in storms?

Your question of the month in September (2016)
Marie (9) from Hamburg

For pilots, meteorology is an important part of their training. By judging the weather correctly and constantly observing the clouds, pilots can, for example, determine what kind of clouds they will encounter on a flight and whether it is better to fly straight through them or around them.

Completely gray sky? Rain? Yuck! But what does it mean for pilots?

This kind of weather often happens when there is a warm front coming in: The (somewhat) warmer air gradually pushes against the cold air, cools at altitude and forms clouds – meteorologists call them strata clouds. We might not find it so nice, but it actually means stable weather for pilots. The only thing pilots have to worry about is the water – large amounts of water collect in the clouds and at altitude it can freeze and become ice. When water freezes on wings, this makes the aircraft heavier and the air resistance, or aerodynamics, changes. But don’t worry, all commercial aircraft are equipped with special systems to protect against ice. They blow warm air from the engines onto the front edge of the wings so that no ice can form. This means that pilots can simply fly through strata clouds.

Summer, a blue sky with small white fluffy clouds – perfect weather for flying, right?

In summer, the first small white fluffy clouds form in the morning and develop into larger cumulus clouds throughout the morning and afternoon. What looks pretty to us on the ground is not necessarily good for pilots: They mean that large masses of air are moving around, much more so than you might think. These can sometimes rise very quickly at up to 50 kilometers an hour. These can shake an aircraft around a bit.

When one of these fluffy clouds becomes a cumulus cloud or even a tower of cloud, the pilot normally decides to divert and fly around the cloud as forces in the clouds due to upwinds and downwinds can be very strong and lead to unpleasant, strong turbulence.

But what about storms?

Every commercial airliner has a weather radar. With the weather radar, storms are easy to see (even at night). Lightning is always part of a storm. When large masses of air move, there is a lot of friction and that turns into ... you got it! Lightning. But lightning isn’t actually too bad for an aircraft as the outer shell functions as a Faraday cage: this was named after its founder, the researcher Michael Faraday. In an experiment, he found out that in an enclosed space that is surrounded by metal on all sides, you are protected from lightning.

This means that when a flash of lightning hits a metal cage, for instance an aircraft, it is conducted around the outside and cannot penetrate the inside. If an aircraft flies through a storm and gets hit by lightning, the metal will conduct the lightning around the outside and to the rear of the aircraft.

The bigger problem with storms is hail. At the great heights and speeds at which aircraft fly, hail may damage the aircraft, but generally the damage is not too bad and will be repaired after landing.