Author: John Cox, Special to USA TODAY

Why does it seem like more aircraft are sliding off runways and taxiways?

Runway length is carefully calculated before every takeoff and landing.

With modern airplanes and well-trained pilots and ground staff, we fly safely in challenging conditions every winter.

Ferry flights often use remote airfields for refueling. For the North Atlantic, flights may include fuel stops in Canada, Greenland and Iceland.

The Digital Flight Data and Cockpit Voice recorders have proven to be very successful over the decades.

Airlines flew nearly 4.5 billion passengers on nearly 45 million flights worldwide, both records. But there were 15 accidents worldwide.

Pilots fly many different airplanes of the same model within a fleet. While there are some differences, they fly pretty much the same.

Modern airplanes are designed to withstand heavy turbulence without damage.

A diversion to land at an alternate airport is often misreported as an emergency landing. There is no emergency, but there is a change in plans.

Dutch roll is a natural aerodynamic phenomenon in swept-wing aircraft, caused by having slightly weaker directional stability than lateral stability.