Originally Posted by Long Zhiren

In Aerospace engineering, a flight cycle is defined by number of landings, not the number of anything else that happens during a flight.
And by blunt definition, a landing, is just a controlled crash. It's a very violent structural loading. The aircraft's structure gets its most severe loading, maybe the only significant loading, when it comes in dynamic contact with the ground. Try playing in a flight simulator some time. If anything is really tricky, it's the landing.