People sometimes forget how to behave when they're on a flight. But what's the very worst thing a fellow passenger can do?

London City Airport surveyed 232 travelers to find out their greatest sources of irritation while onboard.

The results, published Wednesday, show that excessive seat-reclining is the biggest no-no, with 63 percent of passengers saying it was one of the most annoying things they encounter during air travel.

The frustrations are further detailed in this infographic: