There is a fine line between aggressiveness and over-aggressiveness at takeoff. One of the most common mistakes made by athletes, including those at world class level, is to raise the ski tips too much during the transition. This excessive angle of attack causes the skis to act more as a spoiler than an efficient aerodynamic device to cut through the air, resulting in more height than distance. Conversely, if an athlete over-rotates and leans too far forward between their skis, they will sacrifice height as well as distance. In a well-executed jump, athletes will spend several seconds longer airborne than in ski jumping – up to five seconds more – which requires a different level of skill in order to sustain flight for a longer period, and showcases how the role of aerodynamics is magnified in ski flying. Not all athletes who excel in ski jumping are able do so in ski flying (see the section on specialists), and it can be difficult for them to hone their skills in the latter due to the hills being off-limits when competitions are not staged.