Also, we must remember that this is the middle of summer. These kids wanted an adventure, beyond spending all day at the pool, taking karate lessons twice a week and stuffing their pie holes with milk shakes, beef burgers and hot dogs all day long.
Traveling by air is perhaps one of the safest and yet at the same time most fulfilling adventures a kid can undertake. One is never left alone, and once one passes the security checkpoint, one is in a "secure" and controlled environment. Additionally, the mode of transportation itself is much safer than crossing the road or riding a bike through the countryside.