Police said the male passenger walked onto the wing of Flight 2478 and then slid down onto the airfield, police said.
The judge who handled the case was shocked it took three months to catch the man.
"We were so lucky they didn't get sick," said mothers of traveling students. "Then at the Chicago Airport, they're packed like sardines."
Some expressed health concerns because they were standing next to hundreds of people and couldn't socially distance themselves.
A plane slid off a runway as it was landing at O'Hare Airport as snow fell on the Chicago area Monday morning, officials told ABC7.