Brendan and his seven-year-old nephew

Brendan had spent a week visiting his family in Kentucky. His sister-in-law and seven-year-old nephew went with him when he returned to the airport.
After verifying his seat number with the counter attendant, Brendan walked back to his relatives and stated that he d have to wait an additional three hours in the airport.
“How come?,” his nephew asked.
“My plane has been grounded,” Brendan explained.
“Grounded?” the little boy said. “I didn’t know planes had parents.”