Why would he say "grounded"? Is it because they've got crash-landed?
Native speaker’s answer
Rebecca
Yes, that's correct! "Grounded" is used to refer to aircraft that fly, like planes. If a plane is unable to fly or leave the ground, it is "grounded." Ex: The plane has been grounded due to heavy rain. Ex: My plane was grounded for over two hours because of a snowstorm.