The Varga family has its own private jet. But Ross rented another from one of his closest friends to avoid getting attention.
This jet is not ordinary, but it has a special place in his heart because he was present when his friend, Zion Dawson, met the aeronautical engineers to design his private jet, to whom the latter asked his ideas.
Ross then suggested that a private cabin and shared lounge must be separate to ensure complete privacy for the executive passengers. He didn't expect Zion to follow his ideas.
Moreover, Zion built more private jets that he sold to their elite friends. Ross then invested in Zion's new business. Hence, he wasn't just renting a plane; he was also earning.
Therefore, Ross has already instructed Andrew that the private lounge was off-limits to the flight crew and medical team—unless they were requested to serve and check on Yonah.
Hence, Ross wondered.