Yes, Prince William frequently travels on the same aircraft as his children, although this technically breaks an unofficial royal protocol. Traditionally, the "no two heirs should travel together" rule exists to protect the line of succession in the event of a tragic accident. As the Prince of Wales is the immediate heir to the throne and Prince George is second in line, they would traditionally be required to fly separately. However, Prince William sought special permission from Queen Elizabeth II (and later King Charles III) to travel with his family to keep them together during long tours to places like Canada, Australia, and Poland. This relaxation of the rule is largely due to the significant increase in the safety of modern aviation compared to the mid-20th century when the protocol was more strictly enforced. It is expected that once Prince George turns 12 (which will occur in July 2025), he may be required to begin flying on a separate aircraft from his father more regularly to satisfy constitutional safety standards, a transition Prince William also made when he reached that same age.