Here are three simple ways to say that sentence for a 6-year-old:
- Brave people fly in airplanes up in the sky. They go far quickly to bring help or a package.
- Brave flyers zoom through the sky in flying machines. They can reach far places fast to help someone or carry a package.
- Brave people ride in flying machines to get to faraway places quickly and give help or deliver a package.
Step-by-step: 1) Who? Brave people. 2) How? They fly in airplanes or flying machines. 3) Why? To get far away fast and bring help or a package.