Rust is obviously a helicopter, I couldn't tell you what kind, xD he started as a gag; in class a friend was like "you're a helicopter" to my joke regarding helicopter discussions; however I replied sarcastically, "I'll show you helicopter" and did this (not as detailed) sketch of a helicopter dude and thought it was pretty cool looking, so I continued on it and didn't stop because I thought it was cool. Yeah. Rust :3 I made up a term for "rust" and made it Recon Unit Service Technology and that's how he got his name.
"Ladies and gentlemen may I present to you the future in technology as we know it;" dramatic pause. "RUST" unveiling. Lol