Tiltrotor: An aircraft that takes off vertically like a helicopter, then rotates its two giant propellers to fly horizontally like an airplane. The concept dates from the 1930s, but the first successful prototypes didn’t fly until the 1950s. Here’s a link to a YouTube clip promoting the military Bell V-22 Osprey, because a video is worth a thousand words.
Tiltwing: Same idea, but on this variant, the entire wing rotates, not just the engine nacelles. Orienting the wing vertically for take-off reduces drag and allows for better climb performance in VTOL mode, but adds complexity and weight. I’m going to use the term tiltrotor to include both kinds.
Both formats have a size limitation that is probably insurmountable. You can only make rotors so big, so we’re not likely to see a tiltrotor much bigger than a bus. Trying to build one with more than two rotors just gets crazy.
Tech Level: High, as it works best if you have both turbine engines and computers for flight control. Best genre fit: Military or Near Future SF. Also a good choice for post-apocalyptic recovery, where humans retain a few hubs of technology and work to rescue survivors from isolated pockets.
Appeared In: The cyberpunk anime movie Ghost in the Shell and the anime series Read or Die both used tiltrotors in urban environments. The cartoon Martin Mystery (half Canadian, eh!) employed a ducted tiltrotor in wilderness settings. I think what makes the tiltrotor a favourite with animators is that it’s easier to show than tell. Where a written description of the machine’s transition from vertical to horizontal flight would be cumbersome, animation makes it instantly understandable.
For Your Plot: Vertical Take-Off is very handy for getting around without infrastructure like runways. That makes tiltrotors a natural for exploring or colonizing new worlds. Take your heroes swiftly to unexplored parts of the planet, and drop them into the places where the planetary survey charts say, “Here be dragons!”