I’m sorry if this has already been asked. I searched but couldn’t find anything.
I have a problem where I need to fly a fixed-wing drone carrying a heavy, expensive, and extremely rugged payload, (let’s imagine it’s a solid gold Nokia 3310). This means that if anything at all goes wrong with the plane, I don’t want it to circle or loiter, and I definitely don’t want it to soar off into the horizon, never to be found again. It’s much better for it to do a controlled dive into the ground, even if it means the drone dies. There are no people or buildings in the area where I fly, and nothing that can catch fire. The area has sand and salt water. I want to avoid it flying into an area where there actually are people, and I definitely want to avoid it going out to sea where it will surely sink to the bottom.
Circling and loitering are not good options.
How can I force the plane to dive straight down?