Modern multi-blade drones do this very thing : attitude, altitude and heading hold. They are incredibly stable, and even have a "return home" feature, obstacle avoidance, and more. Very sophisticated.
Could this be adapted to a full-size craft? Possibly, but that's a serious engineering task that would involve a lot of development and testing.
For that reason, I think it is exceeding unlikely to think a 78 year old man, ill with cancer, would invent and equip a 3-axis fly-by-wire guidance control/autopilot system for a helicopter so he could rappel down and hide a treasure while a helicopter hovered overhead. Then after securing the treasure, he would presumably climb the rope to re-enter the craft, disable the attitude hold then fly away.
This sort of thing is best left to the James Bond films.
Could this be adapted to a full-size craft? Possibly, but that's a serious engineering task that would involve a lot of development and testing.
For that reason, I think it is exceeding unlikely to think a 78 year old man, ill with cancer, would invent and equip a 3-axis fly-by-wire guidance control/autopilot system for a helicopter so he could rappel down and hide a treasure while a helicopter hovered overhead. Then after securing the treasure, he would presumably climb the rope to re-enter the craft, disable the attitude hold then fly away.
This sort of thing is best left to the James Bond films.