First of all, I already agreed in the initial post that it would require some experience with helicopters. Second, in this case, "giving it a new input" could b

First of all, I already agreed in the initial post that it would require some experience with helicopters. Second, in this case, "giving it a new input" could be as simple as "changing the standing rotor speed -- 5500 RPM instead of 6500 RPM". They're so finicky, you don't need to specify a complex time history to hit a dangerous resonant mode-- though it certainly helps! Third, the fact that it's a gift is not at all required for an analogy. Of course you don't have to keep that part, and would have to reframe it so that the details of how the helicopter is provided a new input are different. You're not even trying to be charitable at this point, but make it sound as stupid as you possibly can. Please work on your curiosity.