You're thinking about the dead zone in the wrong way: There's a height X where you can drop the aircraft and it'll absorb all the forces to have the people live

You're thinking about the dead zone in the wrong way: There's a height X where you can drop the aircraft and it'll absorb all the forces to have the people live. There's a height Y where the parachute has enough time to deploy and bring the aircraft to terminal velocity. If X is less than Y, there's a height where there's nothing to save you. Options to resolve this are: make X higher by making the structure able to absorb more energy, or make Y lower by having it deploy faster.