A personal vertical take-off and landing (VTOL) aircraft is shown in Figure P6.20(a). A possible control system

Question:

A personal vertical take-off and landing (VTOL) aircraft is shown in Figure P6.20(a). A possible control system for aircraft altitude is shown in Figure P6.20(b).
(a) For K = 6, determine whether the system is stable.
(b) Determine a range of stability, if any, for K > 0.
Figure P6.20
(a) Personal VTOL aircraft.
(b) Control system.