Change should be in the air.
"The thing is helicopters are different from planes. An airplane by its nature wants to fly, and if not interfered with too strongly by unusual events or by a deliberately incompetent pilot, it will fly. A helicopter does not want to fly. It is maintained in the air by a variety of forces and controls working in opposition to each other, and if there is any disturbance in this delicate balance, the helicopter stops flying'immediately and disastrously." 'Harry Reasoner, 60 Minutes.
Heightman
A J
AJ
D017732:Air Ambulances / Q000458:organization & administration*; D014481:United States