"The thing is, helicopters are different from planes. An airplane by its very 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. There is no such thing as a gliding helicopter."
"This is why being a helicopter pilot is so different from being an airplane pilot, and why in generality, airplane pilots are open, clear-eyed, buoyant extroverts, and helicopter pilots are brooding introspective anticipators of trouble. They know if something bad has not happened it is about to!" :)