Flying Safety with Helicopters:

The helicopters are safe aerial vehicles that are produced as one or two-engined. Two-engined helicopters have been designed in order to actualize the flights in a safer environment in terms of long-term over-water flights, nights or unseeing flights (in the clouds). This does not refer to the fact that one-engined helicopters are not safe. Both one engined and two-engined helicopters have all the operations to rescue from the emergent cases and these are taught to all the pilots in all flying trainings. The helicopters are equipped with the propeller system that runs by taking its power from the engine. The propeller system of the helicopters has been produced in a manner that it continues its free cycle when engine breakdown occurs and it provides safe landing. As an important detail, the statistics shows that there has been little or no crash landing because of engine breakdown. That’s why one-engined helicopters are preferred in the cases where two-engines do not require.

Helicopter

The helicopter is an aircraft which is able to take off and land vertically aircraft with circling wings. French Paul CORNU winged the first engined-helicopter in 1907.

The helicopters can take off and land vertically and stand constantly in the air. The flying principle of helicopters and airplanes are actually the same. The airplane is moved in the air in order to obtain STALLİNG power. However, since the wing is attached to the body in the aircrafts, it is fixed. In contrast, the wings of the helicopters are not fixed but movable. Namely, circling wing that is propeller is used in helicopters in order to obtain MOVING power.

The helicopter consists of two or more propellers or blades. The profile of the propeller blade is the same as those of airplane. The engine of the helicopters spins the blades. Since the blades moves in the air, low pressure occurs at the top surface and high pressure occurs at the bottom surface of them. This pressure difference creates MOVING power. When the circling number and onset angle (the angle of the blades to meet the air) of the blades increase, the MOVING power growth increases, too. Otherwise, it decreases. When moving power equals to the weight of the helicopter, the helicopter can stand constantly in the air. When it is lower, the helicopter goes down.

When the circling level of the propeller curves, that is when the direction of moving power is changed, the helicopter moves onward-backward and to right-left sides. In this way, the helicopter is provided to move in the air. Since the propeller turns continuously (because of the moment it creates on the helicopter body), it tries to turns the helicopter body. Another small propeller is used at the tail of the helicopter in order to prevent this. The propeller at the tail damps the circling moment on the body. In addition, the circling of the body can be provided by changing the damping number.