A Successful Helicopter Auto Rotation Could Save Your Life

An auto rotation is an emergency procedure that every helicopter pilot will have to practice during their training. To pass remortgage helicopter flight test you will need to be proficient with this maneuver and show that you have industrial injury ability to complete it with skill and competence.

Why do we need to know how to auto rotate?

If a helicopter engine should fail, we need to be able to maintain the speed of the main rotor system. If we don't, the resulting loss of lift will cause the helicopter to fall to the ground. A successful auto rotation could save your life.

A helicopters main transmission is connected to the engine via a free wheeling unit or sprag clutch. In the event of an engine failure, the transmission and rotor system is free to rotate. Think of riding a bicycle, when you stop peddling the rear wheel is free to rotate without the pedals moving.

We can maintain the speed of the main rotor system by reducing the pitch of the main rotor blades with the collective lever, which creates less drag. To picture this, imagine you are driving a car with your arm stretched out of the window with the palm of your hand parallel to the surface. You will notice that your hand slips through the air with little resistance. If you twist your palm to about forty five degrees to the surface you will feel more resistance.

During auto rotation, the main rotor system is being turned only by the upward flow of air as the helicopter descends. This is similar to a sycamore leaf rotating as it falls through the air.

Helicopter main rotor systems are designed to operate at a certain speed with a small amount of blade coning. Coning is the angle at which the rotor blades flex upward as load is increased. If the rotor blades are allowed to move upward too much the rotor system will try to over speed. Imagine an ice skater spinning on the ice with arms out stretched, now they fold their arms up over their head and they begin to speed up rapidly.

Care should be taken not to let the rotor rpm get too high or too low. Fly the helicopter as normal, with smooth, gentle inputs. If the rpm gets too high, raise the collective lever a small amount, if it gets too term insurance quotes online you can turn the helicopter or ease back on the cyclic to load the rotor system.

After a helicopter engine fails or is deliberately moved to the idle position for practice auto rotation, the helicopter will yaw left or right depending on the type of helicopter.

You will need to apply left or right yaw pedals to keep the helicopter in trim (not flying sideways). This is due to the loss of torque after the engine fails.

American helicopters have rotor systems that rotate counter clockwise and European helicopters rotate clockwise. This will determine which pedal we use to keep the helicopter in trim.

Most helicopters descend at approximately 1500 - 2000ft per minute during auto rotation, but this varies with type of helicopter, weather conditions, weight and other factors.

While maintaining the rotor rpm with collective, controlling our speed with the cyclic and keeping the helicopter in trim with the yaw pedals we should approach the surface with approximately sixty knots of air speed. Upon reaching approximately fifty feet above the ground we begin to flare the helicopter by using aft cyclic to reduce our rate of descent and slow our forward speed. At this point the rotor rpm will begin to rise due to the increase in load on the rotor system. Raise the collective a small amount midphase web hosting the desired rpm is attained and lower back down again.

As the helicopter continues to descend, level the aircraft with forward cyclic and raise collective lever to cushion the landing with the remaining rotor rpm. Ideally we would like to touch down with zero forward speed, but some speed will help with cushioning the landing. If you touch down with forward speed keep the landing gear straight and parallel with your direction of travel to prevent the helicopter from rolling over.

Some common mistakes made during practice auto rotation.

1.Failure to maintain correct air speed.

2.Failure to maintain rotor rpm.

3.Failure to focus attention outside of cockpit.

4.Failure to keep helicopter straight and level on touch down.

5.Poor timing of cyclic flare.

6.Poor timing of cushioning touch down.

7.Being tense and over controlling.

An auto rotation is probably one of the most difficult helicopter maneuvers to master. There is so much to think about in a short space of time that it can be overwhelming for the beginner.

Your introduction to an auto rotation should be carried out with you following through on the controls with your instructor. The entry should be smooth and slow so as not to scare you. Some instructors have a bad habit of slamming the collective on the floor causing you to rise up out of your seat and hitting your head on the ceiling. It should be practiced over a safe area away from people and property. Preferably over a runway at an airport in case the engine really fails.

Once the helicopter is established in a descent the helicopter is easily controllable and very maneuverable. Only small, smooth control inputs are required to fly the helicopter to the ground.

If your engine fails, you only get one chance to get it right. Practice as much as possible until it becomes instinctive.

Visit helipilotcareers.comhelipilotcareers.com for more information on helicopter safety and starting a career as a commercial helicopter pilot.