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how to fly a helicopter

A helicopter creates lift in a different way. Where a fixed wing aircraft has to be moving to produce lift by the "plane" or angle of attack on the wing, a helicopter achieves it by manipulating the main rotor blades, changing the angle at which they meet the air and subsequently the angle of attack. The drawback with this setup is the need for torque control with a tail rotor, which bleeds power from the engine every time it's used. That becomes a factor when you start getting into advanced manoeuvres.

Terms

The collective control is the lever to the left of your seat mounted on the cabin floor. Moving the collective up or down is what creates pitch change in the rotor blades, causing you to climb or descend.

You must use one hand on the control lever that is at your side (the collective control stick) to raise or lower the helicopter, while at the same time controlling the throttle (not an easy task).
This is a control which is only found in helicopters and is linked to the engine power. Moving this up and down changes the pitch of the main rotors. As the pitch is increased more power is required from the engines so that the rotor speed is kept at the same level.

The cyclic control is the actual "stick." It tilts the main rotor assembly through 360 degrees, allowing forward, backward and sideways flight.

You must use your other hand on the control lever that is just in front of you (the cyclic control stick) to move the helicopter forward, backward and to either side, as if you were in a conventional aircraft.
Moving it forward or back will point the nose of the helicopter up or down. It does this by varying the angle of the rotor blades as they go round, tilting the rotor back and forth. When moved left or right the rotor tilts in that direction and the helicopter banks and rolls.

And finally you must use the tail rotor pedals, on the floor, to control the pitch of the tail-rotor. For straight flight, the pitch of the tail rotor is set to prevent the helicopter from turning to the right as the main rotor turns to the left. The pilot pushes the left pedal to increase the pitch of the tail rotor and turn to the left. Pushing the right pedal decreases the pitch of the tail rotor and turns the helicopter to the right.

The throttle control is a 'twist-grip' on the end of the collective lever and is linked directly to the movement of the lever so that engine RPM is always correct at any given collective setting. The pilot only needs to 'fine tune' the throttle settings when necessary.

Airspeed

Controlled with pitch - While maintaining altitude, move the cyclic to change the airspeed. This requires a little coordination, similar to the throttle and yoke in a fixed wing. In level flight you increase collective/move the cyclic forward to speed up, reduce collective/pull the cyclic back to slow down. As you approach your desired speed, you have to adjust the collective to maintain it. It's a good idea to practice since you'll do this every time you take off or land.

Altitude

Controlled with power - Pull the collective up to increase climb rate, lower it to increase descent rate. This is combined with cyclic movements to produce constant speed climbs and descents or level flight. While at cruise altitude and power, any minor altitude adjustments can be made with the cyclic only.

Behaviour

Helicopters are highly sensitive to input and very responsive. Slight pressures are required to master the finer techniques in hovering and landing.

Most helicopters have no form of adjustable trim. For example, if you pitch down when levelling off from a climb, the aircraft will continue descending unless you make an opposite cyclic input from the neutral position. Once you've levelled out, you need another input to take out that correction. This characteristic applies to forward, backward and sideways flight, and on a smaller scale in a hover.

Performance in any "mode" will be more responsive to input. Whereas a fixed wing may become sluggish and hard to control at slow airspeeds a chopper stays just as responsive if not more so.

Power reductions require some attention. The main rotor blades are your only means of creating lift, so if you drop the collective completely there's nothing holding you up, even though the throttle is wide open. All helicopter pilots are taught to "glide" the helicopter with little or no power to the ground. A little known fact (much like those seeds that fall off trees- "twirlybirds" I think kids call them) is that a helicopter will still "fly" or glide by the simple fact that the blades will spin on the way down. The landing may be hard but as you will see not impossible.

Winds and turbulence play a large role in how you control and master the dynamics. Much as a fixed wing takes off in the direction of wind so too should your chopper.

One of the things that remain constant in fixed and non-fixed wing aircraft is that in a turn you loose altitude and go nose down without correction. This doesn't apply to "side" stepping in a hover.

Takeoff

A normal takeoff is performed in the following fashion. First, you must make sure the throttle is all the way open (For a turbine powered helicopter, advanced properly for a reciprocating engine powered helicopter).  Once you have established the proper operating RPM, then you can pull up slowly on the collective. As you increase collective pitch, you need to push the left pedal (In American helicopters...right pedal for non-American models) to counteract the torque you generate by increasing pitch. (In reciprocating engined models, you will advance the throttle as you increase collective pitch). Keep pulling in pitch and depressing the pedal until the aircraft gets light on the skids. You may sense a turning motion to the left or right, if so, you may need more or less pedal to maintain heading.

The cyclic will become sensitive and (depending on how the aircraft leaves the ground heels or toes of the skids last) as you continue to pull in pitch and depress the pedal, you will put in the appropriate cyclic input to level the aircraft as it leaves the ground. As the aircraft eases into the air, forward cyclic will be required to start the aircraft in a forward motion. As the aircraft advances forward, it will gain speed until about 15 knots and then the aircraft will shudder a little as you transition through ETL (Effective Translational Lift...See the unique forces page for a more in depth explanation of ETL). As you transition through ETL, the collective will need to be reduced, the pedal will need less pressure, and the cyclic will need to be forced forward to counteract the force against the front of the rotor system.

Failure to push forward will result in an abrupt nose high attitude and a reduction in forward speed. After the shudder of ELT is experienced, you will see a marked gain in forward airspeed, a reduced need for pedal input and a reduced need for collective pitch as the rotor system becomes more efficient. The airspeed indicator will most likely jump from zero to 40 knots indicated airspeed and will smoothly advance as the aircraft goes faster. Now you have taken off and with a little release of forward cyclic pressure, the aircraft will establish a climb and continue to gain airspeed. At this point, the pedals are only used to trim the aircraft, and most manoeuvres are accomplished by using a combination of the cyclic and collective controls.

Gently

The largest error made by new chopper pilots is to "over-control". That means making control movements that are out of proportion to the corrections required. It's common in the beginning and keeping corrections small but immediate is important. Cyclic and tail rotor movements affect each other and precision is impossible if you're heavy-handed. So before adding collective, the cyclic should be in the neutral position. Otherwise you'll start moving the second you leave the ground. If you lift off with things centred you can devote more attention to heading and drift. You're less likely to have to make big hazardous corrections.

Climbs and descents

Over airports and flat ground you won't go wrong using the numbers in the pilot operating hand book. Climbs and descents over rough terrain generally don't work with those speeds - out of necessity they tend to be slower, and climbs tend to be steeper. There are a few things to watch in a steep climb. Try to maintain at least 15-20 knots indicated airspeed. Depending on the altitude, slowing to zero in a climb can result in an unplanned descent, and below 20 knots speed bleeds off quickly. Add collective carefully and don't exceed the limit of the yellow "max continuous power" range on the torque gauge.

Hovering

A big selling point of helicopters is that you can land in your backyard. Where then would be the best place to learn to hover? An airport with a 12,000' runway and a 7,500' crosswind runway. You want a lot of open space where you're guaranteed not to hit anything. You want somewhere that neighbours won't complain about the noise. You want somewhere with long sight lines to the horizon so that you won't concentrate your gaze in too close. You want somewhere that you can get fuel when you run out. All roads lead to the big airport! Generally the tower and ground controllers will give you permission to practice hovering on whichever runway isn't be used that day and/or over a seldom-used taxiway.

Most instructors will start by giving you one control at a time. You take the antitorque pedals and they handle the cyclic and collective pitch. You practice pedal turns. Then you take the collective while the instructor controls the cyclic and pedals. You go up, you go down. Maybe you land. Then you take the cyclic and the instructor takes the other controls and ... 1 second later the helicopter is oscillating like crazy and you hear "I have the controls" in your headset. Any good instructor will alert you to the fact that you need to be very light on the controls: "you fly with pressures, not movements." The instructor will also tell you that there is a bit of lag between the time that you put in a control input and the time that the helicopter reacts. What most instructors won't tell you is how to deal with these facts.

Here are a few tips for handling the cyclic, which controls forward/back and left/right movement of the helicopter:

  Focus your gaze at least 1/2 mile in the distance if the sightlines in your practice area are long enough.

  As soon as the helicopter is handed to you it will start to drift to the right. The tail rotor is counterbalancing engine torque but at the same time is pushing the machine to the right. Expect to hold a little bit of left pressure on the cyclic to avoid this translational drift.

  Don't put in and hold a control input pressure. Suppose the helicopter is moving forward a bit. You press back on the cyclic and hold that pressure. One second later the helicopter has responded to the initial pressure by arresting its forward creep. One second after that the helicopter has responded to two seconds of continuous pressure by rushing backwards at a frightening clip. If the helo is moving forward, press backwards for a split-second then try to return the cyclic to a neutral position. See if the helicopter stops creeping. If so, great. If not, try another little stab of back pressure. Although every second or two you are doing something with the cyclic, in any given instant you need not be putting in any cyclic input. Nudge the cyclic and then return to centre. Nudge and then return.

  After an hour or two the instructor might be doing more harm than good in handling the other two controls. Everything is cross-coupled so if he is messing with the collective or the pedals it will require you to take action with the cyclic. It is actually easier to handle all three controls because at least the machine isn't doing completely unpredictable things from your point of view.

  Take a break every 20 minutes by practicing takeoffs, trips around the pattern, and approaches to landings.

Approaches

One of the keys to a good approach is maintaining visual contact with your landing area. It's impossible to adjust your descent rate correctly if you lose sight of it. Sometimes this means turning the nose slightly with the tail rotor to keep things in view. That comes with practice. Think of the approach as you might in a fixed wing by imagining a glideslope and a touch point that you want to arrive at.

Landing

 
 Plan on being at about 200-500ft. above ground or obstacles .5km from the landing area. Try to gauge your rate of descent by a reference on the ground. If you reach this target altitude early, hold it until you reach about .2km from the landing area. With your first couple of tries remember to keep an eye on your airspeed. it's very common for pilot in training to overshoot the landing area.

   Slow to 40 knots 35-37% at about .2km from the landing area and begin to slowly descend. Things will start to happen fast. Check your descent rate. It's very important that you don't let your vertical speed get past 300' per minute - adjust power as required. Obstacles permitting, you want to be roughly as high above ground as the width of the rotor blades when you arrive at the edge of the landing area. As you get closer and closer to the edge, gradually slow to 30, then 20. You may loose sight of the landing area briefly while bringing the nose up to bleed off some of that airspeed. Whether you're descending or not while doing this, you'll still have to carefully coordinate pitch and power. Next to hovering, that's probably the biggest challenge of the approach. I

   As you cross the edge of the landing area, you should be levelling off and continuing to slow below 10 knots. You may have to reduce power slightly and bring the nose up to do that. Watch the ground to ensure you remain moving forward as you drift into position. When the exact spot you want to land on appears to slide beneath the nose, you'll be in a good position to reduce collective. Make sure your parking brake is armed.

   Ease the cyclic back to bleed off any remaining momentum, then ease it forward again to level the attitude indicator when all forward movement stops. At the same time if the rate of descent is too much add some collective. Now it's just a matter of keeping an eye on drift and getting the wheels to make contact with the ground. Keep your rate of descent as low as possible. Have the Parking brake armed and reduce all power.
 

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