SL Helicopter Flying Handbook

overview

1 Master Contents

Introduction to the Helicopter Aerodynamics Helicopter Flight Controls Helicopter Systems

Introduction to the Helicopter

5 Basic Flight Maneuvers

5.1 PICKUP TO HOVER

Picking up to a hover is performed by slowly raising the collective until the helicopter becomes light on the skids. Pedal should be applied to stop any rotation, and cyclic should be applied to stop any lateral or forward/back motion. Considerable left pedal may be required in the pick-up to counteract torque from the main rotor.

5.2 HOVERING

There are two types of hovering. In Ground Effect (IGE) hovering occurs in ground effect within a few meters of a surface (land, water, or a flat prim) and Out of Ground Effect (OGE) hovering occurs at altitude away from any surface. While hovering in general requires more power (collective) than other phases of flight, OGE hovering requires significantly more power than IGE hovering, and may be impossible depending on how heavily loaded the helicopter is. Cyclic inputs in a hover should be small and controlled taking into account delay between input and the reaction of the helicopter. Use collective to control hight. It is important to learn to anticipate the reaction of the helicopter in response to an input. Over-controlling is a common problem for the beginning helicopter pilot. Forward hover taxi is performed by a very slight forward positioning of the cyclic. In general all hover taxiing should be performed with no more than a dot-width of movement from the center on the cyclic control display.

5.3 SET DOWN FROM HOVER

Setting down from a hover essentially the reverse of a pickup. Slowly lower collective letting helicopter settle. As collective is lowed, right pedal may be necessary due to the reduction in torque.

5.4 NORMAL TAKEOFFS

Normal takeoffs should begin in a hover with an adequate obstacle free area ahead of the helicopter. From a hover, apply forward cyclic and allow helicopter to accelerate forward in ground effect. At about 30 mph, the helicopter will achieve ETL (Effective Translational Lift) allowing the helicopter to climb (see Section 8 for details on ETL). Some brief aft cyclic at 40 mph may be necessary. Control airspeed with forward cyclic to maintain a best climb airspeed of about 50 mph. Applying too much forward cyclic will reduce climb performance. Raise collective to increase rate of climb, but do not exceed the maximum manifold pressure of 29 inches (red line).

5.5 CRUISE

In cruise flight, use collective to control altitude, forward/back cyclic to control airspeed, and left/right cyclic for turns. Use the yaw string attached to the front of the bubble to help in coordinating turns. When the yaw string is straight up, the helicopter is aligned with the direction of movement. If the yaw string is leaning to one side, apply pedal in the direction you want it to move. For example, if the yaw string is leaning to the right, apply left pedal until it is vertical. The inclinometer (the black ball) on the HUD can be used in lieu of the yaw string. When using the inclinometer, pedal should be applied on the side to which the ball moves. Think "step on the ball". The VSI (Vertical Speed Indicator) can be used as a reference to help maintain a constant altitude. As with any helicopter, aggressive and abrupt control inputs should be avoided.

5.6 TURNS

Turns should be made primarily with the cyclic, using the yaw string to maintain coordination with the pedals as described above. In very steep turns, it may be necessary to increase collective slightly in the turn.

5.7 NORMAL LANDINGS

Begin a normal landing by reducing air speed to bout 50 mph and lowering the collective to maintain an approximately 500 foot per minute descent. Choose a target spot for your landing, keeping that spot at approximately the same place on the window. As you approach your touchdown spot, slowly decrease airspeed with back cyclic, and descent rate with up collective. Maintain above 30 mph until just before touchdown to avoid vortex ring state. As you transition to a hover, you will need additional up collective and left pedal to compensate for the torque.

5.8 AIR TAXI

An air taxi is used to move quickly from one point to another on an airport. Begin an air taxi like a normal takeoff, but lower collective slightly to maintain a height of 10 to 20 meters over the airport while pitching with cyclic for approximately 50 mph. To exit an air taxi and land, apply back cyclic, down collective and ride pedal as necessary. Then make a normal landing to hover.

6 Advanced Flight Maneuvers

6.1 MAX PERFORMANCE TAKEOFFS

If takeoff is from a confined area, the max performance takeoff procedure can be used. Begin with helicopter on the ground and collective full down. Raise collective until manifold pressure is at 29 inches (red line) while applying slight forward cyclic to begin forward movement. When clear of the obstacle apply additional forward cyclic. Once ETL is reached at about 30 mph, continue climb as normal.

6.2 STEEP APPROACHES

A steep approach can be used when landing is to a confined area. Follow the same procedure as for a normal landing, but slow to 30 mph and maintain that speed through the descent.

6.3 QUICK STOP

TBD

6.4 SHALLOW APPROACH and RUN-ON LANDING

TBD

6.5 SLOPE LANDINGS

TBD

7 Helicopter Emergencies and Hazards

7.1 PRACTICE AUTOROTATIONS

The recommended altitude for practice autorotations is 500 feet AGL. Recommended procedures are as follows:

1. Set up a stabilized constant altitude approach to the runway at 500 feet AGL, then just before crossing the runway threshold, lower collective to minimum, roll throttle to idle, and apply right pedal as necessary to maintain coordination (use yaw string for reference). Throttle can be rolled to idle by clicking on the "idle" box under the throttle slider in the HUD. The box will turn red to indicate you have enabled "idle lock" which will lock the throttle in the idle position and prevent it from coming on with further collective adjustments (disengage idle lock by clicking the box again, or clicking anywhere on the throttle slider. For a runway that starts at a sim edge, you can set up the autorotation before crossing the sim boundary.
2. Maintain a forward speed of 50-60 mph during the descent. This speed can be adjusted up or down slightly in order to land at a specific spot, but should be within this target range before entering the flare.
3. At approximately 30 to 50 feet AGL, begin a cyclic flare by pulling back on the cyclic.
4. At approximately 10 feet AGL, level the helicopter with cyclic, and begin pulling up on the collective to cushion the landing.

Timing of the flare and collective input is critical. Since throttle is locked in idle, RPM will being to decay as soon as collective is pulled. Pulling too soon will result in RPM decaying while still airborne with the helicopter dropping to the ground. Pulling too late will result in a hard landing.

7.2 PRACTICE HOVERING AUTOROTATIONS

Practice hovering autorotations from a medium height hover. The apply the following procedures:

1. Click the "idle lock" button on HUD to lock throttle in idle position.
2. Apply immediate right pedal to hold heading and maintain collective until helicopter begins to sink
3. Apply full up collective as helicopter begins to sink
4. Lower collective once helicopter is fully on the ground

The goal should be to set down softly with little or no change in direction.

7.3 VORTEX RING STATE

Vortex ring state, sometimes called "settling with power", is a dangerous condition that can occur when a helicopter is descending into its own downwash. Essentially a vortex ring system engulfs the rotors and they fail to produce lift. Once in vortex ring state, increases in power in an attempt to slow the descent will only make the condition worse, thus actually increasing the descent rate. If the condition is allowed to develop too far, or you are too close to the ground, it may be impossible to recover. You are at danger for vortex ring state when all three of the the following conditions hold:

1. Descent rate greater than 300 feet/minute
2. Airspeed less than 30 mph
3. More than 50% power

If you have alerts turned on, your helicopter will alert you when you are in vortex ring state. To recover from vortex ring state, you should lower the collective and apply forward cyclic to regain airspeed. However, the best practice is to avoid it in the first place.

7.4 RETREATING BLADE STALL

TBD

7.5 LOW ROTOR RPM and ROTOR STALL

TBD

8 Navigation

TBD