|CHAPTER 9—Float and Ski Equipped Helicopters
CONSTRUCTION AND MAINTENANCE REQUIREMENTS
Helicopter skis are made from plastics and composite materials such as fiberglass with steel and aluminum hardware. Steel runners on the bottoms of the skis protect them during hard surface operations. Excessive wear of these runners can lead to wear or damage to the skis.
All of the steel bands securing the skis to the skids should have a protective rubber lining preventing the bands from wearing into the skids. This lining should be replaced if it becomes brittle or shows signs of wear.
Have any damage to the skis repaired before flight even if the skis are not needed, or simply have the skis removed. A cracked ski could break off and damage the helicopter or injure people on the ground.
Apart from the small weight penalty and slight reduction in speed, a ski equipped helicopter operates exactly like one with no skis. The main concern when operating with skis is to avoid operations that may damage the skis, such as landing on rocks or rough hard surfaces.
The preflight inspection consists of the standard aircraft inspection and includes additional items associated with the skis. The POH or RFM contains the appropriate supplements and additional inspection criteria. Typical inspection criteria include:
Helicopter starting procedures on snow and ice are identical to a hard surface starting procedure except that care must be taken to maintain antitorque control on a slippery surface. When performing the free-wheeling unit check on ice, place the pedals in the autorotation position to prevent the helicopter from spinning.
TAXIING AND HOVERING
When hovering over snow, the rotorwash may create a white-out condition if sufficient loose snow is present. Blowing and drifting snow may give the illusion of movement in the opposite direction. When operating in snow, it is vital to select a reference point to maintain situational awareness and take off directly to a high hover at an altitude that allows visual contact to be maintained. When performing a hover taxi, select the speed just above effective translational lift to help keep the blowing snow behind the helicopter. If loose snow is less than 6 inches, it may be possible to apply collective pitch to create enough rotorwash to blow away the majority of the snow before lift-off. If moving the helicopter a short distance, and especially when around other aircraft, it might be preferable to surface taxi on the skis.
When taxiing wheel-equipped helicopters on snow and ice, use caution when applying the brakes. If the helicopter begins to skid sideways, lower the collective, which places all of the weight on the wheels and move the cyclic in the opposite direction of the skid. If the skid continues, the best option at that point is to bring the helicopter into a hover, but be aware of objects that could lead to a dynamic rollover situation.
Normal takeoff procedures are used in snow and ice, but before startup, check the departure path for any obstructions that may be obscured by blowing snow. Powerlines are difficult to see in the best conditions and nearly impossible to recognize through blowing snow.
Perform a takeoff from a hover or from the surface by fairly quickly increasing speed through effective translational lift and gaining altitude in order to fly out of the low visibility conditions. A takeoff from ice requires slow application of power and proper pedal application to prevent spinning. At certain temperatures, the skis may freeze to ice surfaces. If this occurs, a slight left and right yawing with the pedals may break the helicopter free. If this does not free the skids, shut down the helicopter and free them manually. Excessive pedal application could damage the skids.
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