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| CHAPTER 9—Float and Ski Equipped Helicopters
LANDING As with takeoffs, landings in snow can prove to be extremely hazardous if reference points are not available. When possible, land near objects that won’t be easily obscured by blowing snow. If none are available, drop a marker made from a heavy object, such as a rock tied to a colored cloth; then retrieve it after landing. When the snow condition is loose or unknown, make a zero-groundspeed landing directly to the surface without pausing to hover. A shallow approach and running landing can be performed when the snow is known to be hard packed and obstacles are not hidden under the snow. The lower power required in a running landing reduces the downwash and the forward motion keeps blowing snow behind the helicopter until after surface contact. If the surface conditions are unknown, a low reconnaissance flight might be appropriate. This could be followed by a low pass. A low pass might blow away loose snow and keep the debris behind the helicopter. If the surface appears appropriate for a landing, make an approach to a high hover to blow away any remaining loose snow and begin a vertical descent to the landing. If the surface appears to be deep hard-packed snow or ice, lower the collective slowly on landing and watch for cracking in the surface. Should one skid break through the surface, a dynamic rollover is likely to follow, so be prepared to return to a hover if the surface is unstable. Skis are also very useful for landing on uneven or soft, spongy surfaces. They provide a larger surface area to support the helicopter, thus assisting in stability. Be sure that the skis are not hooked under roots or brush during lift-off. AUTOROTATION Use normal autorotation procedures in ski equipped helicopters. Perform practice autorotations on snow or sod to reduce the wear on the skis. GROUND HANDLING Shut down before loading and unloading. If shutting down is not feasible, load and unload passengers only from the front during snow and ice operations. This prevents the main rotors from striking an individual should one landing gear drop through the snow or ice. Beware of loading and unloading while running in deep snow as the rotor clearance is reduced by the height of the snow above the skids. Most skis for skid-equipped helicopters allow use of standard or slightly modified ground handling wheels. Skis for wheel-equipped helicopters often have cutouts to allow the wheels to protrude slightly below the ski for ground handling. |
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