Helicopters are capable of landing in places inaccessible to other aircraft. In addition to rooftops, mountain tops, pinnacles, and other unprepared locations, there are times when a pilot may have to operate a helicopter in areas that do not offer a solid place to land. For those operations, the normal skid gear configuration can be replaced with a set of floats for water operations or skis for winter operations.

Unlike airplanes, there is no additional rating required for helicopter float operations. However, it is strongly recommended that pilots seek instruction from a qualified instructor prior to operating a float equipped helicopter. Check the Pilot’s Operating Handbook (POH) or Rotorcraft Flight Manual (RFM) for any limitations that may apply when operating with floats installed. [Figure 9-1]

Helicopter floats are constructed of a rubberized fabric, or nylon coated with neoprene or urethane, and may be of the fixed utility or emergency pop-out type. Fixed utility floats typically consist of two floats that may have one or more individual compartments inflated with air. Fixed floats may be of the skid-on-float or the float-on-skid design. [Figure 9-2]

A skid-on-float landing gear has no rigid structure in or around the float. The float rests on the hard surface and supports the weight of the helicopter. With this type of design, be aware of differences in float pressure. While the pressures are usually low, a substantial difference can cause the helicopter to lean while on a hard surface making it more susceptible to dynamic rollover.

A float-on-skid landing gear has modified skids that support the weight of the helicopter on hard surfaces. The floats are attached to the top of the skid and only support the weight of the helicopter in water. A float with low pressure or one that is completely deflated will not cause any stability problems on a hard surface.

Emergency pop-out floats consist of two or more floats with one or more individual compartments per float, depending on the size of the helicopter. [Figure 9-3] They are often inflated with compressed nitrogen or helium and are deployed prior to an emergency landing on water. The aircraft’s maintenance manual states that the pop-out floats must be tested periodically through a deployment check, a leak check, and a hydrostatic check of the compressed gas cylinder.

To maintain the floats in good condition, perform the following tasks before and after every flight:

Helicopter floats have only a mild effect on aircraft performance, with just a slight weight penalty and reduction in cruise speed. However, the large surface area of the floats makes the helicopter very sensitive to any departure from coordinated flight. For example, in cruise flight, any yawing causes the helicopter to roll in the opposite direction, as shown in figure 9-4. A failure of the engine requires immediate pedal application to prevent an uncontrollable yaw, with a resulting roll.

Similarly, a tail rotor failure in cruise flight requires immediate entry into autorotation to prevent a yaw and the subsequent roll. Corrections to this rolling moment can exceed rotor limits and cause mast bumping or droop stop pounding.

Helicopters equipped with skids-on-floats are limited in ground operations. Minimize horizontal movement during takeoffs and landings from hard surfaces to avoid scuffing or causing other damage to the floats. Perform approaches, in which hover power may not be available, by flaring through hovering altitude in a slightly nose-high attitude to reduce forward motion. Just prior to the aft portion of the floats touching down, add sufficient collective pitch to slow the descent and stop forward motion. Rotate the cyclic forward to level the helicopter, and allow the helicopter to settle to the ground, then reduce collective pitch to the full down position. In helicopters with low inertia rotor systems, an autorotation to a hard surface requires a more aggressive flare to a near-zero groundspeed to ensure minimal movement upon landing. A running takeoff or landing on a hard surface is not recommended in helicopters equipped with skids-on-floats.