Ch 09.qxd 8/25/04 11:32 AM Page 9-5 horizontal movement. This procedure is similar to landing on a hard surface. Make a running landing on water when high density altitude or a heavy load results in insufficient power to hover. Perform this type of landing when sufficient power is not available to reduce the speed to 5 knots or less. When approaching with greater than 5 knots of speed, hold a slight nose-high attitude to allow the aft portion of the floats to plane. Maintain collective pitch until the speed reduces to below 5 knots, and the heli- copter settles into the water. At zero groundspeed, slowly lower the collective into the full down position. Lowering the collective or leveling the helicopter too quickly may result in the floats tucking, which can cause the helicopter to capsize. Landing the float helicopter becomes  risky when the height of short, choppy waves exceed one half the distance from the water to the helicopter’s stinger, and the distance from crest to crest is nearly equal to or less than the length of the helicopter. These waves cause the helicopter to pitch rapidly and may bring the rotor blades in contact with the tail boom or the tail rotor in contact with the water. In addition, avoid landing parallel to steep swells as this could lead to dynamic rollover. [Figure 9-5]  If landing on waves higher than half the distance from water to stinger, the following techniques apply: ¥ Land the heading into the swell. This minimizes the fore and aft pitching of the fuselage, reducing the possibility of the main rotor striking the tail boom, or the tail rotor contacting the water. This also minimizes the possibility of dynamic rollover.  Figure 9-5. Effect of landing heading relative to waves. 9-5 Perpendicular to Swell Parallel to Swell Angled 30¡ to 45¡ to Swell Rotor Strikes Tail Boom Dynamic Rollover Tail Rotor  Strikes Water Caution: The following discussion deals with land- ing in heavy seas. Use these procedures only in an emergency.