Abstract: An aircraft landing gear system including a window shaped type membrane wh is mechanically stretched prior to landing. The large surface area of the membrane would significantly increase the load bearing area of the helicopter, enabling landing in snow. Upon takeoff, the member would be rolled up.

Abstract: An underwater frazil ice detector is disclosed comprising channel means disposed underwater for moving water therethrough, means for drawing water through said channel means, screen means disposed in and across said channel means so that water drawn therethrough by said water drawing means passes through said screen means, pressure detecting means disposed in said channel means and downstream of said screen means for detecting pressure differential across said screen means, whereby flow of water through said screen means is constricted when frazil ice forms thereon, creating an increased pressure differential across said screen means and thereby indicating the presence of frazil ice.

Abstract: A liquid sampler, and particularly, a liquid sampler for sampling liquid taining frazil ice, employs a sampling tube open at both top and bottom which can be thrust into the liquid to be sampled and a membrane-type cylindrical valve which is closed by pulling a single string which is looped about the cylindrical membrane. A cutting shoe at the lower end of the sampling tube permits cutting through ice for obtaining the sample.