Abstract: A mooring and landing device for aircraft which are capable of vertical dent for landing comprising an inflatable tube-type device, or trunk, attached to the bottom surface of the craft. The trunk is in the shape of a doughnut and the open interior compartment formed by the inflated trunk and the bottom surface of the craft is evacuated to a pressure lower than atmospheric so that the difference between the compartment pressure and the atmospheric pressure moors the craft to the ground. The trunk is inflated to a pressure greater than atmospheric and may be formed with a plurality of holes to provide an air cushion for lubrication purposes.

Abstract: A miniature waveguide attenuator which may be used in a dominant-mode (TEb.10) waveguide to maintain a low VSWR over a 20% frequency band comprising a short section of waveguide with an E- or an H-plane tee whose width is selected to set the cutoff frequency of the branch line of the tee at the design frequency F.sub.o. The branch line of the tee is terminated in a lossy material followed by a short circuit for absorbing energy propagating down the waveguide at frequencies higher than the design frequency in accordance with a controlled attenuation characteristic.