Apparatus and methods are provided for controlling synchronous and asynchronous communications in an avionic network. After motion estimation and motion masking for all input frames, the method enters a frame loop within which high frequency information is extracted from the input SR image for each low-resolution input image. The covering structure moves relative to the outflow opening when the stretchable element is stretched. The locking groove has a depth rod not equal to that of the unlatching groove. When the strap is tensioned a force is exerted by the strap on the floating element to force the biasing element against the bias direction. The liner also protects the user in environments where the liner is not fully effective.