US Patent 11021227 Access cover

An access cover for an aircraft hole that comprises a plurality of access cover holes, an inner surface, a plurality of first projections protruding from the inner surface, and a plurality of fixing elements configured to fix the access cover to a supporting structure of the aircraft hole. The fixing elements each comprise a male fixing element having an outer threaded surface, the male fixing element being configured to pass through a hole, and a locking element comprising a threaded hole and an extended portion, wherein the outer threaded surface of the male fixing element is configured to thread with the threaded hole of the locking element.