An aircraft seat has an adjustable armrest in which the armrest platform is supported by a hinged attachment to an armrest support member. The hinged attachment between the armrest platform and the arm support member is located at the wrist-end of the arm support member near the aircraft control stick. The armrest platform and the armrest support are locked into position by means of telescoping struts that are controlled at the wrist-end of the arm platform member. The telescoping struts can be selectively locked to create triangular and/or quadrilateral trusses that lock the armrest firmly into position and may include springs or other elements to bias the armrest platform up and forward so that the armrest “floats” when the telescoping struts re released.