Weather Reconnaissance Area (WRA) A WRA is airspace with defined dimensions and published by Notice to Airmen, which is established to support weather reconnaissance/research flights. Air traffic control services are not provided within WRAs. Only participating weather reconnaissance/research aircraft from...
Aero Linx: The U.S. Air Force School of Aerospace Medicine The U.S. Air Force School of Aerospace Medicine is an internationally renowned center for aerospace medical learning, consultation, aerospace medical investigations and aircrew health assessments. We promote readiness and protect...
Tetrahedron A device normally located on uncontrolled airports and used as a landing direction indicator. The small end of a tetrahedron points in the direction of landing. At controlled airports, the tetrahedron, if installed, should be disregarded because tower instructions...
Minimum Sector Altitude [ICAO] The lowest altitude which may be used under emergency conditions which will provide a minimum clearance of 300m (1,000 feet) above all obstacles located in an area contained within a sector of a circle of 46km...