Helicopter 6 : An aircraft capable of hovering and moving vertically and horizontally in any direction during flight. Most helicopters achieve lift and propulsion through the rotation of overhead rotor blades.
Dr. Robert Stacey (compilor), European Glossary of Wildfire Terminology (Covering areas of wildfire environment, fire behaviour, fuel, topography, weather, wildfire suppression operations, safety, incident command, tactics, cartography and map reading, equipment, aerial operations, wildfire preparation, prevention and recovery, prevention and detection, fire investigation and restoration), EUFOFINET (European Forest Fire Networks) Project, Northumberland Fire and Rescue Service, Northumberland UK 2012 (1st Ed.). http://www.fire.uni-freiburg.de/literature/EUFOFIN ET-Fire-Glossary.pdf, (For Fr - Brit) {808}