Flanks : The parts of a fire's perimeter that are roughly parallel to the main direction of fire spread. The flanks usually have less fire intensity than the head fire because they have a weaker alignment with wind or slope
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}