Flanks of a Fire 3 : The parts of a fire's spread perimeter that grow to the sides then run roughly parallel to the main direction of spread. Separated flank heads are extremely dangerous in steep terrain
Air National Guard ANG website (and US Forest Service website), Glossary of wildfire terms, Except where noted, terms are taken from: Fireline Handbook 1998, National Wildfire Coordinating Group NWCG Handbook 3 (PMS 410-1), Glossary of Wildfire Terms (additional glossary Sites included on firefighting terms and firefighting equipment), Air National Guard, The Pentagon, USA 1998. http://en.wikipedia.org/wiki/Glossary_of_wildfire_ terms, (For Fr - Amer) {2}