| For wildfires that involve heavy fuels and high winds, flame heights can exceed 100 feet, flame temperatures |
| over 2000 degrees F and total heat output intensities greater than 10,000 BTU/Sec/FT/FT of flame front. Water, |
| when heated to evaporation from a temperature of 80 degrees F, can absorb about 9200 BTUs per gallon. In a |
| complex way it could be estimated how much water or other suppressant would have to be applied per linear |
| foot of flame front to take all the heat out of the head of a particular wildfire front (see illustration below). |
|
| Current air tankers, limited to total suppression capacities of 3000 gallons or less, are no match for the heat |
| outputs of the flame fronts of the really dangerous wind-driven fires. Other operational considerations (fire |
| generated turbulence, up- and down- drafts, smoke, etc.) also contribute to the difficulty of making direct |
| suppressant attacks on the heads of the most dangerous fires. |
|
| Serious research needs to be done to identify how much suppressant must be delivered per linear foot of flame |
| front at the head of various fires (classified by age of vegetation, wind speed, etc.) to let aircraft |
| designers know what drop capacity per unit time they must provide to extinguish the heads of the potential |
| wildfires. It is conceivable that, armed with this information, air tanker design can be evolved toward |
| design and tactics that can be successful in direct attacks on the heads of big fires. This would be a big |
| step forward from the current limitations of using the air assets only on the flanks or building retardant |
| lines out in front of the fires. |
