| With few exceptions, the airborne assets currently used to fight wildfires are not equipped or trained to fight the |
| fires at night. Because of this, for almost 50 percent of the clock time, the fires are allowed to burn unchecked |
| by any efforts from the aerial assets! |
| This is unfortunate because during the night, winds often subside or change directions such that the fires are |
| more amenable to aerial suppression. The technology to fly effectively close to the ground at night has been |
| perfected by the military and is now available to be translated to civilian uses. By adding night capability, the |
| availability of current aerial assets can be almost doubled without adding any more aircraft. |
| The illustration shows, for California conditions, how the lack of night capability reduces the availability of the |
| aerial fleet to fight fires over the course of an incident. |
| The illustration also shows how the lack of night capability combines with the inability to operate effectively |
| when wind speed exceeds about 35 mph to typically reduce the availability of aerial assets to only 25% of daily |
| clock time during the critical fall wildfire events in California. Similar situations occur in other states as well. |
| A current rule of thumb sends most of the airborne firefighting fleet home when surface winds move into the 35 |
| mph range. These high steady surface winds are accompanied by transient gusts that can add or subtract from |
| the local steady speeds. If large enough, these gusts can momentarily subtract from the effective airspeed |
| needed to keep the aircraft flying at a selected altitude and cause a serious safety problem. The unpredictability |
| of the gusts tends to spoil the aim of the drops. The higher wind speeds can also contribute to earlier breakup or |
| evaporation of the drops before they reach the fire. These adverse effects can be reduced by use of aircraft |
| designed to fly safely at very low airspeeds or by employing new technologies to deliver the fire suppressant |
| (retardant, gel, foam, water,...) without breakup until it reaches the proper altitude above the fire. |
| The current fixed wing air tankers, with few exceptions, do not have sufficient low speed capability to make |
| effective drops when local steady wind speeds exceed 35 mph. Their drop systems also contribute to reduced |
| effectiveness if loads must be released at altitudes more than a few hundred feet above the fire. During really |
| dangerous wildfires, these strong winds are present during about half of the daylight hours and thus, the aircraft |
| are also unavailable for another 25% of the available clock time, as seen in the illustration above. |
| Potential technology improvements to reduce or eliminate these problems have made little progress because |
| they involve significant expense and, so far, the firefighting agencies have no budgets to address these |
| problems. They rely on private ventures (who must proceed with no assurance of cost recovery or follow-on |
| profitable provisions of products or services) to introduce the needed changes. Decision makers need more |
| information for the confidence level required to proceed with projects that can resolve these problems, |
| i.e., we need more basic and applied research in this area. The illustration below shows the general form of |
| the information that needs to be collected and made available on a regular basis to the firefighting services. |
| Ultimately, we need aircraft capable of effective use during higher wind conditions and/or systems that will |
| allow suppression mediums to be delivered by aircraft without the loss of effectiveness currently experienced |
| in high winds. One such concept is currently in development by a private venture called Precision Container |
| Air Delivery System (PCADS) which drops disposable containers of suppressant out the back of rear loading |
| ramp transport aircraft that open at significant distances below the aircraft before dispensing into the fire. |
| See figure below. |
| This technology can probably be further developed to allow water or other suppression medium to be dropped at |
| higher altitudes and speeds in a way that will preclude premature blooming and disintegration and also arrive at a |
| previously designated spot regardless of gusts and turbulence. The system would keep the suppression medium |
| protected from dispersal until it reaches an optimum altitude and speed relative to the fire for maximum |
| suppression effect. See figure below. |
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