Everyone knows that where theres smoke, theres fire. When most people think about smoke and fire in aviation, three things come to mind: engine fire, electrical fire, crash site. There is, however, another form of smoke that certainly demands respect, and thats the smoke created by wildfires.
Wildfires both large and small create a number of special hazards to general aviation that must be treated with caution. Though wildfires are most common in the western U.S., urban residents of Long Island, Florida, Malibu and Oakland have experienced the powerful ravage of wildfires recently in this decade. The power of wildfire and its hazards to aviators throughout the country should not be underestimated.
When vegetation becomes tinder dry, any source of a spark (lightning, unattended campfires, discarded cigarettes, arsons) can send grass, brush and shrubs instantly up in smoke.
The leading cause of wildfire in the western United States is lightning. Between 1940 and 1975, some 79,131 lightning-ignited fires were recorded in just the forests of the Rocky Mountains. During the summer of 1988, lightning caused 998 fires in Montana alone. Even efforts to control fires can backfire, as in this springs New Mexico burn that got out of control and destroyed part of Los Alamos.
However a fire starts, its subsequent behavior depends on vegetation, climate and terrain. Dry fuels burn more readily.
Steep terrain encourages the fire to burn quickly uphill. Winds will carry pieces of burning vegetation far ahead of the flame, creating new fires and creating a hazard to everything else. Burning embers from the Sundance Fire in the Idaho Panhandle in 1967 started fires 10 to 12 miles ahead of the fire.
As a wildfire grows, hotter sections will draw in air, creating their own wind. This chimney effect then fans the flames even more, sending them shooting hundreds of feet into the air. Flames can move with frightening speed and leap over large distances. Cumulus clouds can tower up to 40,000 feet on top of smoke columns as heat and moisture from vegetation rise, producing more wind shear and lightning. The turbulence and shifting winds can be very dangerous and are best avoided by a wide berth.
Additional hazards created by large wildfires include airborne debris. Large debris is carried aloft by the updrafts and will drift downwind for significant distances. Smoke plumes are full of airborne debris that can severely damage aircraft. You really do not want to fly through a smoke plume or anywhere close to one because of the debris.
All of these hazards are sufficient for you to avoid, but if they arent enough, there are more reasons to avoid flying near wildfire incidents.
The Fight is On
No doubt youve seen news reports showing air tankers dropping red retardant on wildfires. Airborne forces are valuable resources for fire suppression because they have the capability to reach fires quickly, especially in rugged terrain. A rapid response is crucial to wildfire containment.
Federal agencies such as the U.S. Forest Service and Bureau of Land Management, state agencies such as the California Department of Forestry, and local agencies such as Los Angeles County maintain a fleet of aircraft devoted to wildfire containment. Additionally, they contract with private companies that provide specialized aircraft such as air tankers to carry retardant to hot spots.
When a fire is spotted and reported to a government firefighting agency, a regional coordinator will decide what fire fighting resources are available for dispatch. Fire fighting crews from a number of government agencies may arrive on the scene by a variety of methods. A high priority is to keep the fire from growing and spreading. Smoke jumpers form an element of the rapid attack force, and are dropped from Twin Otters, C-23 Sherpas, or DC-3s, especially in remote areas.
Other rapid attack crews may be flown in by helicopter. Ground crews will arrive by truck from whatever government agencies are responding. Hot shot crews may hike into crucial spots to slow down the fires spread. Air tankers, such as P-3s, C-130s, S-2s and some older DC-7s, sometimes guided by a lead plane such as a Beech Baron, may also be called in to fight the fire. During a big fire, dozens of helicopters from different companies from around the country will participate in the effort.
Communication and coordination in any aviation endeavor is critical, and this especially includes fire fighting. At a busy fire, pilots in spotter and lead aircraft may have to monitor as many as four or five radio frequencies. With the number of various agencies involved, you can see that communications can quickly become very complicated. The environment of smoke, heat and steep terrain only makes it worse.
The aircrews participating in fire suppression efforts may be coordinated by an orbiting lead plane that is in contact with a commander on the ground. This aircraft is usually flown by a single pilot who is busy trying to coordinate with the incident commander and ground crews. This includes flying low over the fire to determine the best entry and escape route for the air tankers, or trying to fly around the smoke to get a better view of crews or terrain. The smoke and terrain can easily hide other aircraft or abruptly rising terrain, thus increasing the hazard for a mid-air or ground collision.
Small fires that carry a potential threat to residences near urban locations or valuable natural resources such as wildlife habitat or watershed will frequently be the target of an aggressive aerial attack. Initial attack operations over rapidly evolving fires can often include one or two lead planes, air attack aircraft, sometimes one or more smoke jumper aircraft, multiple air tankers and helicopters within a fairly small segment of airspace.
In addition to the number of fire fighting aircraft, numerous other aircraft will also be around, ranging from news agencies to law enforcement to general aviation and the military. Each one increases further the risk of collision. All of these aircraft converge on a fire location from a variety of locations, times and altitudes.
Sightseeing near even a small fire can put you right in the middle of this convergence zone. This is not a safe place to be. Maintaining a safe distance from the aerial traffic over a fire incident, whether small or large, is critical to your safety.
Temporary Flight Restrictions
In order to provide a safer environment for fire fighters, the agencies involved will request the FAA to issue a Temporary Flight Restriction. The AIM states that the purpose for establishing a TFR is to protect persons or property in the air and on the surface from the hazard of low flying aircraft that would alter or magnify the hazard. The AIM also states that the purpose of the TFR is to prevent an unsafe congestion of sightseeing aircraft above the incident.
The Forest Service, Bureau of Land Management and FAA take measures to keep restrictions at a minimum while still allowing fire fighting crews a safe margin to conduct their mission. The amount of airspace may vary, but usually runs around a five nautical mile radius and to within 2,000 feet AGL from the fire activity. The actual airspace dimensions will be listed in a NOTAM. The Flight Service Station nearest the fire site normally issues the NOTAM.
NOTAMs issued for TFR areas use a specific format beginning with the phrase, Flight Restrictions followed by the affected area and effective times, area defined by altitude and radius, the coordinating FAA facility, the actual cause for the TFR, and the agency directing the effort. This standard format helps make the NOTAM easier to read and understand. NOTAMs will frequently use a nearby VOR radial and DME fix, or intersection of two VOR radials to identify the location of the fire.
Transient pilots not familiar with the names of the local VORs will find it difficult to determine if the NOTAM affects the intended flight.
While this system generally works, it isnt easy. An example of challenging airspace coordination over fire incidents was present during the 1998 fire season in Florida, where vast areas of the state were smoked in because of widespread fires during drought conditions. The congestion of air traffic over the Florida skies was due to the number of routine flights by military aircraft, general aviation pilots and commercial operations, including several large flight schools, numerous small flight and skydiving schools, airports, banner towing and the media.
This was further complicated by the arrival of a large number of disaster relief aircraft. In addition, the airspace coordinators had to plan the evacuation of airports, establish temporary control towers, help arrange international approach and departure routes, and deal with the shutdown of several major flight schools and skydiving facilities due to the TFRs.
The potential for mid-air collisions over fire incidents is a real threat, regardless of whether a TFR has been established over a fire incident. From 1992 to 1995, 56 near mid-air collisions were reported over fire incidents. Half of them required evasive action to be taken.
Thirty-five percent of the reported NMACs involved fire fighting and general aviation aircraft. The reported NMAC occurred between two fire-fighting aircraft in 41 percent of the cases, and the remaining 24 percent involved conflicts with military aircraft.
Of the 93 documented airspace intrusions into TFRs over fire incidents, 48 percent involved general aviation aircraft, 24 percent were military aircraft, 18 percent were other fire fighting aircraft, and 10 percent involved media and law enforcement aircraft. Approximately 20 percent of the TFR violations resulted in a near mid-air collision. The message should be clear by now: Flying over a fire incident is a high risk pursuit.
There are 63 airports in the western United States that function as air tanker bases. These airports have the capability to load the retardant onto the air tankers when they are instructed to load and return to a fire. Some of these airports can be fairly quiet locations until a big fire bust occurs, then it seems like chaos at the airport for several days. Locations such as Hemet, Calif., or Missoula, Mont., are active airports during the height of fire season. When wildfires begin to threaten a locality, you should anticipate a lot of air tanker traffic at nearby airports.
In the west, these locations are fairly easy to guess because airports are so far apart, and it takes an airport with a decent sized ramp and weight capability to support these larger aircraft. When wildfires threaten communities in other parts of the country, temporary air tanker bases are established. Portable mixing machines and storage tanks are trucked into the airport to provide support for the air tankers.
Temporary fire bases are frequently established at small airports to support incident command teams. Its surprising to see small county airports sometimes transformed into fire camps overnight. Ive seen airports that dont receive more than a handful of aircraft in a single week instantly transformed into a fire base, complete with a temporary air traffic control tower.
Activity at these bases can include a half-dozen or more helicopters doing external load and bucket work, resupply aircraft flying in to unload cargo, and smoke jumpers loading up for another jump. In other words, the airspace around one of these temporary fire bases can get hectic – especially to pilots accustomed to the sleepy normal operation. If a temporary air traffic control tower has been established at one of these airports to aid and control the flow of traffic, the effective dates and times will be published in the NOTAMs.
Pilots flying immediately near a wildfire are not the only ones exposed to the unique hazards. Pilots flying far from wildfires can be equally affected by wildfires as the smoke drifts far downwind. Residents of Texas endured the terrible smoke that drifted up from wildfires in Southern Mexico in 1998. In the summer of 1994, smoke from wildfires in the Idaho and Montana wilderness areas obscured visibilities through the Northern Plains for months, restricting visibility to the point that VFR conditions were marginal.
The smoke can obscure terrain and will create visual illusions far downwind. It can be bad enough to resemble flying in the dense haze of the southeastern U.S. during the summer months. The haze can be so thick that flight visibility hovers at or below IFR conditions and it becomes difficult to distinguish clouds from the haze.
Smoke, just like haze, cuts down the visibility and also reduces the color contrast, making it very difficult to see clouds or other smoke plumes. The effect of the haze seems to be worst when the sun is near the horizon in the mornings and evenings.
Shifting Fire Seasons
The fire season varies across the country, usually extending from March to October. Floridas fire season can begin in February, and with a dry spring, March, April and May can be hazardous months across the Southeast. The eastern region of the U.S. has its higher fire hazards from March through May. As early as March and April, major forest fires in New Jersey, Florida and Tennessee have required seasoned professional fire crews from the Rocky Mountain states to battle the flames.
The Southwest experiences its higher fire hazard from March through May. Texas has experienced several pronounced wildfire seasons in the last several years, sometimes beginning in March. By May, the wildfire threat shifts to the Southwest states of New Mexico and Arizona, where the wildfire threat remains high until the summer rains bring in sufficient moisture.
The lower and middle altitudes of the Central Rockies begin to dry out by June. Some of Colorados most catastrophic fires were ignited by dry lightning on July 4th in the tragic 1994 fire season.
By mid-July, the Northern Rockies and Cascades have dried out enough so that lightning storms moving in from the Pacific Northwest will ignite scores of wildfires. Lighnting storms tend to produce a large number of wildfires that put aerial fire fighting resources to work in earnest during the first few days.
The strong Santa Ana winds of Southern California are famous for drying out the hillside terrain and create some of the worst fire hazards. The steep hillsides, cramped airspace, and proximity of millions of houses makes fire suppression efforts a real nightmare. The fire season typically ends in Southern California when the rains finally move in, which usually occurs in November or December.
Since nearly one third of all the general aviation activity in the country is concentrated in Southern California, this creates a very large possibility for conflict between aerial firefighting and nearby general aviation activity. There have been unfortunate cases where aerial firefighting crews were removed from firefighting duties due to intrusions into the immediate airspace.
It doesnt really matter if a wildfire is small or large, its likely that aerial firefighting aircraft will be converging on it. The concentration of fast-paced air traffic over the fire creates the potential for mid-air collisions. For an aircraft that isnt directly involved in the suppression effort and in contact with the other aircraft, this is not a safe place to be.
Its safer to leave the area and watch the results from the evening news, which will have better pictures than youre likely to see while rubbernecking over the fire. When the heat is on, this is a very unfriendly environment for aviation and the prudent pilot really does not want to subject himself nor his aircraft to such an environment.
There is a simple way to reduce the risks involved in this environment, and that is to stay away.
-by Patrick Veillette
Patrick Veillette, a former aerial firefighter, now makes his living in the comfort of a Boeing 727.