Airtankers

The B.C. Forest Service air tanker fleet is the responsibility of the Provincial Air Tanker Centre located in Kamloops. Strategic decisions regarding numbers, position and alerts are established by the Air Tanker Centre in consultation with Air Attack Specialists and Fire Centre personnel.

The Air Tanker Centre also provides logistic support to the tanker fleet. Air crew accommodation, meals, rental cars, etc. are coordinated by the Air Tanker Centre. Services that the Air Tanker Centre provides include:

• Initial Attack on fires predicted or threatening to exceed the capabilities of ground resources
• Support Action on project fires where specific attainable objectives are in place
• Holding Action on fires where a delay in ground forces is anticipated

It is important to note that air tankers do not put out fires.

In initial attack, air tankers drop fire retardant and/or foam on or near small fires to limit their spread until ground crews arrive to extinguish them.

In support action, air tankers:

• support ground control lines (by dropping on guard lines to dampen the area)
• limit the spread on portions of the fire (controlled drops on or in front of a portion of the fire)
• cool hot spots (by drops above these identified spots to bring the temperature down)

Air tankers are usually stationed in groups of up to four aircraft, with a combined capacity of up to 15,000 litres, or over 11,000 litres for heavy single aircraft.

An Air Attack Officer flying in a smaller "bird-dog" or lead aircraft directs each group. He or she assesses the fire and directs the air tankers to the most effective and safe drop locations. The Air Attack Officer is an experienced fire specialist with knowledge of air attack techniques and ground crew strategies so that air tankers can best help the ground crews extinguish the fire.

Helicopters

Helitankers are medium-sized helicopters with a belly tank attached. These aircraft are suited for direct bombing on fires or line-building along the flanks. Helitankers can be used for long-lining (slinging from a fixed hook) without removing the tank, and other activities.

Helitankers generally have a belly tank capacity of 300 gallons. They have two doors which can be opened independently, a foam-injection system, and can be 'self-loaded' from the hover by submerging a hydraulic pump. The water source must be at least 12 inches deep, adequate rotor clearance is needed, and the tank will fully fill in approximately one minute.

Helitanker operations are coordinated by the Rapattack Duty Officer who maintains communications with fire centres and the helicopter operations technicians on board who offer the following services:

• crew delivery,
• bombing,
• off-load, and
• emergency medical assistance.

Crew delivery typically consists of deploying rappel crews, their equipment and off-loads, but can also be transporting other types of crews and equipment to fires. Passenger capacity differs with seating configuration and can range from 8 seats (rappel configuration) to 14 seats (standard passenger configuration).

When a helitanker is used for bombing, it can drop directly on hotspots or be used for line-building. Generally, water is dropped but it can be enhanced with foam if required. The tank can be filled from portable retardant tanks, lakes or other water sources with suitable rotor clearance. With trained helicopter operations technicians in the aircraft and trained crews on the ground, water reservoirs can be filled by off-loading. The helitanker can hover above a crew and drop 1-1/2-inch rubber-lined fire hose through the canopy and begin pumping (off-load) the water into the reservoir. It takes about 90 seconds to off-load 150 gallons.

Helitankers can carry an emergency medical stretcher, and with a trained helicopter operations technicians and first aid attendants on board, they can assist in provinding emergency evacuation service to injured persons in isolated areas.

Retardant

A fire retardant is any substance that by chemical or physical action, reduces flammability of combustibles. They can be dropped from an aircraft to cool a fire and slow its progress long enough for fire fighters to take action.

RETARDANTS

Water soluble retardants are most commonly used because of their long-lasting effect on fires. They contain ammonium salts which char on contact with flame. This reaction releases a water and carbon dioxide combination that cools and suffocates the fire. Fire retardants are essentially an industrial strength fertilizer with colouring.

Because the active ingredients in retardants don't evaporate, they are particularly useful in fighting high-intensity fires requiring a distant and indirect attack. In these situations, long-term retardant mixtures are usually applied ahead of the advancing fire by air tankers and helicopters.

WATER

Water is a suppressant used to suppress or extinguish wildfires. Water is applied by ground crews using water bags, tanks, pumps and hoses, or by helicopters equipped with buckets or belly tanks.

In British Columbia, aerial water bombers are usually limited to coastal areas because of adverse landing and loading conditions in many interior areas.

FOAM

Foam is a suppressant (which is similar to dish soap) that is applied to fires to suppress or extinguish them.

Fire control foam is created by mechanically aerating a water-diluted concentrate, injecting the concentrate into ground or air-borne water tanks, or by simply dropping the mixture from an air tanker or helicopter.

Once dispersed on a fire, foams absorb heat from combustion while the bubble structure slowly releases water, which is absorbed by wood fuels.

A mixture can produce dry or wet foams, depending on the ratio of water and concentrate. Dry foams produce smaller high-insulation bubbles while wet foams develop larger bubbles that provide better water penetration.

Although fire-control foams are a better suppressant than water, their usefulness is limited, particularly against high-intensity fires, where long-term retardants have proven more successful.