Airport crash tender

An airport crash tender (known in some countries as an airport fire appliance) is a specialised fire engine designed for use in aircraft rescue and firefighting at aerodromes, airports, and military air bases.

Airport crash tenders are extremely powerful machines. They offer relatively good acceleration (for such large, heavy vehicles), are able to negotiate rough terrain outside the airport area, carry large capacities of water and fire fighting foam, are fitted with powerful high-capacity pumps and water/foam cannons, and are capable of delivering firefighting media over long distances. They can be mounted on 4x4, 6x6 or even 8x8 wheeled chassis. In order to decrease their turning radius, the 8x8 wheeled unit may have all 4 wheels at the front of the vehicle involved in turning the truck.

Newer airport crash tenders also incorporate twin agent nozzles/injection systems to inject a stream of Purple-K dry chemical into the AFFF foam stream "knocking-down" the fire faster. Some also have Halotron tanks with handlines for situations that require a clean agent to be utilized. These features give the airport crash tenders a capability to reach an airplane rapidly, and rapidly put out large fires with jet fuel involved.

Some tenders have an elevated extended extinguishing arm, giving a possibility to raise a water/foam cannon into the height of approx. 10 – 20 meters, that can puncture through superficial structures of an aeroplane to fight a fire inside the fuselage.

Some arms have reinforced nozzles, called a snozzle, that, according to the US National Transportation Safety Board is a "piercing nozzle on the fire truck that is used to penetrate an airplane's fuselage and dispense AFFF to extinguish fire inside the cabin or cargo area."

...
Wikipedia