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 their size and weight, 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 4×4, 6×6, or even 8×8 wheeled chassis. In order to decrease their turning radius, the 8×8 wheeled unit may have all four front wheels steerable.

Newer airport crash tenders also incorporate twin-agent nozzles/injection systems to inject a stream of Purple-K dry chemical into the AFFF firefighting 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 approximately 10 to 20 meters, that can puncture through superficial structures of an aeroplane to fight a fire inside the fuselage.

Some arms have a reinforced nozzle, called a snozzle, that, according to the United States 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.”

Tasks of the airfield fire fighting vehicle are:

Fast and massive firefighting on object areas of air traffic, even in rough terrain
Combating wildland fires outside the airport at the request of the municipal fire brigade

The International Civil Aviation Organization (ICAO) has given standards and recommended practices on rescue fire fighting categories of civil aerodromes. National aviation authorities may have given even further requirements on aerodrome rescue and fire services.

The rescue fire services are based on a critical aircraft based on a statistical analysis of movements (take-offs and landings) on the airport. The aerodrome category is based on the size of the biggest aircraft taking a movement on the aerodrome. In addition, the number of movements of the critical aircraft is calculated, and the category can be decreased by one if the number of movements is lower than the standard describes. For example, at an airport regularly handling Boeing 737 and Airbus A320 aircraft with a single Boeing 777 service per week, the airport fire service has to cater up to the ICAO category 7 of the 737 and A320; a single 777 movement per week does not justify a full ICAO category 9 fire service. There are also minimum category levels based on e.g. the number of seats in the critical aircraft.

Depending on the airport category, the standards determine the minimum number of rescue fire-fighting vehicles. In addition, requirements are given on the water and foam capacities, discharge rates for foam solutions, and minimum dry chemical powder (complementary agent) amounts, reserve stocks of fire fighting agents, ability to operate on rough terrain, and acceleration of the air crash tenders. The end of each runway has to be achieved in a response time of two minutes, and any part of the movement area has to be achieved in a response time not exceeding three minutes.

Range of airport firefighting vehicles
Airport rescue and firefighting services operate many specialist vehicles to provide emergency cover at airports. They include:

1) Crash tenders (as described above)

2) “Domestic” type fire appliances. Domestic appliances are similar in function and appearance to fire appliances operated by county fire services / departments. They are not as large or as heavy as airport crash tenders. The units are ordinarily used to respond to fire incidents in airport terminal buildings but also respond to aircraft incidents. The appliances carry Breathing Apparatus, rescue equipment, firefighting media, ladders, cutting equipment.

3) “First attack” or “rapid intervention vehicles”(RIV). RIVs are normally smaller, nimble fire appliances capable of quick acceleration and high speed. They carry less equipment than Domestic and Crash Tenders but arrive first on scene at aircraft incidents to begin rescue and firefighting operations whilst heavier / larger units approach.

4) General purpose vehicles (such as a fire chief’s car or general purpose or incident support vehicles).


FLF are not standardized. However, there are widespread types such as the Ziegler Z8, the Rosenbauer Simba or the Rosenbauer Panther, from manufacturers such as Rosenbauer, Saval-Kronenburg, Amdac Carmichael International, Gimaex-Schmitz, Simon Gloster Saro, Reynolds Boughton, Metz, E-One, Oshkosh, Sides, Magirus or Ziegler, which u. a. specialize in the construction of fire engines. In addition, z. B. also the Bremen airport In-house large vehicles.

Technical structure
FLFs are often realized in the form of large, especially heavy trucks (often also military chassis). Since the vehicles are specially designed for use on non-public areas, the specifications of the StVZO must not be observed during construction. Often, FLFs have a width of over 3 m and a total weight of considerably more than 40 t. Since air accidents can also occur off paved taxiways or runways, FLF are usually not only heavily motorized (sometimes well over 1,000 hp / 735 kW), but also remarkably off-road. Another characteristic of the FLF is its high accelerationand enormous top speed of sometimes over 140 km / h, which they can reach in part in 40 seconds. This is to be made possible despite the high total weight, a quick approach in time-critical damage situations. At major airports, these firefighting vehicles must be able to reach every point of the site within three minutes. As there are no hydrants in the area of the runways, the extinguishing agents must be carried along completely and are therefore used up quickly within minutes. Therefore, the size and weight of the vehicles also results.

The Simba in action
The loading of the FLF is very limited due to the large water and foam tank. Airfield fire engines are usually equipped with several front and roof monitors for spreading the extinguishing foam, water and powder. The operation is usually carried out by pumps (up to 10,000 liters per minute) with its own drive in order to be independent of the vehicle engine and to be able to start during the approach with the fire attack. Due to the high degree of automation (joystick control of the launcher from the cabin) often very little staff is required. Newer vehicles are also equipped with telescopic extinguishing arms (HRET), some with aFire lance penetrate through the outer skin of the aircraft and can also fight fires inside the aircraft. In individual cases, lighting equipment, hydraulic rescue equipment, ladders or small quantities of other extinguishing agents (nitrogen) are carried along.

For civil aviation: In the early days military aviation was the pacemaker for the development of aircraft fire protection. Even before the First World War, the first special fire-fighting equipment to secure flight operations was procured on the airfield and sports field Berlin-Johannisthal. The first real engine splashes were then acquired during the World War. However, these differed little from the usual of the time. 1927 was in Wroclawa first special vehicle, a so-called disarming vehicle, procured. In the period since 1933, safety requirements for the airfields were laid down for the first time and special aerospace guns with very extensive foam equipment were created. The Air Force was now the leading force and introduced the widely used 2.5 fuel tank, which was equipped with 2,500 liters of water and 300 liters of foam and formed the backbone of the aircraft fire protection throughout the war.

After the war, civilian flight operations returned only slowly. At the airports mostly the old equipment was used after the necessary repair. In the 1950s and 1960s, the operators procured the first new vehicles, mostly FLF 25 and feeder vehicles ZB 6/24. With regard to the entrained extinguishing agents, the new ones usually corresponded to the old aircraft tankers, but were continuously provided with a closed body and water cannons on the roof. During this time, the runway foaming came as a means of emergency landings and special foam trailers were ordered. Finally, the first pure powder or dry-fire vehicles with up to 2,000 kg of extinguishing agent found their way to the airports.

In the early 1970s, with the introduction of the Boeing 747 jumbo jets, a new era in aircraft fire protection began. Higher regulatory safety requirements made completely new vehicles necessary. This led to a gigantism, which was particularly noticeable at Frankfurt am Main and Munich airports. For example, superstructures with up to 18,000 liters of water plus 2,000 liters of foam were fitted on four-axle Faun special chassis from various manufacturers. Dry-fire vehicles achieved extinguishing agent quantities of up to 12,000 kg of powder.

In the early 1980s, however, it had been recognized that the giant giant were too cumbersome. To comply with the legal requirements for the intervention times, therefore initially small RIVs (Rapid Intervention Vehicles) with high engine power and moderate extinguishing agent loading were procured. However, the airports began back in the late 1980s to order larger FLF again. This generation still today carries up to 15 tons of different extinguishing agents with an engine performance that surpasses that of the fire-fighting giants from the 1970s. End-of-life vehicles are usually reused on smaller airfields or sold abroad.

In the GDR, after the war, as in the West, old vehicles were first used. From the mid-1950s TLF 15/53 on the Horch G5 chassis of domestic production were also put into service for airports. When taking up international flight operations, however, it became clear that the GDR vehicles did not meet the requirements. Therefore FLF 25 was imported from Germany. From the end of the 1960s came then TLF 32 on the Czechoslovak chassis Tatra 138 and 148 later on. The Karosa construction summed up 6,000 liters of water and 600 liters of foaming agent. In the mid-1980s, these were replaced by Tatra 815detached with Karosa structure (8,200 liters of water, 800 liters of foaming agent). But even these vehicles did not meet the technical standard in the West, for example, because the only launcher on the roof still had to be operated manually, the foam pump was too small and the maximum speed compared to low.

The level of fire protection for airfields is subject to a number of specific requirements. They are primarily conditioned by the need to save people in the event of aircraft accidents and to extinguish fires on them. At aerodromes there is a need to extinguish burning spilled fuel both under the fuselages of aircraft, and on the runway (runway), and even outside it. Sometimes there is a need to cover the runway with a layer of air-mechanical foam to facilitate the landing of aircraft in distress.

Reducing the likelihood of fire when landing on a runway, covered with foam, is due to the following factors:

reduction in the degree of damage to the structure of the aircraft due to the reduction of the braking forces when it slips along the foam, which reduces the probability of destruction of the aircraft systems and the occurrence of a fire;
decrease in the probability of ignition of aviation fuel due to a decrease in the concentration of its vapors in the air due to the insulating properties of the foam layer;
the spark-out effect in the foam.

In addition, during the emergency landing of the aircraft on the foam strip due to the insulating action of the foam, the intensity of a possible post-emergency fire decreases.

The main purpose of airfield fire trucks is to save people in the event of an airplane crash. The fuel spills resulting from a catastrophe lead to the emergence of a rapidly spreading flame front, which affects the hull of the aircraft. Studies show that with a good thermal insulation between the outer lining and the lining of the cabin, the period during which the life of passengers can be saved is an average of 3 minutes (but not more than 5 minutes). The need for rapid delivery to the place of flight incident of extinguishing forces and means requires the use of heavy-duty high-speed chassis for aerodrome vehicles. In addition, the distinctive features of airfield fire trucks are their high dynamic qualities, cross-country ability in off-road conditions,

By designation, firefighters of airfield cars are divided into starting and main.

Starters are in the immediate vicinity of the starting runway. In addition to the usual PTV configuration, which is typical for any main general – purpose fire truck, starting cars additionally take out a special tool and equipment necessary for carrying out emergency rescue operations and extinguishing fires on aircraft.

The main fire trucks are located in the fire department and leave on alarm.

Source from Wikipedia