Description

This article relates to vehicles employed on the manouevring area of controlled aerodromes (airside).

Vehicles are an integral part of aerodrome operations. Depending on their individual function they vary in size and shape and are used for various reasons, such as guiding aircraft (follow-me), performing runway inspections, providing emergency services, snow removal, construction works, aircraft fueling, towing, passenger and baggage transport, security, police or other airfield operation.

Effects

A safe operation of airside vehicles is crucial to ensure and maintain surface safety at an aerodrome - especially on its aprons, taxiways and runways. Given the dynamic and sometimes complex environment in which ground vehicles are operating certain risk and safety consideration are necessary to prevent the occurrence of safety events such as runway incursions, near misses and collisions between vehicles, between vehicles and persons, or between vehicles and aircraft. 

Areas of operation

One of the most well-known airside vehicles used on aerodromes is the ‘Follow-Me’ vehicle due to its often prominent yellow-black checkerboard painted look. In many cases it is not only used for guiding aircraft into or from their parking positions, but additionally also for runway or airfield inspection and oversight purposes so that their presence is common on all areas of an aerodrome.

Some vehicles with specific functions such as tow trucks, baggage carts, mobile stairs or fuel trucks are most often only operated on aerodrome aprons while the operation of other vehicles such as snow removal and de-icing equipment or emergency service cars and trucks are in most cases operated near or on the runways or taxiways only.

In all cases the safe operation of airside vehicles requires aerodrome operators to ensure that the personnel driving the vehicles received prior training and certification to gain specific knowledge regarding aerodrome operating regulations and specifics. This includes especially the training of required communication protocols, aerodrome lighting and signage as well as other aerodrome or air traffic control specifics.

Risk Factors

The operation of airside vehicles in a dynamic and sometimes complex environment like an aerodrome is associated with risks stemming from factors such as organizational, individual or environmental pressures, e.g. threats or hazards, and therefore requires sound mitigation procedures to prevent safety relevant events.

Typical risk factors for airside vehicle operation include, but are not limited to: 

• Weather (slippery or contaminated surfaces, wind or reduced visibility)
• Commercial pressures (time, ATC, schedule, disciplinary pressures)
• Language barriers (reduced or no aviation English proficiency of drivers)
• Low work experience of drivers (e.g. due to high staff turn-over rates)
• Vehicle status and vehicle specifics
  • Reduced visibility for drivers due to the vehicle’s size or shape
  • Reduced maneuverability of vehicles (e.g. by defects or design)
  • Reduced technical serviceability (e.g. due to lack of maintenance)
  • Lack of technical equipment (e.g. vhf-radio, moving airport map)
• Lack of procedures and/or lack of effective driver training and checking
• Lack of or ineffective regulatory oversight 

On top of occupational health and safety risk considerations for drivers and occupants of airside vehicles, especially those with specific technical functionalities bearing the risk for personal injury, the highest risks associated with the simultaneous operation of ground vehicles and flight operation on aerodromes are the risk for ground collision and the risk for runway incursions.  

Solutions 

Various ICAO documents (e.g. DOC 4444, 9870) are related to airside vehicles and include regulation and guidance on their operation. Among others these include the requirement that all vehicles employed on the manouevring area on controlled aerodromes shall be capable of maintaining two-way radiocommunication with the aerodrome control tower, the requirement to gain authorization from the control tower before entering the manoeuvring area or crossing a runway, or to stop immediately and contact the control tower if a vehicle driver is in doubt of her or his position.

On top of given ICAO and national regulation the Global Action Plan for the Prevention of Runway Incursion (GAPPRI) lists several additional recommendations to ensure and maintain safe operation of ground vehicles. Among these are the following recommendation for Aerodrome operators which should: 

• Ensure harmonised awareness of runway incursion risk management procedures, practices and issues among front-line operators (pilots, air traffic controllers and manoeuvring area vehicle drivers) through training and promotion, e.g. by using interactive scenarios simulating common runway incursion risks, quizzes or airport briefing containing airport-specific procedures, configuration and hotspots
• Annually evaluate the consistency of runway safety procedures for operations on the manoeuvring area of the aerodrome (pilots and manoeuvring area vehicle drivers) at LRST meetings, e.g. by reviewing recent incident reports to identify inconsistencies and gaps, by retrieving feedback from frontline operators and then systematically and critically reviewing procedures related to runway operations.
• In collaboration with the ANSP, periodically review the procedures for runway inspections and other runway works including runway inspections, both routine and full inspections, uni-directional lighting inspections as well as situational awareness procedures, standard inspection routs and timings and dashboard camera installation as well as their usage in inspection vehicles
• Ensure that drivers of vehicles operating on the manoeuvring area are familiar with the protected area map  and are briefed at the start of a shift, including providing awareness of safety-significant airport information, which drivers ought to check before the start of the mission.
• Ensure that vehicle driver procedures and guidance contain a requirement for explicit ATC clearances to enter or cross any runway, regardless of runway status (active/inactive).
• To minimise call sign confusion at aerodromes, aerodrome operators should ensure the use of predefined and process-specific unique call signs for manoeuvring area vehicles, e.g. ‘FOLLOW 1’, ‘INSPECT 1’, ‘FIRE 1’, ‘RESCUE A’, ‘CONSTRUCTION 1’, ‘TUG4’, ‘AIRFIELD 1’, ‘FUEL 2’, ‘SNOW 3’, ‘POLICE 2’, ‘SECURITY 1’, etc.
• In cooperation with ANSPs, implement communication procedures for airside vehicles’ drivers on what phraseology needs to be applied by both parties, including standard phrases for:
  • a. Radio checks and readability scale.
  • b. Radio communication failures (transmitting blind).
  • c. When a driver becomes lost or uncertain of the vehicle’s position in the manoeuvring area.
  • d. Position reporting.
  • e. Runway access and runway crossing requests
• Develop and implement a phased plan for use of one frequency and English language for all communication associated with the operation of a runway. Such a phased plan could be built upon the “4-4-Safety” initiative providing four standardized runway phraseologies to be used by drivers and controllers or the “Triple One” initiative aiming for one runway, one frequency, one language to be used for radio communication between drivers and controllers. Especially the aim to use English as the only language to be used will significantly help to improve the shared situational awareness of all front-line operators.
• Commensurate with the level and complexity of operations and the potential risk of a runway incursion, consider providing airside vehicle drivers with a real-time functionality for awareness and alerting to the potential for a runway collision between an aircraft and an airside vehicle and with real-time alerts when crossing into the protected area, such that drivers will be alerted in the event of a runway incursion
• Enable the tracking of vehicle movements in the manoeuvring area when possible. Facilitate situational awareness by adopting technologies that enable ATC and other parties to locate and identify traffic in the manoeuvring area
• Implement policies and means to support vehicle drivers with identification of hold limits in respect to the protected area of a crossing runway (e.g., marking, geofencing, airport moving map). 

Furthermore, regulators can support the recommendations above by promoting those and especially that all vehicles on the manoeuvring area are in radio contact with the appropriate ATC service (i.e., ground and/or the tower), either directly or through an escort. Additionally, regulators could promote ensuring that all aerodrome vehicles are assigned unique numbers or airside identification call signs for each airside vehicle to reduce the risk of vehicle-related call sign confusion. 

For more detailed information on the mentioned and proposed solutions see the GAPPRI document.

Accidents & Incidents

On 18 November 2022, the crew of an Airbus A320neo about to become airborne as it departed Lima were unable to avoid a high-speed collision with an airport fire appliance, which unexpectedly entered the runway. The impact wrecked the vehicle, killing two of its three occupants, and a resultant fuel-fed fire severely damaged the aircraft, although with no fatalities amongst its 107 occupants. The vehicle was found to have entered the runway without clearance primarily as a consequence of inadequate briefing for an exercise to validate emergency access times from a newly relocated airport fire station.

On 14 November 2019, a Boeing 737 was instructed to stop its night takeoff from Lyon at a low speed when the controller saw snow clearance vehicles entering the runway ahead. This vehicle group had been cleared to enter the active runway by the ground controller without any coordination with the runway controller and only the monitoring of surface movement radar and visual external scanning had removed the risk of a more serious consequence arising from the permitted incursion. The airport operator’s snow response plan was found not be specific to their airport and consequently of limited practical value.

On 21 January 2010, a Cargolux Boeing 747-400F was in collision with an unoccupied van whilst about to touch down on runway 24 at Luxembourg airport in thick fog following a Cat 3b ILS approach. It was subsequently established that a maintenance crew and their vehicle had earlier been cleared to enter the active runway but their presence had then been overlooked. Comprehensive safety recommendations to rectify deficiencies in both ATC procedures and prevailing ATC practices were made by the Investigation.

See here for more vehicle related events.

Further Reading

• ICAO Doc 4444 - PANS-ATM: Chapter 7, Section 7.5.
• European Action Plan for the Prevention of Runway Incursions, Appendix A - Communications Guidance
• European Action Plan for the Prevention of Runway Incursions, Appendix C - Airside Vehicle Driver Training
• ICAO Doc 9870 App A - Communications Best Practice
• ICAO Doc 9870 App D - Airside Vehicle Driving Best Practice
• An Airside Driver's Guide to Runway Safety: Airservices Australia, 3rd edition, June 2012.
• ACI Airside Safety Handbook, 4th edition, 2010
• AC 150/5210-20A: Ground Vehicle Operations to include Taxiing or Towing an Aircraft on Airports, FAA, September 2015