Description

One of the key requirements for the safe deployment of vehicles airside, on manoeuvring areas shared with aircraft, is that their drivers (or their front seat colleagues) are competent in RTF communication with ATC. Airport Authorities usually have overall responsibility for setting and monitoring standards, but the agency operating a vehicle has direct responsibility for ensuring that ATC communications with their vehicle is of a standard which will preclude any contribution to diminished safety standards for aircraft. Whilst some vehicles will be operated directly by the airport authority, most will be operated by various service providers. The chance of disaster is at its greatest when the possibility exists of an aircraft at speed on a runway, during the take off or landing roll, encountering ground vehicles. 

Who are the Drivers?

Apart from Airport Authority personnel who may fulfil many different roles including the very specialist RFFS, it is likely that airside drivers will also include persons working airside in connection with:

• Aircraft Maintenance;
• Aircraft Ground De/Anti-Icing;
• Aircraft and Passenger Handling;
• Aircraft Catering;
• Aircraft Cleaning;
• Aircraft Refuelling;
• Passenger and Crew transport;
• Cargo;
• Visiting vehicles requiring escort.

Where Are They Driving?

All airport operators should have a system for issuing airside driving permits; this should include a process for validating competency in the effective use of ATC radio communications. On top of this requirement, the Global Action Plan for the Prevention of Runway Incursions (GAPPRI) suggests that aerodromes consider implementing a three-level scheme for aerodrome driving permits: apron only, manoeuvring area (excluding runways) and runways. Furthermore, it is not only suggested to define driver training programmes which include runway incursion risks and mitigations, but also to periodically assess formal manoeuvring area driver permits, the training and refresher programmes against training requirements.

The Key Elements of Acceptable ATC Radio Communication for Vehicle Drivers

• At larger airports, it is usual to find different parts of the airport controlled by ATC using different radio frequencies, often with different radio call sign endings. To minimise call sign confusion at aerodromes GAPPRI recommends that aerodrome operators should ensure the use of predefined and process-specific unique call signs for manoeuvring area vehicles.
• Speak clearly and at a moderate speed, especially if the speaker has marked regional or non-native accent.
• Always listen before starting a transmission and be aware that there may be a short gap between a transmission by other traffic or ATC and the corresponding reply.
• Press the radio transmit switch before beginning to speak and do not release it until a transmission is finished, otherwise it may be ‘clipped’ and an important part of the content lost.
• Know the airport layout and the location and designation of all runways, taxiways and holding points.
• Find out before setting out which runways are in use and the location of any “work in progress” or taxiway closures which may affect usual routes. In addition, GAPPRI suggests that vehicle drivers are briefed at the start of a shift, including providing awareness for safety-significant airport information, which should also be reviewed again before the start of the mission of by the vehicle driver. (Effective briefings are an integral part of everyday flight operations so that this general concept and layout of briefings can be used by vehicle drivers as well.)
• Strictly adhere to vehicle speed limits; ATC will assume this if they need to amend a current clearance.
• Use marked roadways where available
• If in any doubt about an ATC instruction, obtain a repeat by saying “Say Again" (or “Say Again all before/after/between…”). Do not proceed beyond the previous clearance limit until a response has been obtained and understood. This is especially important regarding runway entrance and crossing. Therefore, GAPPRI recommends that vehicle driver procedures and guidance contain a requirement for explicit ATC clearances to enter or cross on any runway, regardless of runway status (active/inactive).
• Ensure that all ATC Clearances are read back in full before proceeding.
• Remember the designated radio call sign for either the driver or the vehicle and:
  • listen out for it at all times
  • use it to identify each transmission made.
• Listen to aircraft/ATC communications and where possible, use the information acquired to build up a mental map of what else is moving - or about to be moving - in the area in which you are at present, or where you are about to proceed. This is called maintaining 'situational awareness' and is important for flight crew too. Therefore, GAPPRI recommends that aerodrome operators 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. Furthermore, it is recommended that aerodrome operators implement policies and means to support vehicle drivers with identification of hold limits in respect to protected areas of a crossing runway (e.g., marking, geofencing, airport moving map).
• If the vehicle being driven has an automatic position transmitter fitted which allows ATC to see its position on a remote display, then this must be switched on whenever this is required. Enabling the tracking of vehicle movements in the manoeuvring area when possible is also a general recommendation by GAPPRI.
• If a vehicle driver becomes uncertain of his/her position, the vehicle should be stopped immediately and ATC informed. Further movement should await ATC instructions.
• If the occupants of a vehicle operating under ATC Control need to work outside it, then they must have a means of hearing calls from ATC - a vehicle loudspeaker or portable radios - and these must be audible even at the high noise levels that are likely to be experienced.
• Be aware of local radio failure procedures and be prepared to recognise the signs that this has occurred - whether wholly or only in respect of vehicle reception or (apparently) vehicle transmissions.
• Review airport driver training materials for your specific airport regarding airport signage and markings, hot spot locations, and construction.

For more detailed information see GAPPRI recommendations ADR 12, 13, 14 and 22, 23, 24, 30, 31, 33.

Standard Phraseology

It is important that radio communications are concise so that the amount of transmission time is minimised, but also even more important that they are fully understood. In many cases, single words are used which are equivalent to a phrase. Sometimes, even single words which are not commonly encountered in everyday use are used by ATC as important instructions. Also, where letters or numbers have to be spoken individually eg “Hold at C12” then it is important that the international radio telephony alphabet is used. To further enhance the prevention of runway incursions GAPPRI recommends that both, Aerdrome Operators and Air Navigation Service Providers develop and implement a phased plan for use of one frequency and English language for all communication associated to the operation of a runway. This includes initiatives like „Triple One“: One Runway, One Frequency, One Language (English) or 4-4-Safety: Safe Runway Phraseologies proposing professional language for runway vehicle drivers as means to further improve communications for all operations on a runway. For more detailed information see GAPPRI recommendations ADR 25 and ANSP 10.

Active Runways

Many airports have more than one runway and if so, it is important to be aware which runways are in use or ‘active’. It is always necessary to obtain a specific clearance to cross any runway, active or inactive.

Towing

Persons authorised to drive and/or operate ATC radio communications in vehicles which tow aircraft should be very carefully selected and trained by their employers, with special reference to any restricted visibility from the vehicles used and their awareness of the size of aircraft types which may be towed. The potential effect of not complying with ATC clearances when towing aircraft, or if the link between the towing vehicle and the aircraft nose landing gear fails, is clearly much greater than for a vehicle on its own.

Low Visibility Procedures (LVPs)

An airport which has approved procedures to continue with aircraft movements in low forward visibility will have a formal set of procedures which apply whenever Low Visibility Procedures (LVP) are declared to be in force. Typically, all non-essential airside vehicular traffic will be prohibited and remaining traffic will be required to drive within reduced speed limits and use different runway entry holding points. In addition, taxiway and runway lighting will be in use which may not necessarily be the case otherwise during daylight.

Proactive Reporting

The most important aspects of driving under ATC control are:

• to follow all clearances as given, and
• to maintain situational awareness.
• to challenge and check with ATC if any doubts exist about clearances or information received. Any vehicle occupant’s doubts should be treated seriously and resolved by checking with ATC.

Additionally, it is part of the driver's responsibility to be observant and to make radio reports to ATC of:

• any apparent external abnormalities in respect of an aircraft in the vicinity;
• bird or other wildlife activity which may be unknown to ATC and apparently hazardous to aircraft;
• any significant FOD sighting;
• any other hazard to aircraft or personal safety which is seen from the vehicle.

Escorted Vehicles not in Radio Contact with ATC

If appropriate procedures have been agreed with ATC, it may be permissible for a radio equipped vehicle driven by a suitably authorised permit holder to escort a visiting vehicle within the ATC-controlled zone. Such arrangements carry a heavy responsibility upon the escorting driver to ensure that the driver of the escorted vehicle has been properly briefed and to monitor the position of the other vehicle at all times to ensure both vehicles comply with ATC clearances. This particularly applies to position reports which will need to be made only when the whole ‘convoy’ is in compliance.

Local Runway Safety Teams (LRST)

There will often be a Local Runway Safety Teams (LRST) at an airport. If there is, it will usually be run by the Airport Authority and attended by ATC. It exists to monitor issues which may affect runway safety and is therefore very concerned with runway crossings by vehicles and situational awareness of their drivers, both of which are heavily dependent upon high standards of radio communication. It is there both to receive input and to help co-ordinate any action which may be needed to deal with problems and issue alerts.

Accidents and Incidents 

• 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.
• On 28 January 2019, a departing Embraer 170-200 narrowly avoided collision with part of a convoy of four snow clearance vehicles which failed to follow their clearance to enter a parallel taxiway and instead entered a Rapid Exit Taxiway and continued across the runway holding point before stopping just clear of the actual runway after multiple calls to do so. A high speed rejected takeoff led to the aircraft stopping just before the intersection where the incursion had occurred. The Investigation noted the prevailing adverse weather without attributing any specific cause to the vehicle convoy’s failure to proceed as cleared.
• On 30 November 2019, as an Airbus A320 was about to touch down in normal night visibility at Toyko Haneda, a runway maintenance contractor’s car began to cross the same runway without clearance, as the driver believed this was not necessary. Separation reduced to 1,417 metres shortly before the A320 began to clear the 3,000 metre runway. Planning for overnight work on the intersecting runway was found to have been inadequate and multiple related training requirements and procedures were enhanced by both the aviation regulator and the airport operator. The incursion was assessed as ICAO Category "C."
• 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 20 July 2023, a Boeing 737-800 was given a night landing clearance at Kansai with the controller unaware a runway inspection in the landing direction was in progress. When the vehicle driver heard this clearance, they identified the approaching aircraft position and estimated their inspection could be completed without impeding the inbound aircraft but on checking, were instructed to exit the runway at once and did so. Minimum aircraft/vehicle separation was 3,480 metres. The immediate cause of the potential conflict was controller error when various ground movement activities were occurring towards the end of an otherwise quiet night shift.

Further Reading

• UK CAA A Reference Guide to UK Phraseology for Aerodrome Drivers
• An Airside Driver's Guide to Runway Safety: Airservices Australia, 3rd edition, June 2012.
• FAA Guide to Ground Vehicle Operations, FAA.
• 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 Practices
• 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
• Network Manager Safety Study: The Impact of Airside Drivers on Runway Safety, EUROCONTROL, August 2015.