59TH ANNUAL CONFERENCE, Singapore, 30 March – 3 April 2020
WP No. 156
The Use of Aerodrome Control Frequency for Communications of Vehicle Drivers
Presented by PLC
|IMPORTANT NOTE: The IFATCA Annual Conference 2020 in Singapore was cancelled. The present working paper was never discussed at Conference by the committee(s). Resolutions presented by this working paper (if any) were never voted.|
A runway incident involving a vehicle operating on the runway highlighted a safety concern that vehicle drivers remain on ground control frequency instead of the aerodrome control frequency. Some studies were made and this paper will discuss about the importance of “one runway – one frequency – one language” principle, and other related matters.
Aerodrome Control Frequency – Frequency used by aerodrome controller as per ICAO Doc 4444 18.104.22.168.
Ground Control Frequency – Frequency used by ground controller as per ICAO Doc 4444 22.214.171.124.
2.1. According to the ICAO Doc 10004, 2017-2019 Global Aviation Safety Plan (2016), Runway Safety, Controlled Flight into Terrain (CFIT) and Loss of Control in Flight (LOC-I) were identified as the top three high-risk accident categories (ICAO Doc 10004, para 3.1.2 & 3.1.3). While these three categories account for 60.57 per cent of all fatalities worldwide, over half of the accidents worldwide involved Runway Safety events (ICAO Doc 10004, para 3.1.4a).
2.2. Runway safety events include abnormal runway contact, bird strikes, ground collision, runway excursion, runway incursion, loss of control on the ground, collision with obstacle(s) and undershoot/overshoot (ICAO Doc 10004, para 3.1.2).
2.3. On 30th December 2007, a B733 hit a service car during take-off at LROP (Bucharest Henri Coandă International Airport). For a detailed breakdown of the incident please refer to Appendix A.
2.4. Upon investigation, a number of factors contributing to the incident were identified. One of the factors was that the vehicle was on the ground control frequency instead of the aerodrome control frequency.
2.5. This paper will analyse the operation of ground vehicles on the aerodrome control frequency and the problems that such operation may cause.
3.1. ICAO’s Doc 9870 Manual on Prevention of Runway Incursion states that:
“All communications associated with the operation of each runway (vehicles, crossing aircraft, etc.) should be conducted on the same frequency as utilized for the take- off and landing of aircraft.” (ICAO Doc 9870, para 4.2.6)
3.2. The European Action Plan for the Prevention of Runway Incursions [EAPPRI] (2017) also states that:
“It is recommended that communications for all operations on a runway (landing, departing, crossing aircraft, vehicles crossing and runway inspections etc.) take place on the VHF frequency assigned for that runway; this will help to maintain high levels of situational awareness.” (EAPPRI V3.0, p.39)
3.3. The above two points are frequently referred to as “One Runway, One Frequency” principle. At some aerodromes this principle has been extended to “One Runway, One Frequency, One Language” or “Triple One” (HindSight19 Summer 2014, p35).
3.4. The discussion below would be broken down into two parts, the first will focus on “One Runway, One Frequency” and the second on “One Language” criteria.
A. “One Runway, One Frequency”
3.5. The current ICAO recommended practices regarding “One Runway, One Frequency” are detailed at 2.1.
3.6. The EAPPRI’s recommended practice is:
“When practicable, improve situational awareness, by implementing procedures whereby all communications associated with runway operations are on a common or cross-coupled frequency.” (EAPPRI V3.0, 1.3.5)
3.7. Below are some incidents in which the vehicles involved were not operating on the aerodrome control frequency:
3.8. Putting a vehicle on the aerodrome control frequency may not only enhance situational awareness of the aerodrome controller, but also of the pilot and the vehicle driver.
3.8.1. Apart from visually observing other traffic without assistance from other equipment, a pilot can only build a mental traffic picture from those aircraft transmitting on the same frequency. (HindSight23 (2016), p8).
This is very important especially when visibility is poor. As from the table above, more than half of the incidents occurred during poor visibility or night time.
3.8.2. Drivers’ situational awareness will also be improved by being on the aerodrome control frequency. (HindSight23 (2016), p53)
3.9. The Final Report on the collision between a Cargolux operated Boeing 747-400F Registered LX-OCV and a maintenance van on Runway 24 at Luxembourg Airport (ELLX) on 21 January 2010, 11:53 UTC (2012) by Administration des Enquêtes Techniques (AET), Luxembourg stated (referencing a conclusion from an EuroControl study) the following points as the benefits of putting ground vehicle on aerodrome control frequency (p55):
3.9.1. The potential for errors in co-ordination between GMC (Ground Movement Control) – AIR Controllers was significantly reduced.
3.9.2. Situational awareness of both the AIR and GMC Controller was significantly increased.
3.9.3. Situational awareness of pilots is improved regarding tugs and vehicles crossing or operating on the runway.
3.9.4. Situational awareness of Tug and vehicle Drivers is improved regarding aircraft on approach, crossing or taking-off.
B. “One Language”
3.10. Current ICAO “One Language” practice is found in ICAO Doc 9870 Manual on Prevention of Runway Incursions. It states:
“All communications associated with runway operations should be conducted in accordance with ICAO language requirements for air-ground radiotelephony communications (Annex 10 — Aeronautical Telecommunications, Volume II, Chapter 5, and Annex 1 — Personnel Licensing, Chapter 1 and Appendix 1, refer). The use of standard aviation English at international aerodromes will improve the situational awareness of everyone listening on the frequency.” (para 4.2.5)
3.11. The EAPPRI’s recommended practice is:
“Where practicable, improve situational awareness by conducting all communications associated with runway operations using aviation English.” (EAPPRI V3.0, 1.3.4)
3.12. The accident in Reykjavik, identified in table 1, gives some good insight on the issue. The Final Report by Rannsóknarnefnd samgönguslysa (The Icelandic Research Committee for Transportation Accidents) [case no. 18-007F002] (2019) found that although the main cause of the incident was the aircraft taking-off without clearance, the pilot was not aware there was a sanding vehicle on the runway because:
3.12.1. The sanding vehicle was on another frequency while the aircraft was on tower frequency (p5, para 2,3)
3.12.2. The “runway under sanding” information was not picked up by the pilots because that was transmitted in Icelandic. (p6 para 7)
3.13. A safety recommendation was made:
“That ICETRA reviews Iceland AIP GEN 126.96.36.199 for BIRK and recommend that English is always used for ATC radio communications when at least one airplane on the ground and/or tower frequencies communicates in English.” (p8 para 2)
C. Difficulties in Apply “One Runway, One Frequency” and “One Language”
3.14. A survey regarding the situation of the usage of aerodrome control frequency for ground vehicles has been conducted from June to November. The survey was conducted via Google forms and sent to all MAs via the IFATCA office. A total of 40 responses were received.
3.14.1. Approx. 60% of the responses indicated that they are not practicing “One Runway, One Frequency” policy.
3.14.2. Among such, Approx. 70% allows the use of language other English, and approx. 90% do not have plan to change.
3.15. A follow up questionnaire was sent to MAs which expressed difficulties in applying “One Runway, One Frequency” or “One Language” operations/policies/principles to understand the barriers involved. From the responses received, reasons for not implementing “One Runway, One Frequency” operations included:
In certain aerodromes, the power of the radio on vehicles is not enough to maintain a clear transmission with the tower.
3.15.2. RT Discipline
Drivers are only trained with basic radio operation technique. They may not understand the operating environment of the tower to identify moments critical to ATC operations. Transmission at wrong timing or jamming the aerodrome control frequency may not be desirable.
3.15.3. “One Language”
Drivers at certain aerodromes may have poor English language skills or not speak English at all. Some aerodromes thus choose to have a separate frequency or communication means for drivers to maintain the “One Language” principle over the aerodrome control frequency.
3.15.4. Operation Requirement
At certain aerodrome, communications for certain operations near the runway may be too complex or take up too much airtime. Putting all these communications onto the aerodrome control frequency may have operational impact on ATC.
3.16. Reasons for not implementing “One Language” included:
3.16.1. Language Proficiency
English may not be the driver’s first language at certain aerodromes. Extra training and necessary certification may be required for them to use English on radio frequencies.
3.16.2. Social Structure
In certain regions, English proficiency may reflect education level or social status. Drivers with strong English skills may find more desirable jobs elsewhere.
4.1. With all the above examples and studies, no matter the “One Runway, One Frequency” or the “One Language” principle, both would help to improve the situation awareness for all parties involved in runway operation, namely, ATC, pilots and vehicle drivers.
4.2. However, there exist barriers in certain places around the world which hinder the application of “One Runway, One Frequency, One Language” principle.
4.3. One of the studies by Skybrary (2014) stated that:
“English language proficiency for drivers is a key consideration and the lack of it is often the main factor holding back the adoption of Triple One.”
this also concurs with the response from MAs in point 3.15.3 and 3.16.1. The same study suggests that drivers with different tasks (access to or crossing the runway) may require different level of language proficiency (para Q5).
4.4. The same study also found that the benefit of enhanced situational awareness actually outweighs any perceived risk associated with overlapping pilot/controller/driver transmissions, interference etc. (para Q6).
4.5. This is a good chance to raise the awareness that for safe aerodrome operation, not just ATC and pilot, but also vehicle drivers shall be also included in the roadmap. That will include items like operating procedure, training, licensing, equipment and language proficiency. Aerodrome authorities, ATC units and pilots shall all understand each other’s concerns, limitation and role on the runway operations.
5.1. In light of what has been discussed in this working paper, the following policy is proposed for adoption and incorporation in the IFATCA Technical and Professional Manual (TPM):
ADME 2.17 – RUNWAY IN USE – COMMUNICATION REQUIREMENTS
IFATCA supports the concept of “One Runway, One Frequency, One Language”.
Vehicle drivers operating within the aerodrome controller’s area of responsibility shall establish and maintain direct communications with the aerodrome controller via the aerodrome control frequency. All communications on the aerodrome control frequency shall be conducted in the same language, preferably English.
ICAO Doc 10004 2017-2019 Global Aviation Safety Plan (2016).
ICAO Doc 4444 PANS-OPS 16th Edition (2016).
ICAO Doc 9870 Manual on the Prevention of Runway Incursions (2007).
ICAO Annex 10 Aeronautical Telecommunications.
ICAO Annex 14 Aerodromes Volume 1.
ITU Radio Regulations Edition of 2016 Volume 1.
EuroControl (2014), HindSight19 Summer 2014.
EuroControl (2016), HindSight23 Summer 2016.
EuroControl (2017), European Action Plan for the Prevention of Runway Incursions EAPPRI V3.0.
Administration des Enquêtes Techniques (AET), Luxembourg (2012), Final Report on the Collision between a Cargolux operated Boeing 747-400F Registered LX- OCV and a Maintenance Van on Runway 24 at Luxembourg Airport (ELLX) on 21 January 2010, 11:53 UTC.
Rannsóknarnefnd samgönguslysa, Iceland (2019), The Final Report on Aircraft Serious Incident [case no. 18-007F002].
Skybrary (2014), Use of aerodrome Tower VHF frequency by vehicle drivers involved in runway operations/Responses. Retrieved from https://www.skybrary.aero/index.php/Use_of_aerodrome_Tower_VHF_frequency_by_vehicle_drivers_involved_in_runway_operations/Responses
Autoridade de Aviação Civil da Região Administrativa Especial de Macau (2019), Aviation Occurrence Investigation Final Report [INCID/02/2018] (https://www.aacm.gov.mo/images/download1/2019072211113310.pdf)
Appendix A – Breakdown of the incident at LROP (B733 vs vehicle)
Date: 30th December 2007
Aircraft damage: substantial damage beyond repair
Departing aerodrome: LROP
Destination aerodrome: HESH
Weather: low visibility due fog
07:53 the shift supervisor was contacted by the lights maintenance crew to ask between what hours RWY 08R was free so they could clean the RWY lights, the shift supervisor informed them that he would call them as soon as he had an answer. The shift supervisor talked to ATCO EXE and GND.
08:49 ATCO GND talked to the maintenance crew on the ground-ground frequency the details for entering the RWY.
08:56 ATCO GND called the maintenance crew and cleared them to enter the RWY.
08:57 The maintenance crew confirmed that they are on the RWY.
08:59 ATCO GND told the crew than airplane was starting-up and to be prepared to vacate the RWY.
09:02 ATCO GND required the maintenance crew to vacate the RWY, and the RWY was confirmed vacated 09:04.
09:06 ATCO GND cleared TAROM for push back and start-up.
09:08 the shift was changed for the GND position.
09:08 the maintenance crew requested and was cleared to enter the RWY (GND coordinated with EXE).
09:09 ATCO EXE asked GND “what is on the RWY”, GND replied “The maintenance crew, i just cleared them…”
09:23 ATCO GND cleared TAROM to taxi to HP RWY 08R with follow-me in sight, without checking if the RWY is cleared. After TAROM reported reaching HP RWY 08R, the aircraft was transferred to ATCO EXE.
09:25 Tarom contacted Otopeni TWR, and was cleared to line-up RWY and reported ready for departure by ATCO EXE without checking that the RWY was cleared.
09:26 Tarom reported ready for departure and was cleared for take-off by EXE without checking the RWY.
09:26:41 ATCO GND called the maintenance crew but there was no answer, after 10 seconds he called again.
09:26:50 The maintenance crew responded “I’m listening” and GND asked “RWY is cleared, right?”, the maintenance crew pressed the PPT button but there was no transmission.
09:26:57 Tarom pilot asked “what are those flashing lights”.
09:27 Tarom hit the maintenance car.
Last Update: October 2, 2020