54TH ANNUAL CONFERENCE, Sofia, Bulgaria, 20-24 April 2015
WP No. 158
The Provision of Surveillance Approach and Aerodrome Control Services as Combined Function
Presented by PLC
This paper is dealing with a situation of ATCO working both aerodrome and approach from one working position. The paper presents relevant information for MAs and suggests a new policy.
1.1 In many countries around the world, a condition in which aerodrome controllers have ATS-Surveillance systems in the towers as assistance and information tool exists. In some cases an aerodrome controller is working both aerodrome and surveillance approach (“combined”). The basic premise of IFATCA is that each working position should be occupied by one licensed controller and the combined situation shall be avoided.
1.2 The main purpose of ATCO licensing is to enable each national aviation authority to regulate licensing of air traffic controllers within their state. The ATCO license identifies the holder as a person who is qualified to provide ATC service; it defines where the holder may provide ATC service, and contains details of the types of ATC service that the license holder may provide.
1.3 Simply, a controller assisted by an ATS-surveillance system solely provides ATS-Surveillance services, and an aerodrome controller solely provides aerodrome services. Sometimes, the condition of having surveillance systems available in control towers may create ambiguous situations where the distinction between visual and surveillance services is not clearly identified raising legal issues for ATS personnel and safety issues for the provision of the services. Such situations, in incidental cases, are supported by regulators and ANSPs for economic reasons.
1.4 This paper considers surveillance means used for airborne operations in the vicinity of an aerodrome, and not with ground movement means (such as ASMGS), which are also surveillance systems.
2.1 ATCO licensing
ATCO license identifies the holder as a person who is qualified to provide ATC service, and it indicates the ATC unit where the holder may provide this service. Two main approaches define ATCOs licensing: the global approach of ICAO and the European approach of EASA.
2.1.1 ICAO definitions
Standards and recommended practices for the licensing of ATCOs are provided by Annex 1, Personnel Licensing, to the convention on International Civil Aviation. One of ICAO’s main tasks in the field of personnel licensing is to foster the resolution of differences in licensing requirements and to ensure that international licensing standards are kept in line with current practices and probable future developments.
For working both tower and approach, ATCO should have two ratings. Annex 1 guides that:
“when two ratings are sought concurrently, the licensing authority in each country shall determine the applicable requirements, and they shall not be less than those of the more demanding one”.
ICAO defines the following categories of ATCO ratings (ICAO, Annex 1, Chapter 4 – Personnel Licensing):
a) aerodrome control rating;
b) approach control procedural rating;
c) approach control surveillance rating;
d) approach precision radar control rating;
e) area control procedural rating; and
f) area control surveillance rating
2.1.2 European regulations
According to Commission Regulation (EU) No. 805/201, the ATCO license can have the following ratings and associated endorsements:
- Aerodrome Control Visual (ADV)
- Aerodrome Control Instrument (ADI) with at least one endorsement: Tower Control (TWR); Ground Movement Control (GMC); Ground Movement Surveillance (GMS); Air Control (AIR); Aerodrome Radar Control (RAD)
- Approach Control Procedural (APP)
- Approach Control Surveillance (APS) with endorsements: Radar (RAD); Precision Approach Radar (PAR); Surveillance Radar Approach (SRA); Automatic Dependent Surveillance (ADS); Terminal Control (TCL)
- Area Control Procedural (ACP)
- Area Control Surveillance (ACS) with endorsements: Radar (RAD); Automatic Dependent Surveillance (ADS); Terminal Control (TCL); Oceanic Control (OCN)
2.2 ATS surveillance systems in the aerodrome control service
ICAO Doc. 4444, 22.214.171.124, defines 4 functions to be provided while using ATS surveillance systems by an aerodrome control service:
a) Flight path monitoring of aircraft on final approach;
b) Flight path monitoring of other aircraft in the vicinity of the aerodrome;
c) Establishing separation between succeeding departing aircraft (specified in Doc 4444, 8.7.3); and
d) Providing navigation assistance to VFR flights.
In general, for separation between arriving and departing aircraft, while using ATS-surveillance equipment, an approach control surveillance rating is needed. Furthermore, the use of ATS surveillance systems in the aerodrome control service is permitted subject to conditions prescribed by the appropriate ATS authority and its authorization.
Section 126.96.36.199 states that:
“In prescribing conditions and procedures for the use of ATS surveillance systems in the provision of aerodrome control service, the appropriate ATS authority shall ensure that the availability and use of an ATS surveillance system will not be detrimental to visual observation of aerodrome traffic.” (ICAO Doc. 4444, Chapter 8, ATS Services)
There is no ICAO definition for the “combined” function of an ADI controller, rated both ADI and APS, using ATS- Surveillance systems to provide approach service while providing aerodrome control service.
In addition, considering aerodrome towers functions (ICAO Doc 4444, 7.1.) the aerodrome controller main and important role is maintaining a continuous watch on all flight operations on and in the vicinity of the aerodrome as well as vehicles and personnel on the maneuvering area. Watch shall be maintained by visual observation.
Visual observation in ATM is defined as:
“observation through direct eyesight of objects situated within the line of sight of the observer possibly enhanced by binoculars.” (ICAO Doc. 4444, Chapter 1, Definitions)
2.3 ADV vs. ADI rating
An aerodrome controller who works in a position where there are published instrument departure or approach procedures associated with the use of surveillance systems has to hold an ADI rating with the endorsement of RAD. However, there are no rating endorsements needed for a controller who holds ADV rating. So, theoretically, an aerodrome controller working where there are no instrument procedures can use surveillance means without any rating endorsements. This is a regulatory gap caused due to the development of aerodromes and technology in the last years.
Since ICAO Annex 1 was first published, there has been a significant increase in the volume of air traffic. Although Annex 1 has been amended, the basic licensing procedures, including the ratings, have remained unchanged. Both increase in traffic and new technology have led to more complex procedures for ATCOs, which in turn requires ATCOs to become more specialised and to use more advanced controlling techniques.
2.4 There are countries where using surveillance as a separation tool requires radar (RAD) rating, while using it as information and assistance tool does not.
Then, a distinction should be made between two cases:
1. Aerodrome controller (ADI rating) uses radar for separation (RAD endorsement).
2. Aerodrome controller (ADI rating) uses radar as information.
2.5 However, PLC is convinced that ATS- Surveillance systems, as any other tool in the provision of air traffic services, should be used only when a specific training is carried out and appropriate operational and legal standards are in place. All other circumstances must be avoided. In this specific situation, an aerodrome controller using ATS- Surveillance systems in the provision of all the functions listed in paragraph 2.2 (ICAO DOC 4444, 188.8.131.52), or some of them, must have a surveillance rating, which in practice states that he/she is able to use the information displayed as requested. This training must be commensurate to the requested tasks; consequently the following aerodrome surveillance rating may be restricted to provide these functions listed by ICAO. An input given from several ANSPs
2.5.1 In few cases it was observed that surveillance approach control functions are provided by the tower controller during “quiet periods” shows that an APS rating holder is put into the ADI position. The aim is increased efficiency, which obviously translates as reduced manpower. In these cases, both surveillance approach (vectoring) and tower role are done by one controller from the tower/ aerodrome position. Usually, when this method is in operation it is on very low volume of traffic times, so the saving is only one ATCO. A specific example can be using this operational mode at the end of the day when traffic decreases to practically none. A locally grown habit might create a situation in which the APS ATCO stays downstairs at the radar floor as an extra pair of eyes, while one controller works combined aerodrome and approach control from the tower. Evidence describes that the APS controller who stays downstairs saves the day of the combined tower/ approach controller on more than one occasion. It seems that it harms service provision from the ADI controller, as delays can cause for aircraft since the tower controller is busy giving vectors, which should be APS ATCO’s job.
2.5.2 In other cases it was observed that in civil towers TWR ATCOs have an ATS- Surveillance system available, used for separation tasks according to ICAO definitions mentioned above only (item 2.2). Also, TWR controllers do have an approach rating when finalizing their full OJT. Also if ATCOs do have an approach position in the tower cabin, a combination with the tower functions is never executed by a single ATCO.
2.5.3 Another example showed a situation in which aerodrome controllers do provide surveillance approach service from a TWR position when the radar approach unit is closed (during the night, for example). In this case only one controller occupies the tower, and only under specific conditions surveillance approach service may be provided. The controller has to be licensed as a radar approach controller and it is prohibited to combine aerodrome control and approach control at the same time. When having both aerodrome and approach traffic in the same time, the IFR approaching/departing traffic must continue through procedural separation via IFR procedures and routing.
2.6 IFATCA’s Policy
At conference in Gran Canaria, Spain, 2014, a policy change in IFATCA’s definition for SPO/ LPO (Single/ Lone Person Operation) was accepted and defines:
“Single or Lone Person Operations (SPO/LPO) shall be avoided. The use of SPO/LPO should be strongly discouraged by MAs, both through their ANSP and their regulator. If providers choose to operate SPO/LPO, they shall bear the responsibility for the resulting risk(s) to the system. If SPO/LPO occurs, appropriate measures shall be taken to ensure that the SPO/LPO situation changes to another manning scenario. Until such time, measures shall be taken to mitigate all impacts of SPO/LPO, such as, but not limited to traffic regulation, work break provisions, informing neighboring ATC units. Procedures shall be in place to implement such measures in an efficient way, not increasing the workload of the ATCO.” (IFATCA WP No. 153, Clarification of Sector Manning Principles, Gran- Canaria, 2014)
It follows that staffing working positions with one ATCO is against IFATCA’s policy, and in any case has to be according to ICAO’s definitions. Moreover, it is the MA’s responsibility to ensure the proper attitude to the subject, as stated on IFATCA’s policy (2014):
|“The use of SPO/LPO should be strongly discouraged by MAs, both through their ANSP and their regulator. When providers choose to do so, they must bear the responsibility for the resulting risk(s) to the system. An ATCO shall not be held liable for incidents or accidents resulting from an ANSP imposing the use of SPO/LPO.”|
3.1 An aerodrome controller has to maintain continuous observation with the maneuvering area and traffic at all times. A distraction from this duty can cause severe safety outcomes.
3.2 ATCOs licensing is the basis for staffing working positions.
3.3 There is a difference between ICAO definitions and the European definitions (provided by Eurocontrol) of ATCOs licensing.
3.4 ICAO Annex 1, Personnel Licensing, provides standards and recommended practices for the licensing of ATCOs. Since it was first published, there has been a significant increase in the volume of air traffic, and although it has been amended, the basic licensing procedures, including the ratings, have remained unchanged.
3.5 PLC is in the opinion that a generic policy in regard to simultaneous working positions should be addressed.
It is recommended that:
4.1 IFATCA policy is:
ATCOs shall not provide surveillance approach service and aerodrome control service simultaneously.
and is included in the IFATCA Technical & Professional Manual.
IFATCA Technical and Professional Manual, 2014.
IFATCA WP No.153 Clarification of Sector Manning Principles, Gran Canaria, Spain, 2014.
ICAO Doc. 4444, Chapter 7, Procedures for Aerodrome Control Service.
ICAO Doc. 4444, Chapter 8, ATS Services.
ICAO, Annex 1, Chapter 4, Personnel Licensing.
SKYbrary, Regulation 805/2011, Rules for Air Traffic Controllers’ Licences.
Last Update: October 1, 2020