Responsibilities and Functions of Aerodrome Control with Regard to Surface Movements (Legal Aspects)

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Responsibilities and Functions of Aerodrome Control with Regard to Surface Movements (Legal Aspects)

36TH ANNUAL CONFERENCE, Taipei, Taiwan, 17-21 March 1997

WP No. 163

Responsibilities and Functions of Aerodrome Control with Regard to Surface Movements (Legal Aspects)


The subject of responsibility and functions of aerodrome control were properly outlined by a SC4 working paper for IFATCA 1996, where the terms of reference of the controller were highlighted, hence areas of concern that prohibit the controller from achieving set objectives became apparent. These shortcomings in the control of aerodrome traffic make it imperative to put in place measures to protect the controller from possible criminal prosecution. The ethics of criminal liability as far as the controller is concerned have never been outlined.

Cases involving controllers have been dealt with in accordance with ‘criminal law’, but it is clear that according to the nature of most statutory authorities, a statutory undertaker may escape liability in “Tort”, but what is not clear is the principle upon which such exemption from liability rests. However the determination of whether or not a claim should be made against the state for negligence in the operation of Air Traffic Control facilities must depend upon the facts of each particular case; where the factors affecting the provision of safe Aerodrome Control play an important part.


The primary objective of Aerodrome Control is to promote a safe, orderly and expeditious flow of air traffic on and in the vicinity of an aerodrome with the object of preventing collisions between:

a)  Aircraft flying in the traffic circuit around an aerodrome;

b)  Aircraft operating on the manoeuvring area;

c)  Aircraft landing and taking off;

d)  Aircraft and vehicles operating on the manoeuvring area;

e)  Aircraft on the manoeuvring area and obstructions on that area.

(ICAO Doc. 4444 Part V Aerodrome Control Service)


However, there are limitations within the system of Air Traffic Control due to the rapid advance of the aviation industry and the somewhat limited advance in technology of ATC, giving rise to the need to readdress the factors preventing the controller from achieving set objectives as highlighted by SC4. (Obstructed visual observation from the control tower, restricted parking areas, SMGCS, Low visibility procedures, apron management service, surface movement radar). In the case of the aerodrome controller, clearance and instructions issued must be based on the knowledge and awareness of the exact position and movement of aircraft and vehicles.

The primary factor is ‘control’ so as to achieve ‘safe’, but this might be jeopardised when the areas of responsibility between runway control and ground movement control overlap, or when there is use of unqualified personnel, or the position of the tower does not afford the controller an overall view of the aerodrome. It takes time and money to plan Air Traffic Control facilities, hence planning must not be directed at the prevailing conditions, but rather at conditions that are likely to exist in years to come. Therefore today’s modern automation does not always provide the desired service, nor does it alleviate all the pressures on the controller.

Of all the factors that affect aerodrome control, poor weather has the most adverse effect on the controller’s ability to achieve his task. The controller is still governed by the same policies as in VMC, although there are some procedures to handle this abnormality. However, with all the ‘machinery’ in place to safeguard the pilot (i.e. CAT 2/3 ILS approaches, flow control, TCAS), the controller still has to provide positive control based on the position report of the aircraft, with service vehicles operating at the same volume, although following set procedures.

The question that arises is what happens to the unfamiliar pilot, or the misunderstood clearance at an aerodrome with an incomplete taxi system, or with a poor communication system, or with a SMR that does not provide an adequate service. And what of the human factor element? In such circumstances a controller may not be guilty of negligence in the classical sense, nor the company/government guilty of negligence in failing to provide the controller with better more up to date or more adequate equipment and working conditions, but rather the environment created by the dynamic aviation scenario.

It is in the conditions stated above, that states/governments may be liable under statutory instruments/acts, for errors of Air Traffic Control whilst performing their operational duties, notwithstanding the discretionary function. In this instance the discretion of the controller exercised in poor visibility and when operating in conjunction with an Apron Management Service, which is manned by unqualified personnel, must not be judged but regarded as a decision taken with due caution. Apron Management Service may render an essential service, but if there is no publication in place to advise the operators of the use of unqualified staff, pilots may be under the impression that positive control is still being provided, as in the case where states have established ‘controlled aprons’. (The term unqualified personnel in this case refers to personnel not trained and licensed according to ICAO recommendations for the provision of air traffic services. ICAO Doc. 9476 states that staff be trained and licensed and their legal authority must be clearly established, but does not provide the standard recommended for training and licensing). Hence the overall responsibility for the provision of this service is at the discretion of the Aerodrome Controller and with no clear cut recommendation from ICAO, the possibility of administrative fault on the part of Aerodrome Control and consequent liability remain on the part of the authorities. In the USA the state claimed that the Federal Tort Claims Act is inapplicable since it limits the liability of the state to that which a private individual would have under ‘like’ circumstances arising from the performance of a discretionary function or duty.

However, there is comparable private liability to that relating to the operations of a controller, that the controller performs government or state functions of a regulatory nature, and that no private individual has such powers of regulation.

As seen in the British system, the British Airports Authority is duty bound to provide all its aerodromes such services and facilities as are in its opinion necessary or desirable for their operation (Act 1965), and has power to do anything which is calculated to facilitate the discharge of its duty under this Act.

Therefore it is difficult to compel this performance of this public duty at the suit of a private individual (the controller).

In major accident cases which have presented the possibility of administrative fault on the part of Aerodrome Controllers, and consequent liability remained on the part of the state, the question of ‘discretionary function’ would be dealt with as criminal liability on the part of the controller. In the scope of today’s aerodrome traffic and with the increasing volume of vehicles, Advanced Surface Movement Guidance Control Systems (ASMGCS) will be the only salvation for aerodrome control. Although accompanied by its own set of problems, it will give the controller added assurance in executing his/her duties.

Privatisation of ATC does not necessarily mean full privatisation of the service. Although IFATCA policy on Privatisation/Commercialisation (IFATCA manual page 4 1 2 3) states that “Privatisation of ATC refers to the process by which the functions and or assets of ATC are transformed from a government to either the private sector or to a company or corporation owned either partly or fully by the government, but operating independently of total government control”. There is an element of truth in this, but the function of air traffic service is likely to remain wholly a government function. The extent of any particular transfer may not have been fully explored, thus there is a need to examine the legal implications, as far as the controller is concerned, when entering into a contract with such a company.


There are limitations in the acts or statutes that exclude liability for negligence in the performance of discretionary function, therefore it involves certain standards which are intended to balance the need for facilities with the economic or physical limitation inherent in the system. It is difficult to conceive of anything more discretionary in character than the determination of where the greatest need exists for advanced equipment, planning, or review of the technology of ATC. Areas of concern being the provision of Apron Management Service by non-ATS staff or unlicensed personnel and the parameters of responsibilities outlined by the authority to safeguard the Aerodrome Controller.

There is a need for authorities to have procedures in place where surface monitoring equipment is in use, with ASMGCS separation standards implemented.

With the privatisation of ATC posing new problems in the already complex air traffic world, there is a need for ICAO to draft recommendations that are in line with the latest developments in the aviation industry, as is seen in the introduction of ASMGCS.


That this paper be accepted as Information Material.

Last Update: September 28, 2020  

March 4, 2020   486   Jean-Francois Lepage    1997    

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