Third Party Risk

Third Party Risk

42ND ANNUAL CONFERENCE, Buenos Aires, Argentina, 17-21 March 2003

WP No. 95

Third Party Risk

Presented by SC1


1.1  The ATM system is more often becoming a very securely monitored system by politicians and by the people living close to an airport. The feeling of being safe when living close to an airport is influenced by the number of flights that can be heard and/or seen, and the growth of Air Traffic will have an adverse effect on this feeling.

1.2  This paper is to introduce the term “Third Part Risk” (3PR), and describe the impact of it on ATC.


2.1  In 1992, an El Al flight flew over Amsterdam city-centre and other densely populated areas, after declaring an emergency. The flight eventually crashed into an apartment building. One of the recommendations in the accident report was:

“Expand the training of pilots and ATC personnel to include the awareness that in the handling of emergency situations not only the safety of aeroplane/passengers, but also the risk to third parties, especially residential areas, should be considered”.

At a later stage, a parliamentary commission reviewed the role and actions of all persons involved. One of the recommendations of this committee was:

“The commission has the opinion that it is recommended to include emergencies in the consideration of external safety. Further possibilities for concrete filling in of the recommendation of the accident report with respect to external safety must be investigated. Considerations could be focussed in particular on presentation of populated areas on air traffic controllers’ radar displays during emergencies”.

2.2  Third party risk is the probability that individuals die, as a consequence of an aircraft accident in the area around, but outside, the demarcation of the airport.

2.3  In the development in the Netherlands of special procedures for controllers to handle aircraft in an emergency situation, two different classifications of emergencies have been identified:

  • Immediate landing required; and
  • Time permitting or not time critical.

These classifications are solely based on the judgement by the pilot declaring the emergency, since only the pilot can judge the seriousness of the situation. ‘Immediate landing required’ is a situation whereby the pilot would want to land at the nearest suitable airport. On the other hand, ‘time permitting’ is a situation where the pilot has got time available for example to try to solve the problem or dump fuel before performing an approach and landing. The fact that emergencies classified as ‘immediate landing required’ are left out of consideration is the basis of the procedures that are being developed. If a degradation of the situation from ‘time permitting’ to ‘immediate landing required’ would take place, all special emergency procedures would no longer apply to that specific situation. Based on the emergency classifications mentioned above, two possible procedures have been identified, both should be considered separately:

  • Landing runway suggestion considering third party risk; and
  • Route suggestion considering third party risk, e.g. display of populated areas, display of emergency corridors and best practices.

NOTE: Best practises elaborate on the knowledge, experience and skills developed during the initial and recurrent training of controllers and is based on the EUROCONTROL ASSIST principle.

The different route suggestions considering third party risk as described above will not be further considered in this paper, since the procedures are still under development and no choice has been made from the different architecture options. The ranking on landing runways is based on the degree of population in the (final) approach of that specific runway.

2.4  In the United Kingdom, there are also special procedures that should be applied when an aircraft in an emergency situation has the intention to return to an airport. According to the procedures of the RAF Distress and Diversion (D&D) Cells, it is desirable that aircraft in emergency shall not be routed over densely populated areas. The procedures state:

“Where, possible, when expeditious routing is not required, suggestions of alternative runways or aerodromes together with the rationale that the routing would avoid densely populated areas and be consistent with safety, shall be passed to the pilot and his intentions requested”.

These procedures clearly show that in a stressful situation, extra actions are required from both the controller and the pilot. The procedures also state that controllers that provide aerodrome, approach or approach radar control services should be familiar with the centres of population within their areas of jurisdiction. The D&D procedures clearly state that the ultimate responsibility in accepting a diversion from the, by the pilot selected, route lies with the captain of the aircraft who has ultimate responsibility for the safety of his or her aircraft.

2.5  ICAO PANS ATM (Doc. 4444) states:

“The various circumstances surrounding each emergency situation preclude the establishment of exact detailed procedures to be followed. The procedures outlined herein are intended as general guide to air traffic personnel. Air traffic control units shall use their best judgement in handling emergency situations”.

All guidance in PANS ATM is very generic and places ATC personnel in a supporting role. When it comes to manoeuvring instructions, it is stated that:

“Manoeuvring instructions to an aircraft experiencing engine failure should be limited to a minimum”.


3.1  Besides the procedures in the United Kingdom and the Netherlands, no other national emergency procedure could be found that should be addressed in this paper. However, based on the procedures in the countries mentioned and the increasing feeling of being unsafe of both politicians and people living close to an airport, it is very likely that special emergency procedures will be introduced at a larger scale in the future.

3.2  The standard operating procedure for handling aircraft in an emergency situation, which may have taken an aircraft over populated areas, will be or has been changed in the instances above. In all occasions, the controller and the pilot will both endeavour to remain clear of densely populated areas. Any expansion on this procedure, e.g. special emergency procedures, should be introduced with the appropriate training.

3.3  There is a clear need for a harmonious approach of Air Traffic and populated areas around airports.

3.4  The legal liability of all parties involved, i.e. Airport authorities, ATC service providers, local authorities, pilots and controllers, must be clear.


It is recommended that:

4.1 This paper be accepted as information material.

Last Update: September 29, 2020  

March 22, 2020   583   Jean-Francois Lepage    2003    

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