THE PROBLEM OF RUNWAY INCURSIONS continues to pose a challenge to the safety of airport operations. More than 3,500 replies from pilots and air traffic controllers to a questionnaire issued by Eurocontrol in 2001 cited this as the most serious threat that needs to be dealt with by the airport community.
It is a difficult problem. Often multiple contributory factors can lead to an incursion. Due to the sensitivity of these types of incidents, it has proven extremely difficult to collect detailed data on incursions in Europe. As a result, determining trends or failure hot spots has not been easy.
However, in 2001 Eurocontrol, in conjunction with the International Civil Aviation Organization (ICAO) and the Joint Airworthiness Authorities (JAA), commenced an initiative to determine the frequency and severity of the runway incursion problem. It rapidly became obvious that this was, indeed, a severe threat, a fact strongly underlined by the Milan runway collision that occurred a few months after the initiative was started. This incident occurred Oct. 8, 2001, at Linate Airport, between an SAS MD-87 and a Cessna Citation business jet.
It became apparent that the problems faced by pilots, controllers and vehicle drivers were significant when involved with operations on complex, high-traffic-intensity airports. It also was recognized that pilots often were faced with inadequate or confusing signs and markings, non-standard procedures, and non-ICAO phraseology. Likewise, controllers often must face the task of dealing with high volumes of traffic, with correspondingly high workloads. They must balance the task of maintaining capacity while preserving the highest levels of safety.
In recognition of this, Eurocontrol formed a multidisciplinary Runway Safety Working Group in an attempt to resolve the runway incursion problem. The group consisted of pilots and controllers, airport operators and national safety regulators. The International Federation of Air Line Pilots Associations (IFALPA) and International Federation of Air Traffic Controllers’ Associations (IFATCA) provided considerable expert input to the group’s workings. Both supplied information on the difficult pressures experienced by pilots and controllers.
Following an intensive period of data collection, a European Action Plan for the Prevention of Runway Incursion was produced. This action plan contained about 50 recommendations, targeted mainly at pilots, controllers and vehicle drivers. The prime aim was to improve the standard of communications, the breakdown of which frequently has led to an incursion. Another area addressed was the consistent application of ICAO standards, which could increase predictability and reduce the possibility of misunderstandings for pilots.
While this action plan has been successful within the European region, it has been recognized that other regional action plans exist, such as one produced by the U.S. Federal Aviation Administration (FAA). A small number of differences exist between these action plans, but the differences have the potential to significantly impact safety, as aircraft fly from region to region.
During 2004 work is taking place to produce a global and totally harmonized action plan under ICAO’s auspices. This project, if successful, will significantly improve the level of safety for runway operations.
Parallel with this is an awareness of the technologies behind the many different types of safety nets, or warning devices, being developed by industry to prevent incursions. In general there are two main areas of development: those that provide situational guidance to pilots and those that provide an alert when a dangerous situation develops.
Both have the potential to enhance the safety of runway operations. But both have drawbacks, as well, which need to be addressed. For the devices that give positioning information to pilots and are intended to prevent blunders onto a runway, an important issue is that, for about 50 percent of incursions, pilots know exactly where they are. The problem is due to a breakdown in communications because they believe they are in possession of a valid air traffic control (ATC) clearance to enter the runway. For the collision avoidance devices, the issue is that the time from when an aircraft crosses the stop bar to when it enters a runway can be just a few seconds. Clearly this small amount of time will present a challenge to the development of any effective warning device.
While the problem of runway incursions remains a serious threat, it now is a high-profile issue. Awareness is high. Although it is impossible to state how many incursions have been prevented by the Eurocontrol joint initiative, without doubt significant progress has been made towards solving this most complex and difficult problem.
Paul Wilson is head of Eurocontrol’s Airport Throughput Business Division.