What is a runway incursion? Incursions on to a runway happen where two or more vehicles are either on or approaching same runway, resulting in a conflicting situation. This can be defined as “An event at an airfield involving the incorrect presence of a vehicle, aircraft or person on the protected area of the surface designated for the landing and the taking off of aircraft”.
It should be noted that this may be a consequence of a failure of a pilot or vehicle driver to comply with a valid ATC clearance or their compliance with an inappropriate ATC clearance. The main consequence of any incursion is the increased risk of collision for aircraft on the ground.
According to investigations in to these types of events which occurred in the period 2014-2016, the following general observations were seen to be the most common:
- Mistaken entry of an aircraft or vehicle onto the runway protected area without ATC clearance
- misidentified presence of a vacating aircraft or vehicle onto the runway protected area
- Wrong runway crossing by an aircraft or vehicle without or against ATC instructions
- Landing without ATC clearance
- Take-off without ATC clearance
Other main factors that can increase the possibility of an incursions occurring are:
- Low visibility may increase the chance of a pilot becoming disorientated and unsure of their position whilst manoeuvring along taxiways. These conditions are also likely to restrict a ATC’s ability to identify and follow aircraft visually
- The design of the taxiway infrastructure which requires aircraft to cross an active runway to travel between its take-off or landing runway and the parking position, brings additional risk of an incident occurring.
- Line ups for a series of aircraft departures from the same runway but from different entry positions could lead to an increase the potential for runway incursion occurrence.
- late changes to Departure times and clearances may lead to a temporary lack of concentration in the pilots attentiveness.
- Use of Non-Standard Terminology can lead to confusion and misunderstanding between pilots and controllers.
- Simultaneous use of more than one Language for communications between ATC and vehicles crews.
There are ways several ways to overcome these types of situations
- Maintenance of situation awareness by flight crew and others using the manoeuvring area, specifically in respect of their own location in relation to active runways, and that of other aircraft and vehicles relative to active runways.
- Presence of standard Runway Markings and Taxiway Surface Markings and Signs
- Presence of standard Runway Lighting and Taxiway Lighting including the installation of Runway Status Lights (RWSL) and Runway Holding Point Lighting.
- The use or runway incursions control systems that monitor vehicle movement on at the entrance or exit of the protected area.