RUNWAY INCURSION
ICAO defines Runway Incursion as “any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle or person on the protected area of a surface designated for the landing and take off of aircraft.” It is simply a wrong positioning of aircraft, vehicle or person on a runway or its protected area (safety area immediately surrounding the runway around the shoulders and end of the runway).
Types of Runway Incursion
Data from investigation of incursion induced accidents and incidents over a certain period has shown the following generic types of runway incursions to be common:
- Incorrect entry of an aircraft or vehicle onto the runway protected area (without or contrary to ATC clearance or due to incorrect ATC clearance).
- Incorrect presence of a vacating aircraft or vehicle onto the runway protected area.
- Incorrect runway crossing by an aircraft or vehicle (without or contrary to ATC clearance or due to incorrect ATC clearance).
- Incorrect spacing between successive arriving or arriving and departing or departing and arriving aircraft.
- Landing without ATC Clearance.
- Take-off without ATC Clearance.
Contributing Factors
There is a wide range of factors which contribute to the occurrence of runway incursions. These factors can be grouped as follows:
- Pilot Factors: Mostly from inadvertent non-compliance with ATC clearances, either because of breakdown in communication or loss of situational awareness.
- Air Traffic Control Factors: Here, momentary loss of concentration or focus and communication errors are found to be predominant.
- Airside Vehicle Driver Factors: Include communication errors, failure to obtain clearance from ATC or to comply with same, inadequate training on airside driving, etc.
- Aerodrome Design Factors: Complex or inadequate aerodrome design increases chances of runway incursion.
RUNWAY EXCURSION
ICAO defines Runway Excursion as “a veer off or overrun off the runway surface. Simply put, it is an incident where an aircraft makes an abnormal or inappropriate exit from the runway.” Runway excursions can occur on takeoff or on landing, as well as during taxi. They may be intentional or unintentional.
Runway excursions consists of two types of events: Veer-Off (excursion in which an aircraft departs the physical edges of a runway or taxiway); and Overrun (excursion in which an aircraft departs the end of a runway). A further categorization of these two types of events are as follows:
- Overrun on Take-Off: A departing aircraft fails to become airborne or successfully reject the take-off before reaching the end of the runway.
- Overrun on Landing: A landing aircraft is unable to stop before the end of the runway is reached.
- Veer Off: An aircraft departs the side of the runway after touchdown on landing or departs the side of the runway during line-up or take-off run.
Contributing Factors
Factors that contribute to the occurrence of runway excursion include, but are not limited to:
– Weather
– Inadequate or lack of signages and markings.
– Insufficient knowledge of the airfield
– Faulty or malfunctioning equipment
REFERENCES
ICAO Doc 4444
ICAO Doc 9870
Wikipedia
