To bring the U.S. in line with the international definitions of runway incursions, the FAA has adopted the ICAO standards, effective immediately. The biggest difference between the two definitions is that ICAO defines a runway incursion as any unauthorized intrusion onto a runway, regardless of whether an aircraft presents a potential conflict.
In the FAA’s terminology, an incident without an aircraft in potential conflict–such as an unauthorized aircraft crossing an empty runway–was defined as a “surface incident” rather than a runway incursion. The new definition means that some incidents formerly classified as surface incidents will now be classified as C or D category runway incursions, low-risk incidents with ample time and/or distance to avoid a collision. The classification of the most serious kinds of runway incursions–A and B–remains unchanged.
The FAA is making the change so the worldwide aviation community will have a single runway incursion definition, which in turn could help determine common factors that contribute to these incidents.
The FAA helped ICAO create its definition, which was adopted in November 2005. Before that, countries around the world used at least 20 different definitions for a runway incursion.
The FAA has always tracked surface incidents, in addition to runway incursions. The new definition simply means that certain less severe incidents will be classified differently. All incidents tracked in the past continue to be tracked.
According to the FAA, the total number of category A and B incursions has fallen from 53 in Fiscal Year 2001 to 31 in FY2006. A and B incursions are on track for another drop in FY2007, with 24 recorded through September 9. The fiscal year ended September 30.