It depends.
Skybrary says
The Runway Excursion category includes also two types of occurrences which do not fit the ICAO ADREP definition for a runway excursion, however considered appropriate for inclusion due to the commonality of a number of causal and contributory factors and/or mitigation approaches:
- An aircraft attempting a landing touches down in the undershoot area of the designated landing runway within the aerodrome perimeter.
- A runway or taxiway other than the designated one is used for a take off or a landing.
My emphasis.
The European Commercial Aviation Safety Team (ECAST) in the European Strategic Safety Initiative (ESSI) use the Skybrary definition when writing about Runway Excursion Prevention
Articles within the Runway Excursion Category in SKYbrary:
- Overrun on Take Off
- Overrun on Landing
- Directional Control
- Undershoot on Landing
- Wrong Runway
My emphasis.
In an article "Language and safety issues" in Eurocontrol's magazine in 2011, Bert Ruitenberg wrote:
The whole idea of putting a label such as “runway incursion” or
“runway excursion” on a safety occurrence is to make it easier to
file the data from the event somewhere and to compare it with
similar occurrences. With the definitions above, a take off from a
taxiway would be considered as a Runway Excursion when the
Skybrary definition is used, but not with the other RE definitions
(and rightly so, I say, better label it a “taxiway take off”). Moreover,
in the ICAO definition, the B777 undershoot at Heathrow
would not be a RE, but with the Skybrary definition it would be.
Dear Safety Managers of the world, there still is a lot of work to
be done...