User Abort Count
The user aborts count is a part of the general performance measures gathered as a part of the performance statistics. It provides a count of the number of User Aborts experienced as a percentage of the CPDLC sessions conducted. Two trend graphs are also shown for User Aborts: one excluding UAs that have a reason 'commanded-termination' or 'current-data-authority-abort' and a second showing the User Aborts that have a 'commanded termination' reason.
Commanded termination and current-data-authority-aborts are omitted from the first graph as neither are considered to be of direct interest in monitoring the technical system performance. UAs with reason code 'commanded termination' are caused by the flight crew terminating CPDLC so do not really represent any kind of abnormal system behaviour, and the 'current-data-authority-abort' reason code is used for 'forwarding' a user abort to the next data authority which has been asserted for the current data authority and so a particulra problem resulting in a user abort could result in two users aborts being counted if the user abort occurs when the aircraft has a connection with the NDA at the time.