Failure Effects Evaluation for ATC Automation System

Table 2

The Classification failure incidence.

Classification	Classification basis	Examples
A	Control unit cannot provide air control service	() Backbone of communication networks of control unit failure.; () Internal phone communication system (very high frequency system) failure.; () Main and backup functional automation device overall paralysis
B	Failures decline the control capability of air control service and greatly reduce the flight capacity	() The whole or part of the automation system cannot be recovered in a short time.; () Failure of automatic transfer system.; () Partial control seats at the same time failure or other equipment failure which leads to air to ground communication failure.
C	Failures cause the degradation of service quality on monitoring communication and navigation and reduce the control efficiency	() Short time main device or automatic transfer system performance degradation leading to failure of flight plan processing function.; () Control coordination/transfer of telephone failure due to various causes.
D	Failures have no effects on flight and traffic control	() Single machine or single network of redundant system fault.; () Transient control over telephone or other equipment performance degradation and rapid recovery does not affect the control operation.