DECEA Response/TCU-audit rebuttal by the DECEA
p. 56-57, related to Finding VIII:
DECEA analysis – This item has already been evaluated technically and operationally and it was considered that it would bring more operational losses than any possibility of gain, going against the world-wide tendency toward ever greater automating of information to make the controller's life easier. Therefore, its implementation is not pertinent. We suggest that the text be removed from the report.
Audit team's analysis:
24. Decea argues that the X-4000 system's automatic change of flight level functionality has always existed and that its purpose is to advice the controller ahead of time that aircraft will realize flight level changes. It further alleges that this modification was authorized in the flight plan analysis and that the controller should accompany the flight level change or authorize another procedure.
25. However, all the controllers interviewed affirmed that they do not agree with the automatic change of flight level without the controller's acquiescence. They said that the ideal would be for the system to indicate that the plan foresees a change of flight level, alert the controller that the aircraft is flying at a level different that foreseen for that leg and, if there is a loss of radar contact, maintain the last information on the aircraft's real flight level. According to the controllers, the change in level should be done via the operator's intervention, if it really occurs as foreseen, which would eliminate the display of an incorrect level.
26. In this manner, the revision of functionality proposed seeks to meet the controllers' needs and is not against their being advised of the foreseen change in flight level. What is intended is to meet the users' manifest wish to avoid having the system make the change automatically without the controllers' intervention. At no time did the audit team propose the removal of the functionality.
27. In a meeting realized in the editor's office, the managers alleged that they have not made this change because they fear that doing so could be used in the courts, since the controllers involved in the Gol 1907 accident used, as a line of defense in the trial on the case, the thesis that his functionality had been one of the causes of the accident. However, as the audit confined itself to merely technical aspects and concerned itself only in contributing to the improvement of flight safety, these aspects are beyond the scope of the audit and were not considered. Therefore, as Decea's allegations do not take into account the opinion of the controllers, who are the system's principal users, they should be considered to not proceed. As to the determination, as it deals with a polemic theme, it could be converted into a recommendation.