Singapore AAIB Report - B777-300ER Loss of Separation Incident (Houston)

[peekay4]

Per the last paragraph on page 7 of the report, there is ALWAYS an altitude restriction or top altitude in the SID when this phraseology is used.

The question we should be asking is, "how can we prevent or catch this type of mistake in the future?"

E.g., SQ vows to implement better training and procedures, but what about other flight crews? How do we ensure that the new training and procedures are 100% effective and always complied with?

Currently when there is a Top Altitude, the initial altitude is optional in the clearance phraseology. Simply including this altitude and verifying correct read back from the pilots solves this problem.

Besides, specifying the initial altitude is already mandatory in other situations. Currently:

1. If there is a Top Altitude, then the initial altitude is optional, and the phraseology is "climb via SID"
2. If there is no Top Altitude, then the controller will assign an initial altitude, and the phraseology is "climb via SID, maintain (altitude)"
3. If there is a Top Altitude, but a different altitude needs to be assigned, the phraseology becomes "climb via SID, except maintain (altitude)"

To me, always specifying the initial altitude makes the "climb via" procedure more consistent and safe, with very little extra effort from both controller and crew.