Uplinker:
I've always had a nagging feeling about RNAV approaches. We are taught to very carefully check the approaches and the tracks and distances of the waypoints in the database, and are led to believe that the coordinates are very carefully checked and verified by the database suppliers. I will certainly be checking even more carefully in future, but how can we guard against incorrect data? There is no ground based reference to double check our approach.
The fault was with the state, not the database supplier. With any RNAV procedure, particularly RNP AR, if the source state procedure designers don't do their job, then the origin of the chain is contaminated. Nonetheless, had the crew had the required visual references at DA, this would have been a non-event.
Further, if the state had robust flight inspection, as many countries do, they would have flight inspected the modified procedure and have easily caught the erroneous data provided for the "temporary" displaced threshold.
All of this was probably done by the third-party designer of the original procedure. But, they weren't there for the jury-rigging done to account for the displaced threshold.
Even today, the procedure is not in compliance with ICAO DOC 9905, because the MAP is at the threshold instead of DA.