DozyWannabe:
aterpster:
That's why the chart/FMS mismatch was considered a "contributing" cause rather than a "primary" cause (most of which were variations on loss of SA on the part of the crew).
Nevertheless, the mismatch did contribute and was proven to contribute. I don't mean to sound harsh, but the fact that you feel the flight crew should have done things fundamentally differently doesn't alter the situation.
No, I don't see you as being too harsh. You and I have a different view of the facts.
The four probable causes makes it quite clear the Colombia investigators reached the same operational conclusion that I did. I have no quarrel with their probable causes. But, in the area of contributing factors I believe they were expecting more of 1995 FMS databases (i.e., be the "same" as the paper chart) than was realistic. In fact, the same circustances exist today in many, if not most FMSes: select either direct-to a downstream waypoint or VTF, and "poof" the legs page no longer resembles the paper (or electronic) chart.
Also, as discussed in the report, no doubt that "get there itis" really had this crew hooked. Nonetheless, had they been sufficiently sharp to have simply reverted to raw data, they could have been quickly back on track and had sufficient distance remaining to the airport that a speed-brake assisted descent would have gotten them down in time for a landing on Runway 19.
From the Colombian report:
3.2 Probable Cause
Aeronautica Civil determines that the probable causes of this accident were:
1. The flightcrew's failure to adequately plan and execute the approach to runway 19 at SKCL and their inadequate use of automation.
2. Failure of the flightcrew to discontinue the approach into Cali, despite numerous cues alerting them of the inadvisability of continuing the approach.
3. The lack of situational awareness of the flightcrew regarding vertical navigation, proximity to terrain, and the relative location of critical radio aids.
4. Failure of the flightcrew to revert to basic radio navigation at the time when the FMS-assisted navigation became confusing and demanded an excessive workload in a critieal phase of the flight.
3.3 Contributing Factors
Contributing to the cause of the accident were:
1. The flightcrew's ongoing efforts to expedite their approach and landing in order to avoid potential delays.
2. The flightcrew's execution of the GPWS escape maneuver while the speedbrakes remained deployed.
3. FMS logic that dropped all intermediate fixes from the display(s) in the event of execution of a direct routing.
4. FMS-generated navigational information that used a different naming convention from that published in navigational charts.