I think there may be one surprise. In December, the NTSB posted to the docket the data extracted from the Flight Management System (I only noticed it yesterday). I am not a pilot or aviation professional, but I noted some anomalies:
1) When the FMS was powered on at LGB the day of the crash, its last known position was at the IEX helipad on Catalina Island. Can someone more knowledgeable about FMS operations explain to me how that is possible? Do you have to turn on the FMS separately, or is it normally powered on by switching on the avionics power bus?
2) The NTSB notes: "When the FMS is initialized, it will default to the position stored when power was previously removed or the GPS position, if it is available. This position is presented to the crew on the FMS initialization page, where the crew can accept it, or manually change it before accepting it. Should the crew accept a Reference Position that is significantly different from the actual aircraft position, the FMS will annunciate position uncertain and post difference warning messages after GPS position becomes available. Over time, the Reference Position would converge to true position by using DME and GPS.
3) There are unseen (by the pilot) warning messages in the FMS: "GPS 1 DIFFERENCE 6 NM" "REFPOS and GPSPOS > 6.0 NM". "DEAD RECKONING MODE"
4) When the pilot selects DTO (Direct To) KCMA, the FMS records a present position (PPOS) not on the flight path (this is recorded in the NAV Leg Editing Buffer). I am wondering if the FMS has not yet converged to true position.
5) The CDU at the time of the crash appears to me to be showing errant data (Figure 4-1 in the report). I think it is saying the distance to the destination is closer that it actually is and that the bearing between the displayed PPOS and Destination is incorrect. It would be fantastic if someone with more experience with the UNS FMS can confirm.
If I am interpreting the information correctly, it seems that the above would have added to the pilot confusion and workload. Here is a link to the docket entry:
https://data.ntsb.gov/Docket/Documen...edRev2-Rel.pdf