Chinook - Still Hitting Back 3 (Merged)

[Robin Clark]

New Look?

I have spent the day going through the forum and found some useful information.........mainly from the analysis of the Racal nav box ....but to put my observations in chronological order...........

# According to the track of the a/c , it would never have passed within 1.5 kilometers of the yachtsman , if the position he gave was accurate.....and so he would have quite a false impression of its speed . In his defence he did say that he was not familiar with the a/c type and asked to observe one at various distances in order to make his estimates more accurate..it seems this was never actioned .
# The approach to the coastline was at a very oblique angle and not head on as many contributors seem to suggest .
#The waypoint change was made 1.5 kilometers from waypoint 'A' and some 25 seconds before impact....
#The rising ground would be on the starboard side of the a/c and I imagine it is quite possible that the sea surface was still visible out to port (west) , does this mean it was still legal VFR..???..
#Both latitude and longitude entries for the waypoint 'A' in the superTANS had been rounded down , which unfortunately places the waypoint inland about 0.05 NM...
#The superTANS is stated to have been in GPS mode , I am guessing here that this means that it is only accepting/displaying data from the GPS source ....
#Analysis of the GPS position logged after impact shows that there was an offset to the SW of the actual position ......I take this to infer that the information presented to the flight crew would direct them to places North and East of the real location....
#The accumulated error of these two offsets places the waypoint 'A' inland even further , actually close to 500 meters from the shore , and coinciding very closely to the point of impact . Not a coincidence I think .
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If the offset's had been in the opposite sense the virtual waypoint 'A' would have been safely offshore....and overflying the point would have been quite safe......and the a/c could fly along the coast with scarcely any change in course.
On a good CAVOK day they would not need this waypoint as the coastline and lighthouse would be visible , it must have been entered with some intention to use it as and when.........
One final point , the magnetic variation applied for the course to waypoint 'B' seems to have a value of 9.4 degrees applied , whereas the entries made manually state 7.5 degrees ..??????..irrelevant..???
Most of this is derived from a scale drawing on a map......

waiting now for the flak........