Welcome back to the debate John Purdey. To some extent we are covering old ground here, but for the benefit of the debate I am happy to go over it again.
> The answer is that the known facts show that at around waypoint
> change, the crew had four choices: slow down and think about it; climb
> to safety altitude (though I note an earlier comment that the icing
> layer was against them); turn port along the coasdt; or fly straight
> ahead.
I am pleased to see you have accepted the icing point, however I feel you mis-state the options. In reality I believe the options were:
1. Continue with the planned flight, which involved a small turn to the left and a climb to clear terrain 2. Make a larger turn left and continue up the western coast, at low level if necessary 3. Abort the mission and return to Aldergrove
There were other options, such as continuing up the eastern coast of the Mull, or climbing into IMC, but none which are likely to have been considered by the crew for reasons already covered. Continuing straight on was not a realistic option as it fitted neither the flight plan nor the alternatives. By continuing straight on they would have been going considerably off course and towards known terrain.
> or fly straight ahead. They chose the latter
Actually they turned slightly right, which does not fit any of the profiles above (either yours or mine).
> and selected a cruise climb.
The aircraft may have *achieved* a cruise climb, but we do not know what was selected.
> That rate of climb would have cleared the high ground at the
> lighthoue,
Indeed, but not by an acceptable margin in IMC
> BUT they were over 500 yards to sbd of the intended track, and the
> cruise climb did not clear that much higher terrain.
> It is precisely to accomodate any possible positional errors of that
> kind that we have a regime of safety altitudes.
Indeed. Unfortunately the Chinook HC2 was unable to climb to safety altitude due icing, which is just one of the reasons that the aircraft was unsuitable for this mission. If there is any negligence attributable, it is to the people to decreed that a Chinook HC2 should be used for this mission.
> The negligence lay in the fact that the crew pressed on in IMC when
> all the rules of good airmanship were against them doing so.
There is no evidence that they "pressed on" voluntarily
There is no evidence that they were in IMC
There is evidence that they were not in IMC
There is evidence which questions the serviceability of the aircraft at the time of the accident There is evidence of intermittent untraceable problems with many aspects of the Chinook HC2 at the time
I look forward to your thoughts on these points.