Originally Posted by
retired guy
Ok point taken and apologies for missing your well made argument.
R Guy
No problem. We're all just trying to sort out a truly complex and confusing situation.
FYI, here's the relevant finding re: inadequate documentation, item 6 of Dekker's findings and conclusions:
Based on their training and documentation, the TK1951 crew would have believed that they had protected their aircraft and its flight from any pre-existing problems with the left RA. The right autopilot (known as Autopilot B or CMD B) had been selected on, and the right Flight Control Computer (known as FCC B) was giving it inputs.
Boeing pilot training materials and documentation do not reveal that the autothrottle always gets its height information from the left Radio Altimeter, that, on pre-2005 737NG models, it doesn’t cross-check its RA input data with other RA data; and that the right RA does not provide input to the autothrottle—even when FCC B has been selected as Master and Autopilot B is flying (which was the case for TK1951).