Originally Posted by
galaxy flyer
There's just something wrong about "coupled approach" and "visual". Do we know when the crew disconnected the autopilot, or more accurately, are we sure it was hand flown from earlier in the approach? I know what your saying, but at some point a visual is a hand flown maneuver.
If you go back through this thread (yeah, right) someone who currently operates into KSFO and who has used this FMS 28R database visual approach stated how nicely the airplane flies the approach, with auto-throttles.
I have the source. It aligns with the Runway at FD101, or about 3.6 miles from the threshold, and on a 3.0 degree VNAV path. Jeppesen codes these types of FMS database visuals to switch from terminal to LNAV/VNAV approach sensitivity (RNP 1.0 to RNP 0.30) at what Jeppesen considers to be the "FAF."
So, when are you supposed to disconnect? I don't know. I hope the carriers provide some type of training for commercial crews to use this non-public FMS visual procedure.
So far as where the visual segment begins, that would have to be at the point the clearance for the visual is issued. And, how close in should this procedure be disconnected from autoflight? 500 feet?
We don't know whether AC was coupled to the procedure.
What concerns me beyond this incident is that at least some portion of this procedure is being flown in IMC as a de facto instrument approach. I suppose the vertical path is above the applicable ATC MVAs until 1,600, which is the lowest MVA over the water east of 28L/R.