This is a terrific discussion for people like me, newly typed in the NG at this late stage of life (don’t get me started…). I really like the airplane, brings back enough 727 memories to last me and is so antithetical to the Airbus that I am practically gleeful. However, our training department, as is the case in many settings, lives in a stovepipe, enjoying life without the slightest notion of how any airplanes actually work other than their own. For us more senior, less flexible types, coming off years of 767/757/MD80 operations, the nuance of the 737 has been challenging. Wouldn’t hurt if the manuals were slightly more informative, but maybe that’s just me…
I started out getting chastised for pickling off the A/T at 100 feet…”we don’t do that…” “Do what?” “Disengage the autothrottle…” “What? Why?” “We just don’t…”
We had a bit of discussion about the “technique” of deselecting speed and leaving the autothrottle in ARM. As others have pointed out, this is frowned upon. Interestingly enough, if I understand it correctly, that is exactly what will happen at VNAV disconnect, which will occur at the end of the approach. This could be some distance from the runway. In any event, VNAV disconnect will leave the A/T in the ARM mode exactly as would deselecting the speed mode. I think.
If I’ve got this right, not only does the A/T arm mode give you alpha floor protection, but it also is armed for go-around (below 2000 feet, etc., etc.) Hence the wonderful ability to get autothrust during the FD-only go-around following the VNAV disconnect with no runway in sight.
The only drawback I could see to deselecting speed mode is that one has to reach up and push the correct button without smashing your cheek on the HUD combiner while peering around trying to find said button. On the other hand, as I was told I would, I’m not sure I see any real advantage over just leaving the A/T active and manually overriding it as needed.
RAT 5, "who ever thought that using the flap lever to drive the speed bug on GA was good idea. Duh!" is the best explanation of that gimmick that I've heard. Apparently I was supposed to figure that out by osmosis.
