As one does scrolling through the mountains of info available in the BIG PDF I came across this perhaps overlooked item.
Semper Lightning: F-35 Flight Control System Part 1 09 Dec 2015 Dan “Dog” Canin
Source:
Semper Lightning: F-35 Flight Control System | Code One Magazine
“...the CV airplane has three different approach modes, easily selected using buttons on the stick and throttle. Two of these modes – APC and DFP – are auto-throttle modes, indicated by a three-letter label on the left side of the HUD. The third mode – manual throttle – is indicated by the absence of a label…
arguably not the most compelling indication that you’re responsible for the throttle. This interface will probably evolve; in the meantime, we need to be disciplined and to make doubly sure we’ve got APC engaged be-fore we turn throttle control over to George....
...APC is “approach power compensation” mode, in which the throttle is automatically control-led to maintain the desired AOA during approach. In the C-model, engagement of APC also increases the gain on IDLC (integrated direct lift control), which schedules the flaps in response to stick movements to give very high-gain glideslope response. Another approach mode, DFP (delta flight path), currently in the C-model only, changes the pitch axis CLAW from a pitch-rate system to a glideslope-command system. DFP improves glideslope tracking performance & significantly reduces workload during carrier approaches....”