What is "OPPTI" mode?

[Xenomorph]

Quick question. I just hooked up the P4 inside my house to play around with the settings, and I know it wouldn't be connected to GPS. Anyway it kept switching back and forth on the display from going into ATTI mode to OPPTI mode? What's that mean? I don't remember reading about an OPPTI mode?

 

[Philltayl]

OPPTI mode is when it is using its optical sensors to avoid collision with obstacles

 

[Xenomorph]

OPPTI mode is when it is using its optical sensors to avoid collision with obstacles

Oh ok, that totally makes sense. Thanks! I had no idea that it shows up as an actual flying mode.