Hi all, I just have several flight with my P3. Last flight I was flying in a valley where GPS signal was almost 0. Took off in P-OPTI and sometimes P-ATTI, green light flashed normally. Then suddenly the yellow light flashed, just like if you fly in ATTI Mode in P2. It's not blinking rapidly like when losing connection to controller. P3 was still flying very stable despite of yellow light. I am curious what mode is exactly that give out yellow light ? I read in manual it should be A mode that has yellow light. If I have mistakenly switch the Mode switch, it didn't show up in Flight record, all modes were P mode.