On occasion I will see either a plane or helicopters that appear to be below the 400ft altitude mark. You know since you have been flying your P3 you have a better idea what altitude height levels are just by looking in some cases. A week or so ago I was making some test flights near my usual fly area. I could hear a plane off in the not too far distance as it was getting louder. I walked around to the side of the house and I was finally able to see the plane. Right away my 1st thought was this plane is going down. Nobody flies this low. Then I realized I needed to try and catch this on video using the P3 and being a little shook up I did my best to get it in view as soon as I could. So there my aircraft was at 190ft, you can see the plane was maybe 90ft higher. One of the neighbors said he also saw it and said it looked like someone was trying to fly below the radar. Anyway, I did manage to get a little of it on video.