I decided I could use the Inspire to confirm whether the crown on the chimney was cracked or not. In the process I clipped one of the attached antenna and clipped a blade.  It's all on the video.

When I took off, the Inspire was very controlled. I was in a small back yard next to a pool so I was careful when I lifed off. Everything was fine. So I increased the throttle to ascend. The chimney that I wanted to check has two antennas (neither are functioning) one of which is kind of a mesh and sticks above the chimney. I knew I was going to have to negotiate carefully.  As I got above the antenna and chimney I faced the camera down. I was controlling the bird visually and on video to make sure that I was staying high enough but close enough to get the detail I needed.

I moved over the chimney. As I did, it became more difficult to hold position. I assumed this was a combination of prop wash off the slanted roof top and possibly some effect from the downlooking sensors (since the chimney would appear to be "the ground"). I ran the video. It kept feeling like I was fighting to keep its altitude. At one point as I was correcting to come back over the mesh antenna, the copter descended. In the process, one of the props clipped the antenna. I immediately throttled for altitude. I expected that I would lose controlled, but was surprised that it continued to fly pretty well. So I calmly backed it away from the house and descended to land.

All that happerned was that I took the very tip off one of the props.  Pretty relieved that eveything went as well as it did.

I'm reminded of a saying my father had about cars...they just aren't designed to touch things!  But all in all, the copter did pretty well.

If you have any thoughts why it became more difficult to control over the chimney, I'm interested.  I'm hungry to learn as much about this machine as possible.  In retrospect, it might have been more strategic to come in from the side with the antenna to the side rather than coming over the top of it, but maybe it wouldn't have mattered much since she was moving in all directions.

http://youtu.be/dSoKBEuPMGc

What mode were you fling in?

Blackman I'm glad you got her back in one piece. I can see from the video that the area was very tight (two antennas) to hover in. IMHO I would have taken it up slightly higher and out of harms way. You could have just taken still images of the whole area at that point if you were just looking to inspect the chimney area for damage. Once landed you could have then looked at the stills on your computer and zoomed in for a closer look once you had downloaded the images .

My guess would be some turbulent airflow over the roofs.   Perhaps it's some kind of wind shadow effect that the Inspire was trying to fight.  

Another possibility that always seem happen to me is losing GPS near structures either from lack of signal or compass error, but not sure if that's your case or not.

Appreciate the input.

I was in P-GPS lock. No loss that I noticed, but I was pretty busy.

Taking stills from higher up and zooming in afterwards is a good point. My original intention was to get stills as well, but I was too busy holding position so I couldn't. But at a higher elevation, she might have settled down a bit to make that possible.