Couple of uses for ATTI mode

[Fred_C_Dobbs]

In addition to allowing a bit smoother video due to turning off the constant GPS control inputs, I have found 2 more uses for ATTI mode.

1. If you are planning to fly a long distance and want to better ensure you have enough battery to get back from the turn around (or control signal loss) point then try this procedure. After she is ready to fly (I almost always fly in GPS mode), take her up to the altitude you will be flying at and put her in ATTI mode for a few seconds. Observe the direction and speed of drift (if any) and this will give you an excellent idea of the general wind direction and speed at that altitude, which could be significantly different than want you are experiencing on the ground and keep you from inadvertently flying with the wind on the way out and fighting it on the way back.

2. When descending from a high altitude, put her in ATTI mode and she will generally take care of the lateral movement on her own, thus making the turbulent air problem less likely.

 

[John Shaw]

2. When descending from a high altitude, put her in ATTI mode and she will generally take care of the lateral movement on her own, thus making the turbulent air problem less likely.

I am concerned this could be a false perception. If you have commanded a straight descent in ATTI the Phantom is descending directly into it's own downwash but because the air mass is moving laterally it appears the Phantom is moving laterally thereby evading it's downwash - but it isn't. If you could see the downwash you would see it stays with the Phantom.
On the other hand if there is a breeze and you descend in GPS mode the Phantom will hold it's position over the earth and the downwash will move out from under it with the air mass. Of course no wind this isn't true.
Or is there some other dynamic you've observed?

Fred - I agree this is an interesting list to develop - I'll keep watching.

 

[Fred_C_Dobbs]

John, you make an excellent point which I had not considered. I guess I was assuming that even when the Phantom is drifting with the wind, there would still be some relative wind speed, but it would indeed be diminished. The Phantom would be, in effect, chasing it's downwash instead of moving away from it or letting the wind blow it away. So, I would tend to agree that if the wind is kicking up, it's probably safer to descend in GPS mode, or if you are in ATTI mode, keep her moving into the wind rather than let her drift with it.
\\FCD\\

 

[general01]

i have used the atti mode to check wind direction in a pinch before(also have a whether unit that shows wind direction)

 

[Dillinger]

Good thread!
We were parasailing and upper winds were unclear - we launched phantom and in ATTI mode You can see even speed in m/sek on app.
Altitude and speed will be visible and its good.
However for me it seemed showing little less speed than I expected.

 

[John Shaw]

Good thread!
We were parasailing and upper winds were unclear - we launched phantom and in ATTI mode You can see even speed in m/sek on app.
Altitude and speed will be visible and its good.
However for me it seemed showing little less speed than I expected.

WOW!! That's a great use that is sort of "out of the box thinking". A use totally different from the intended use.

 

[general01]

One tip to anyone who uses it in atti mode like this for the first time make sure your not near any trees or it won't be as effective(trees cut the wind speed)