If this is a rehash, I apologize in advance.

So...  Vision Plus V3.  Been flying a couple of weeks.

I have a nice valley on my property.  About 1000 ft across, 200 feet deep.  I'd like to fly down into it.

I start flying from the ground above the valley.  Rise to 30m altitude and fly out level over the valley.  The altitude on the app reports the bird is still at 30m altitude.

OK.  The altitude is relative to the starting position.  I can understand that.

So, what happens if I drop into the valley below my starting altitude?

Does the Phantom think it's hovering below the ground and shut down?

Thanks in advance.  Learned a lot from the group.

Cheers!

It will just show a negative altitude on the display.

Thanks Gerry1124.

So, there's no functional oddness to be concerned about?

I'm guessing plenty of people stand on a bridge and fly underneath themselves without thinking about it.  When I tried to work out how the thing deals with landing, RTH, etc, I just got more confused.

I'll try dipping into the valley soon and gain some confidence in the algorithms.

Thanks again.

Cheers!

CryoEng Posted at 2015-4-4 07:27
Thanks Gerry1124.

So, there's no functional oddness to be concerned about?

If it went into return to Home, and you had 100 feet as an RTH altitude set, and you are at a -150 feet, it would come up to the 0' altitude mark and keep going to the +100 foot altitude.  It always measures from the point of takeoff.

I've been wondering the same thing, as I have a quarry I'm interested in flying over and down into it

trsmith18@hotma Posted at 2015-4-4 10:44
I've been wondering the same thing, as I have a quarry I'm interested in flying over and down into i ...

As long as you can remain in direct line of sight so your control signal will get to the Phantom, you won't have any problem.

Thanks everyone!

This is too much fun!

Cheers!

The only issue I can see arising, may be when the battery gets extremely low and its forced to "auto land"  How does the phantom know when its on the ground???

So if you set you homepoint up on a cliff and are flying down into a valley or grand canyon (for example) when the battery gets extremely low and the altimeter is reading zero or negative won't the motors just cut out because it thinks its on the ground?

trsmith18@hotma Posted at 2015-4-5 03:54
The only issue I can see arising, may be when the battery gets extremely low and its forced to "auto ...

I'm pretty sure I'm correct in saying that it will *never* cut the motors if it 'thinks' it's still moving. This is why CSC shutdown can't be activated when in flight for example.

I guess it's all a question of confidence/monitoring your situation...... If I was down a few hundred feet in a canyon, I know I'd get her back close to me long before the battery goes 'critical'.... ;)

Cheers,
Ian

i_anderson@iclo Posted at 2015-4-5 04:01
I'm pretty sure I'm correct in saying that it will *never* cut the motors if it 'thinks' it's still ...

agree with what you said...with the exception of the fact that you most certainly CAN CSC and kill the motors mid-flight

trsmith18@hotma Posted at 2015-4-5 03:54
The only issue I can see arising, may be when the battery gets extremely low and its forced to "auto ...

When it no longer detects a change in altitude for three seconds at which point the rotors stop.  Just like normal.

trsmith18@hotma Posted at 2015-4-5 04:19
agree with what you said...with the exception of the fact that you most certainly CAN CSC and kill ...

Wow!...... Thanks for that.

I certainly haven't tried it - glad I haven't now! - I thought I read somewhere it would 'ignore' a CSC as long as it believes it's still moving.

Cheers,
Ian

trsmith18@hotma Posted at 2015-4-5 03:54
The only issue I can see arising, may be when the battery gets extremely low and its forced to "auto ...

Your Phantom will not turn off unless 1, your battery completely dies or, 2. your Phantom has stopped it's descent for 2 to 3 seconds.as long as it is still moving whether negative or positive altitude, it will keep running.

My house sits 80 feet above the floor of Hooper Holler*.  Never had a problem flying down into it when I was scouting for any revenooer agents lookin' to bust up my moonshine still.

(* For the non-Kentuckians a "hollow" or colloquially "holler" is another name for valley)