DJI-Ken or DJI-Dave,

What is the maximum vertical and horizontal speed of the P4 with GPS, obstacle avoidance and object tracking all turned ON?

It's called P mode. For P mode, the max ascending speed is 5m/s, descending speed is 3m/s, horizontal speed is 10m/s.

DJI-Amy Posted at 2016-3-4 04:17
It's called P mode. For P mode, the max ascending speed is 5m/s, descending speed is 3m/s, horizonta ...

Thanks, Amy.  So, in P mode, the maximum horizontal velocity is 10 m/s = 22 mph.

david.p.mann@ea Posted at 2016-3-5 11:33
Thanks, Amy.  So, in P mode, the maximum horizontal velocity is 10 m/s = 22 mph.

Yes. For sport mode, the maximum horizontal speed can be 20m/s.

And to add to that, it's 16m/s (35mph) in ATTI mode.

DJI-Ken Posted at 2016-3-5 15:33
And to add to that, it's 16m/s (35mph) in ATTI mode.

I assume that GPS position hold is NOT available in ATTI mode on the P4, just like it was not available on the P3. Is that correct?

It may seem like a stupid question, but is GPS position hold available in SPORT mode?  In other words, if you take your hands off the sticks in SPORT mode will the P4 hold its horizontal position at any altitude?  Is VPS available in SPORT mode IF you are moving at horizontal velocities low enough for VPS to function or is VPS completely deactivated in SPORT mode?

GPS works in Sport mode (which should be considered as a overboost P mode).

david.p.mann@ea Posted at 2016-3-10 01:42
I assume that GPS position hold is NOT available in ATTI mode on the P4, just like it was not avai ...

Yes, in ATTI mode it will drift in the wind, same as P3.

Ulysse Posted at 2016-3-10 01:52
GPS works in Sport mode (which should be considered as a overboost P mode).

Ken -

In SPORT Mode on the P4 do you have essentially the same capabilities as when flying in P-GPS mode on the P3 PLUS speed up to 20 m/s (44 mph)?  If this is NOT the case, what capabilities do you lose in SPORT mode on P4 that you have when flying P-GPS mode with P3?

If so, that is huge improvement and a GREAT feature that would potentially justify upgrading from P3 to P4 (in addition to all the other great P4 features - ActiveTracking, dual IMUs, dual compass, extended battery life, and, of course, collision avoidance system in forward flight mode).

I found the following statements in the FAQ on the Phantom 4 on the DJI website:


18. What’s the horizontal speed of Phantom 4 in ATTI Mode?
  The horizontal speed of the Phantom 4 in ATTI mode is 44.7mph (72kph).

19. What is the difference between Sport Mode and ATTI Mode?
  Though Phantom 4 can fly up to 44.7mph in both Sport Mode and ATTI Mode, Phantom 4 will use GPS/Glonass and its Vision Positioning System to achieve precision while hovering. In ATTI Mode, GPS and Vision Positioning System will not function to aid the aircraft in terms of hovering or navigation.

NOTE: although not clearly stated in the answer to 19 above, I infer that this means that in SPORT mode both GPS/Glonass and the VPS system are used to achieve precision while hovering, while the P4 can fly up to 44.7 mph. Wow!  In this case, I'm not sure why one would ever choose to use ATTI Mode; it doesn't offer any speed advantages over SPORT mode and SPORT mode still uses GPS/GLONASS and VPS during hover.  The answer above also suggests that VPS is not available in SPORT mode when the P4 is moving at any non-zero velocity.

Can one of the DJI forum reps please confirm this?

david.p.mann@ea Posted at 2016-3-10 11:44
I found the following statements in the FAQ on the Phantom 4 on the DJI website:

In Sport mode the P4 tilts up to 45°.
When tilted that much, the VPS is not pointing straight down and would give misleading results if used.
Also the forward facing object avoidance sensors would be looking down rather than facing forward.