I've had some Phantom experience and the Inspire 1 is my first drone. Overall I've been incredibly impressed with it's performance especially in gps mode in the wind. Pretty unbelievable how well the craft stays in one place.

One small thing I've noticed is that when I full throttle forward I notice a drop in altitude. Is this normal or am I doing something wrong?

Thanks!

It's normal..... compare it to the spoiler on a car.. It's angling itself in a direction to move forward which also forces it closer to the ground  (downward air pressure - wind tunnel style)... Try the same move at half speed and you'll see the flight controller can compensate...

too long: didn't read - the inspire is really fast
-chris

Thank's Chris for the input. It makes sense but I don't see any reason why the firmware couldn't be updated to compensate for this. When I throttle forward, that should be the only direction the craft moves in. Anyone else care to chime in with their thoughts on this? Seems like it could be an easy fix for dji in a firmware update to just add a little lift when the inspire is at full throttle or am I missing something else?

david.vollrath. Posted at 2015-2-22 22:17
Thank's Chris for the input. It makes sense but I don't see any reason why the firmware couldn't be  ...

David
There are too many variables to take into account for them to compensate for sink within the software.
The rotor disk doesn't supply lift in exactly the same way a fixed wing does.
For instance, whilst the rotor disk is level both blades are giving full lift.
But when they are moving along into oncoming air only the advancing blade is giving full lift.
The retreating blade is giving less and the faster the craft moves along the worse it gets.
In essence when you pitch the craft forwards you are doing the same as pointing a fixed wing down.
So there will be sink and if done abruptly noticeably so.
Also whilst on the subject, from what I have read.
It looks as though quite a few are under the impression that the lift generated by the rotor is from the air expelled by the rotor downwards.
In fact this only supplies a marginal amount and only when in full ground effect.
The air pushed through is disturbed, dirty air and not very good at giving lift.
That is when dropping into this disturbed descending air, Vortex Ring effect can come knocking.
Hope that helps.

Helicopter Aerodynamics 101!
It is normal to lose altitude when you input forward (cyclic/Right stick in Mode2) stick movement.
Lift, Weight, Thrust and Drag.
Lift opposes Weight and Thrust opposes Drag.
In a hover Lift and Thrust are opposing Weight and Drag. Picture your I1 from a profile view, Lift and Thrust are two arrows pointing straight up and Weight and Drag are two arrows pointing straight down.
In a stable constant altitude hover Lift and Thrust must equal Weight and Drag to maintain a constant altitude.
When you move the (cyclic) stick forward (right stick Mode2) to initiate forward flight you are taking some of your Lift energy and tilting it forward. You are taking some of your power needed to hover at a constant altitude and turning it into Thrust (forward flight in this case). To maintain a constant altitude (not sink) you need to add power back to Lift (push up on the left stick Mode2). Slow is better for control inputs, the rotors will become more efficient as speed builds so you can reduce power as forward flight is established (Translational lift).
Easier to visualize with pictures I am sure you can google it and find some illustrations.
I would not worry too much about Dissymmetry of Lift on multi rotors. I would not concern myself too much with Settling with Power (Vortex Ring State) on RC aircraft, it is harder to get into than out of.
Hope this was useful and not too confusing.

Dude this is a performance multi-rotor heli. It's a different animal than the Phantom. This guys were nice enough to break down the basics, but you have to get out there and fly to learn all of the nuancing of your bird.  The Inspire has only so much available power. Just imagine, If you're flying level at 20 m/s and all of the sudden while still giving it full pitch down cyclic you go full throttle...do you think the Inspire will still be going 20 m/s forward while ascending 5 m/s.