Out with the Spark last night and was up at 100m getting a shot of the cut grass in the fields. Suddenly got a battery fault warning on screen with just over 7 mins claimed flying time left.
I brought it down using the left stick full down but was worried at its very slow rate of descent.
Once down i changed the battery and did a couple of tests. Tried it again with the controller in normal and also in sport mode. Sport mode is slighjtly quicker but still a lot slower than i would like if i wanted to get it down urgently.
Is this something i will ust have to live with or is there a better way to reduce altitude quickly? (and safely)

Best best is to fly forward and down in Sport mode for the quickest descent

Duncdude,

With 7 minutes left you had plenty of time.

Spark lands with the following speeds:
- Sport mode with full throttle down - 2 metres / sec
- P-GPS, OPTI, ATTI mode with full throttle donw - 1.5 metres / sec
- Autolanding (RTH or battery depleted) - 1.2 metres / sec

In summary, you can get it down from 100 metres altitude in about 50 seconds if you use Sport mode.

You have to live with it.  It is a limit of quadcopter with fixed pitch propellers.  

The Spark can only slowly decend because it relies on motor speed for lift.  Slowing down the motors lets it come down but it becomes unstable if the motors are slowed down too much.  Trying to decend faster by slowing the props down more would cause the drone to tumble out of control.

Model helicopters have variable pitch rotors that can deflect up +18 degrees for more pitch and hard thrust up.  They can also deflect their rotor blades down -18 degrees for down thrust.  They can decend very fast while the rotor speed stays the same (stay stable and not tumble) but thrust is now down.  Fun.

Hi!

I have experimented a bit with Sport+ mode (google is your friend ). Descend with 8 m/s was a bit scary as it tumbled a bit, but from what I have seen no VRS. Now I am flying with 8m/s ascend and 6m/s descend rate - works perfect!

Greetz
Weesel

Mirek6 Posted at 2018-6-29 05:33
Duncdude,

With 7 minutes left you had plenty of time.

Mirek6 - is your info from DJI or is it your measurement? I ask because the manual says 3m/sec and does not specify mode. Thanks.

Marlow,

These are my measurements based on my logs during my flights.

Because I help other forum members with analysis of their flight situations I keep detailed notes.

Manual is generic - does not go into a lot of details which we experience every day.

Mirek