Waypoint Mission (IMPOSSIBLE) !!!!! 🇦🇮🦘

[Squidinc]

Hi all,

This is a "heads up" to be cautious when flying a preplanned waypoint mission, as altitudes can change from what you originally set!

Page 41 of the Air 3 manual states - "THE FLIGHT ROUTE WILL CURVE BETWEEN WAYPOINTS, SO THE AIRCRAFT ALTITUDE BETWEEN WAYPOINTS MAY BECOME LOWER THAN THE ALTITUDES OF THE WAYPOINTS DURING THE FLIGHT. MAKE SURE TO AVOID ANY OBSTACLES BELOW WHEN SETTING A WAYPOINT"

Recently I almost lost my Air 3 into the ocean because of this. This was due to a negative altitude being implemented by the waypoint flight that was not known until actually flying the mission. @KenG has had a similar issue, with DJI confirming that a new core board module was needed for his Air 3 and are replacing it under warranty.

Here is a short fun video of what happened in my case utilising my AirData stats. You can see how I was climbing nicely until suddenly at waypoint F a negative altitude is applied. In a state of panic I hit RTH with a second to spare. Enjoy!

Waypoints Mission (Impossible)-4K.mov

@Droning on and on...

 

[MARK (LI)]

Looks like quick thinking saved you....good thing you were paying attention

 

[DoomMeister]

This sounds like DJI is using a Curved Cable Camera with their waypoint missions. Each waypoint will be passed through, but the flight path will be a curve through those points to achieve smooth cinematic flight and video.

Other manufacturers have used this same approach and flight planning must allow for this. Also remember to factor in flight speed. The faster the speed the more the curves will deviate between waypoints.

 

[DJ Wes]

This sounds like DJI is using a Curved Cable Camera with their waypoint missions. Each waypoint will be passed through, but the flight path will be a curve through those points to achieve smooth cinematic flight and video.

This is correct. DJI uses a Catmul-Rom spline to define the flight path from the waypoints.

Also remember to factor in flight speed. The faster the speed the more the curves will deviate between waypoints.

Speed has nothing to do with the path. Geometry alone defines the path.

 

[MS Coast]

This is correct. DJI uses a Catmul-Rom spline to define the flight path from the waypoints.


Speed has nothing to do with the path. Geometry alone defines the path.

And the curved flight path happens in all three dimensions, not just two.

I had assumed that altitude would be controlled to the set values. I created a simple waypoint flight that involved moving to two locations at 200' AGL and descending vertically to 50'. The flight path was a smooth curve downward between the waypoints, which could have been a serious problem if there were obstacles between the waypoints.

 

[Pinedar]

Thanks for sharing! Did the altitude change after the mission began? How did RTH initiate?

 

[DoomMeister]

This is correct. DJI uses a Catmul-Rom spline to define the flight path from the waypoints.
View attachment 174957

Speed has nothing to do with the path. Geometry alone defines the path.

Thanks for the information update. Good to know speed does not affect the curves.

 

[4006448]

Love the music! Perhaps Mission Impossible required a submersible shore landing? Glad it worked out well with your quick action. Trust an Aussie to find the device’s limits.

 

[Shuttersky597]

Hi all,

This is a "heads up" to be cautious when flying a preplanned waypoint mission, as altitudes can change from what you originally set!

Page 41 of the Air 3 manual states - "THE FLIGHT ROUTE WILL CURVE BETWEEN WAYPOINTS, SO THE AIRCRAFT ALTITUDE BETWEEN WAYPOINTS MAY BECOME LOWER THAN THE ALTITUDES OF THE WAYPOINTS DURING THE FLIGHT. MAKE SURE TO AVOID ANY OBSTACLES BELOW WHEN SETTING A WAYPOINT"

Recently I almost lost my Air 3 into the ocean because of this. This was due to a negative altitude being implemented by the waypoint flight that was not known until actually flying the mission. @KenG has had a similar issue, with DJI confirming that a new core board module was needed for his Air 3 and are replacing it under warranty.

Here is a short fun video of what happened in my case utilising my AirData stats. You can see how I was climbing nicely until suddenly at waypoint F a negative altitude is applied. In a state of panic I hit RTH with a second to spare. Enjoy!

Waypoints Mission (Impossible)-4K.mov

@Droning on and on...

I have actually experienced this with my Mavic 3 classic, Specta Air, and my new Air 3. Waypoints have suspended when the point was set at 15 ft and during run it descended to 6. Three different drones , same thing.

 

[Squidinc]

Thanks for sharing! Did the altitude change after the mission began? How did RTH initiate?

Not sure when exactly the waypoint flight altitude changed. The sticks do not respond when flying a waypoint flight, so in my panic I hit the RTH button as a last resort. It worked….. Whew!

 

[Shuttersky597]

DJI knew exactly what to do with the pause/ RTH button.

 

[Kiwicbrthou]

Well that’s about as close as you’d ever want to get!
Just goes to show you can’t afford to get too distracted by stuff going on around you.