Litchi Flight gone wrong! So close to crashing Mavic 2 Zoom

[Jetdriver100]

I set up a waypoint mission on Litchi. Flying the drone around our field and placing the waypoints manually as I went to be sure it was far from everything.
I then have flown the waypoint mission 3 times and every time went totally smooth. The purpose of the little flight is just to record the difference of the property from late winter, into spring and finally when leave's come out.
The other day I flew the same mission and the drone fly's into a tree branch! Luckily, it didn't even scratch a prop or anything. UNREAL!
The only thing I did differently on this flight was to take off from a different home point than I used for the first 3 flights.
The starting (home point) altitude was about 5 feet higher than my first flights. I'm wondering if that is what caused this to happen?

 

[sar104]

Impossible to answer without seeing the mission profile and flight log.

 

[Jetdriver100]

Impossible to answer without seeing the mission profile and flight log.

Mission Hub - Litchi

Litchi's Mission Hub lets you plan waypoint flights and later execute them using the mobile Litchi app.

flylitchi.com

I think I just figured it out! I didn't have the above ground check box checked on the waypoints! I thought I did.. So... Taking off from a different altitude would have caused it to be flying lower then the waypoints were set?

 

[Jetdriver100]

Does the Airdata site give you all the details? Or have to download from the drone itself?

 

[Drones.n.Pixels]

I set up a waypoint mission on Litchi. Flying the drone around our field and placing the waypoints manually as I went to be sure it was far from everything.
I then have flown the waypoint mission 3 times and every time went totally smooth. The purpose of the little flight is just to record the difference of the property from late winter, into spring and finally when leave's come out.
The other day I flew the same mission and the drone fly's into a tree branch! Luckily, it didn't even scratch a prop or anything. UNREAL!
The only thing I did differently on this flight was to take off from a different home point than I used for the first 3 flights.
The starting (home point) altitude was about 5 feet higher than my first flights. I'm wondering if that is what caused this to happen?

It all depends how you configured the points. If I'm not mistaken, Litchi has options to configure them in various ways, based on starting altitude or predefined altitude, so it is possible that this is exactly what happened.

 

[sar104]

Does the Airdata site give you all the details? Or have to download from the drone itself?

The profile that the aircraft flew matched the mission profile up to WP 3, then it failed to climb to the specified heights of the subsquent waypoints. The reason is not apparent from the log or profile, but it was not caused by the AGL setting or lack of it.

 

[Jetdriver100]

The profile that the aircraft flew matched the mission profile up to WP 3, then it failed to climb to the specified heights of the subsquent waypoints. The reason is not apparent from the log or profile, but it was not caused by the AGL setting or lack of it.

Mmm.. That is interesting! When the wind slows down a bit, I am going to try it again, but this time stand on the other side of that tree so I can hit the pause if I see it not doing what it should be doing.. I wonder why? As stated, the first 3 times were perfect!

 

[dd377]

I have flown Litchi literally hundreds of times. If your statement is correct and you didn't have the above ground box checked, that more than likely was your issue. Important to always
double check Settings before each flight and have above ground level checked for each waypoint.

 

[Camino Ken]

I am a little confused with all the altitude comments. I just acquired Litchi for IOS and am a Litchi newbie. On the waypoint settings I only see one altitude setting and I assume it is the altitude above the takeoff point. I don’t see any above ground or actually any of the other options mentioned above. I am I missing something?

 

[ratjr15]

I am a little confused with all the altitude comments. I just acquired Litchi for IOS and am a Litchi newbie. On the waypoint settings I only see one altitude setting and I assume it is the altitude above the takeoff point. I don’t see any above ground or actually any of the other options mentioned above. I am I missing something?

You'll only see the above ground option on the mission hub on the net.

 

[sar104]

I am a little confused with all the altitude comments. I just acquired Litchi for IOS and am a Litchi newbie. On the waypoint settings I only see one altitude setting and I assume it is the altitude above the takeoff point. I don’t see any above ground or actually any of the other options mentioned above. I am I missing something?

You can choose to fly a mission where you set altitudes AGL rather than altitude relative to the takeoff point, but note that there is a catch - Litchi assumes that the ground elevation at the takeoff point is the same as the ground level at waypoint 1. If you take off from a location either higher or lower than the ground elevation under WP1 then all the waypoint heights will be offset by the difference. That's inevitable, of course, because the aircraft has no knowledge of altitude AMSL. I always leave WP1 as a spare waypoint to put at the takeoff point, avoiding any confusion.

 

[Camino Ken]

You can choose to fly a mission where you set altitudes AGL rather than altitude relative to the takeoff point, but note that there is a catch - Litchi assumes that the ground elevation at the takeoff point is the same as the ground level at waypoint 1. If you take off from a location either higher or lower than the ground elevation under WP1 then all the waypoint heights will be offset by the difference. That's inevitable, of course, because the aircraft has no knowledge of altitude AMSL. I always leave WP1 as a spare waypoint to put at the takeoff point, avoiding any confusion.

Thanks, good to know, especially in my case where I have significant elevation changes over fairly short distances.

 

[Jetdriver100]

My guess is that had to be the problem as I flew the same mission 3 times without a hitch. The one time it messed up is from a different elevation. My guess is about 6 feet higher from behind my garage instead from down in the field where I had waypoint 1 set right above me. Also, I did not have the above ground check box checked.. As..... I thought once you checked it once, it would default to that. NOT THE CASE! Always check that you have that checked if that's what you want .

Still haven't had a chance to try the mission again. I have the box checked now above ground and I will try it from both out in the field and from behind the garage at a different elevation and will watch it very closely to see if there is a difference in the way it fly's around that tree!! DAM TREE! yes.. That DAMM TREE! It will be interesting now though After trying the flight twice from 2 different start points to see what it does! I will keep you posted!

Hopefully tomorrow I can get a flight in. As the same old weather seems to keep putting me...........

 

[Jetdriver100]

You can choose to fly a mission where you set altitudes AGL rather than altitude relative to the takeoff point, but note that there is a catch - Litchi assumes that the ground elevation at the takeoff point is the same as the ground level at waypoint 1. If you take off from a location either higher or lower than the ground elevation under WP1 then all the waypoint heights will be offset by the difference. That's inevitable, of course, because the aircraft has no knowledge of altitude AMSL. I always leave WP1 as a spare waypoint to put at the takeoff point, avoiding any confusion.

Yes.. I think it is a wise idea to set waypoint 1, as your starting point (home point) to avoid errors. And alway start from that point... or, an elevation equivalent to your starting point (waypoint 1) (home point).

 

[sar104]

Yes.. I think it is a wise idea to set waypoint 1, as your starting point (home point) to avoid errors. And alway start from that point... or, an elevation equivalent to your starting point (waypoint 1) (home point).

I just move WP1 to the takeoff location once in the field.

 

[Jetdriver100]

I just move WP1 to the takeoff location once in the field.

That's a great idea!