Please select Into the mobile phone version | Continue to access the computer ver.
Altitude settings when launching a mavic air from a cliff top
2331 13 2018-3-14
Uploading and Loding Picture ...(0/1)
o(^-^)o
fans1b839f0c
lvl.3
New Zealand
Offline

Situation: I set my max altitude to 200ft and launch from the top of a 300ft Clif and fly out over the sea then descend to 50ft and take some photos. Question: If I push the ‘Home’ button, will the mavic air fly to the ‘Return Home’ altitude of 200ft then fly towards home and crash ito the cliff?

Or: Will it calculate that it has to fly 500ft (200 ft set on max altitude plus 300ft cliff hight) before heading home?
It seems obvious to set the max height to 500ft before take off but as the aircraft flys to this pre determined altitude when the ‘Home’ button is pushed could the aircraft go to 800ft ? (500ft plus cliff night of 300ft)
I have searched everywhere for the answer to this question so any help would be appreciated.
Cheers in advance.
2018-3-14
Use props
M2Wair
Captain
Flight distance : 1171719 ft
  • >>>
Ireland
Offline

It will calculate height from launch point and RTH at the height you set above launch point.  So it would return to top of cliff.
2018-3-14
Use props
CoreyB10
Captain
Flight distance : 204803 ft
  • >>>
United Kingdom
Offline

M2Wair Posted at 2018-3-14 02:07
It will calculate height from launch point and RTH at the height you set above launch point.  So it would return to top of cliff.

This would be good to see if it actually works while standing below the cliff with a massive catch net.......
2018-3-14
Use props
M2Wair
Captain
Flight distance : 1171719 ft
  • >>>
Ireland
Offline

CoreyB10 Posted at 2018-3-14 02:54
This would be good to see if it actually works while standing below the cliff with a massive catch net.......

So what you are saying is it would smash into the cliff and not return to it's home point.......  Eeeerrrmmm WRONG

2018-3-14
Use props
M2Wair
Captain
Flight distance : 1171719 ft
  • >>>
Ireland
Offline

After setting your home point 'on top of the cliff', it is from there your RTH height is set, not below. flying lower than your recorded home point will show as a minus negative altitude, hit RTH and the aircraft will climb to the set height above the cliff face at 200ft and not a minus altitude.
OP ensure you hear those comforting words "Your homepoint has been recorded, please check it on the map" and you are good to go.


2018-3-14
Use props
QuadKid
Captain
Flight distance : 482349 ft
United States
Offline

M2Wair Posted at 2018-3-14 03:05
So what you are saying is it would smash into the cliff and not return to it's home point.......

No it should work as in Post #2, the RTH is always calculated from the Home Point Altitude, now if you were to loose GPS signal because the cliff is blocking the signal(s), (depends on where the satellites are on the horizon) the drone would not be able to RTH until the signal is regained. When you decend from the cliff your altitude will show a - number.
2018-3-14
Use props
A CW
Captain
Flight distance : 12840059 ft
  • >>>
United Kingdom
Offline

Note your max flight altitude setting is not your RTH altitude setting - that is set differently but is indeed calculated above the home point and not its position at the point of signal loss.
2018-3-14
Use props
CoreyB10
Captain
Flight distance : 204803 ft
  • >>>
United Kingdom
Offline

M2Wair Posted at 2018-3-14 03:05
So what you are saying is it would smash into the cliff and not return to it's home point.......  Eeeerrrmmm WRONG

Looking at the forum post's and past issues with all craft every now and then, nothing would surprise me. There is no mention of it will crash at all, just use caution and make sure all settings are done correctly before the flight. There are more and more on the forum who use it as an unofficial instruction book.
2018-3-14
Use props
M2Wair
Captain
Flight distance : 1171719 ft
  • >>>
Ireland
Offline

CoreyB10 Posted at 2018-3-14 05:15
Looking at the forum post's and past issues with all craft every now and then, nothing would surprise me. There is no mention of it will crash at all, just use caution and make sure all settings are done correctly before the flight. There are more and more on the forum who use it as an unofficial instruction book.

100% agree, all users should exercise a little caution whenever you take to the skies, a little due diligence and reading the instruction manual and setting the AC up correctly are fundamental requirements for safe flights, why it is often neglected baffles me backwards .   
2018-3-14
Use props
Dorset_Horn
First Officer
Flight distance : 93379 ft
United Kingdom
Offline

Just a thought - it is probably worth checking the wind direction. If it's onshore, you should be OK. If it's offshore, I wouldn't be confident your Mavic could fight it's way homeward, before it lands due to low battery, in the briny...
2018-3-14
Use props
fans1b839f0c
lvl.3
New Zealand
Offline

Thanks for your answers guys, I realise it’s a hypothetical situation we are discussing here but never the less an interesting detail to understand. I realise that correct settings before take off is imperative and go as far to say that almost everyone would set the RTH altitude lower than max altitude.

I take from your answers then that in certain situations like flying on cliff tops,  if for some reason the RTH altitude has been set above the max altitude the aircraft will over ride the max altitude when returning home after  the RTH button ihas been pushed?

Cheers.
2018-3-14
Use props
Omar M.
New
Italy
Offline

Hi guys,

I have a similiar doubt, if i set max altitude to 200feet and i fly over a cliff with a drop over 600feet , what happen to drone? It's go down automatically to 200ft?
2018-9-19
Use props
Ridg
First Officer
Flight distance : 232306 ft
United Kingdom
Offline

Omar M. Posted at 2018-9-19 07:40
Hi guys,

I have a similiar doubt, if i set max altitude to 200feet and i fly over a cliff with a drop over 600feet , what happen to drone? It's go down automatically to 200ft?

no, as soon as you're more than 10m above the ground the DJI consumer drones have no concept of AGL.

Altitude is calculated from the point of take off so if you fly of a cliff you maintain the same height as above the cliff.
2018-9-19
Use props
G_Sig
Captain
Flight distance : 5975574 ft
Iceland
Offline

Omar M. Posted at 2018-9-19 07:40
Hi guys,

I have a similiar doubt, if i set max altitude to 200feet and i fly over a cliff with a drop over 600feet , what happen to drone? It's go down automatically to 200ft?

To bee on the safe site I would not set max altitude bu just set RTH altitude.
If you set max it might stop when it is in -200 but have not tested it .
I have used both Phantom 3S and Mavic Pro to -200 m or around -600 ft without any error.
2018-9-19
Use props
Advanced
You need to log in before you can reply Login | Register now

Credit Rules