mavic did not rth

[sar104]

@Keule illustrated the problem exactly. The attempt to return is clearly apparent in the aircraft telemetry, and shows the performance limitations in RTH mode:



After RTH was engaged the aircraft aligned its heading to the home point (100°) and applied the maximum pitch (in RTH mode) of -25°. Roll remained at zero, indicating that there was no cross wind on that course - it was pure headwind on that course - as shown on the AirData wind computation. The aircraft was still being blown backwards at nearly 1 mph - implying a wind speed in excess of 30 mph.

At this point the only viable option was to switch to sport mode, since that increases the available pitch to 35° and would have permitted slow progress back to the east under manual control. However, even in sport mode there was insufficient battery reserve to have returned over 3 km into that wind.

Did you locate the aircraft?

 

[BJR981S]

This was the fifth or sixth flight with brand new mavic. I have a p4 and another mavic and both
will initiate rth after 3 secs. disconnected. Clearly you can see after numerous disconnects and
many many over 3 secs. the mavic actually was getting further away. I know the height was
extreme but b4 disconnect and when i was losing signal i increased altitude trying in vain
to restablish connection. So please dont relentlessly tell me how wrong and all the rules
broken cause i am well aware.I hope this is right file. does anyone know what happened?
in my settings everything was and still is set to rth if disconnect or low battery.
You will see that the flight record SAYS its coming home but never does even when critical
battery level is reached. Also why does the file not complete itself.
The GREAT news is it threaded a 8 foot wide gap between two buildings with trees and
houses and businesses everywhere. I will try to figure a way to load the video.
the video does not appear on my ipad pro 9.7 but does appear on sd card when played
back on computer.
Anyway is this the right file?
i opened it in excel but do not know how to load that here.
Any suggestions

You answered your own question when you say it threaded it’s way between buildings. You don’t get close to Buildings it will screw up your compass heading. That is a big no no. Do not fly in significant built up areas. You get interference as you did then a RTH flyaway as the compass is pointing in the wrong direction. And don’t think you will get a compass warning. You won’t.

 

[sar104]

You answered your own question when you say it threaded it’s way between buildings. You don’t get close to Buildings it will screw up your compass heading. That is a big no no. Do not fly in significant built up areas. You get interference as you did then a RTH flyaway as the compass is pointing in the wrong direction. And don’t think you will get a compass warning. You won’t.

There was no compass problem on this flight - just strong winds.

 

[Paul2660]

Another Arkansasan here. Last 2 weeks the winds have been crazy here.

I was just curious, did you get any wind warnings from the app? I have flown both the P4 and Mavic and both are effected by the wind considerably. The other day, I was in the Ozarks, clear and calm at base, but by 200 feet up heavy winds, blowing from the west. UAV forecast told me around 15 to 20 MPH gusting. I did not attempt a long flight, but have noticed that the wind warnings on the Mavic seem to add up, in that after you get 3 or 4 in a row the video feedback will start to get errors, eventually locking up or the app fails to respond. The other day, I had 3 or 4 in a row the last being "high Velocity winds land immediately". When this one comes up, I just pull the aircraft down in altitude a bit, to see if things will stabilize which most times they do. I have wondered if enough wind warnings are recorded by the app if the app will start to attempt to land the Mavic even with plenty of battery left.

It's hard to fly in Arkansas without a wind warning, at least winter and spring, but having seen other threads like this where the Mavic could not fly back due to the headwinds, I have tried to pay close attention to the wind at launch. Best case scenario is fly away into the wind, possibly in sport mode to get where you want to be, knowing that on return you will be with the wind. So far the winds have be prevailing from the west this Spring. You have to watch that the motors stay in an OK temperature range during the flight out in sport mode.

Back in the winter, we were running rice fields and the wind was very strong again out of the west. I was amazed to see that a Mavic in Sport mode could get out 2700 feet into such a wind, and then fly back with the wind for 2 separate flights and still have 20 percent of battery left.

Hope you find the drone as it odds are landed under control, but on or in what is the questions.

Paul Caldwell
LR Ark

 

[sar104]

Another Arkansasan here. Last 2 weeks the winds have been crazy here.

I was just curious, did you get any wind warnings from the app? I have flown both the P4 and Mavic and both are effected by the wind considerably. The other day, I was in the Ozarks, clear and calm at base, but by 200 feet up heavy winds, blowing from the west. UAV forecast told me around 15 to 20 MPH gusting. I did not attempt a long flight, but have noticed that the wind warnings on the Mavic seem to add up, in that after you get 3 or 4 in a row the video feedback will start to get errors, eventually locking up or the app fails to respond. The other day, I had 3 or 4 in a row the last being "high Velocity winds land immediately". When this one comes up, I just pull the aircraft down in altitude a bit, to see if things will stabilize which most times they do. I have wondered if enough wind warnings are recorded by the app if the app will start to attempt to land the Mavic even with plenty of battery left.

It's hard to fly in Arkansas without a wind warning, at least winter and spring, but having seen other threads like this where the Mavic could not fly back due to the headwinds, I have tried to pay close attention to the wind at launch. Best case scenario is fly away into the wind, possibly in sport mode to get where you want to be, knowing that on return you will be with the wind. So far the winds have be prevailing from the west this Spring. You have to watch that the motors stay in an OK temperature range during the flight out in sport mode.

Back in the winter, we were running rice fields and the wind was very strong again out of the west. I was amazed to see that a Mavic in Sport mode could get out 2700 feet into such a wind, and then fly back with the wind for 2 separate flights and still have 20 percent of battery left.

Hope you find the drone as it odds are landed under control, but on or in what is the questions.

Paul Caldwell
LR Ark

There were 10 high wind warnings during that flight, starting at 138 s at an altitude of 209 ft. There were 4 more warnings as the OP continued to climb the aircraft to over 1000 ft AGL.

 

[Aerial West]

the winds werent enuf to keep the mavic from rth or at the very least show signs it was trying.
It failed to rth

remember winds on ground are never what they are at altitude. even 30 feet up they can be very different.

 

[JohnnyD913]

@Keule illustrated the problem exactly. The attempt to return is clearly apparent in the aircraft telemetry, and shows the performance limitations in RTH mode:

View attachment 36529

After RTH was engaged the aircraft aligned its heading to the home point (100°) and applied the maximum pitch (in RTH mode) of -25°. Roll remained at zero, indicating that there was no cross wind on that course - it was pure headwind on that course - as shown on the AirData wind computation. The aircraft was still being blown backwards at nearly 1 mph - implying a wind speed in excess of 30 mph.

At this point the only viable option was to switch to sport mode, since that increases the available pitch to 35° and would have permitted slow progress back to the east under manual control. However, even in sport mode there was insufficient battery reserve to have returned over 3 km into that wind.

Did you locate the aircraft?

sar104 awesome job sir.
Many thanks for putting the data into layman terms.
Yes I recovered the Mavic completely unharmed.
It threaded the needle between two buildings into
A 7-8 foot wide only path.
Not bad for auto landing
Thanks again
JohnnyD913

 

[JohnnyD913]

Another Arkansasan here. Last 2 weeks the winds have been crazy here.

I was just curious, did you get any wind warnings from the app? I have flown both the P4 and Mavic and both are effected by the wind considerably. The other day, I was in the Ozarks, clear and calm at base, but by 200 feet up heavy winds, blowing from the west. UAV forecast told me around 15 to 20 MPH gusting. I did not attempt a long flight, but have noticed that the wind warnings on the Mavic seem to add up, in that after you get 3 or 4 in a row the video feedback will start to get errors, eventually locking up or the app fails to respond. The other day, I had 3 or 4 in a row the last being "high Velocity winds land immediately". When this one comes up, I just pull the aircraft down in altitude a bit, to see if things will stabilize which most times they do. I have wondered if enough wind warnings are recorded by the app if the app will start to attempt to land the Mavic even with plenty of battery left.

It's hard to fly in Arkansas without a wind warning, at least winter and spring, but having seen other threads like this where the Mavic could not fly back due to the headwinds, I have tried to pay close attention to the wind at launch. Best case scenario is fly away into the wind, possibly in sport mode to get where you want to be, knowing that on return you will be with the wind. So far the winds have be prevailing from the west this Spring. You have to watch that the motors stay in an OK temperature range during the flight out in sport mode.

Back in the winter, we were running rice fields and the wind was very strong again out of the west. I was amazed to see that a Mavic in Sport mode could get out 2700 feet into such a wind, and then fly back with the wind for 2 separate flights and still have 20 percent of battery left.

Hope you find the drone as it odds are landed under control, but on or in what is the questions.

Paul Caldwell
LR Ark

Paul,
Thank you for your response, nice to have another
Arkansan to talk with.
It sounds like you pay very serious attention to
Conditions before flight.
You can be certain that I have learned my lesson.
The great news is the Mavic made a miracle landing
Between two buildings and they were off the main
Roads.
Very lucky I am indeed.
I haven’t ever had the app tell me to land though.
I also have a p4 and many times I have had multiple
Wind warnings but ignored them.
Yes it is a difficult thing to fly here with the wind.
I panicked I quess that flight and never even thought to get into sport mode.
I know now but hope I never need to make that decision because I wasn’t paying attention,
I have learned my lesson.
John Schnebly

 

[Miki121]

There was strong wind. The aircraft wasn't able to fight the wind back home.

View attachment 36524 View attachment 36525 View attachment 36526

Hey, this is amazing, how did you manage to get these data ?

 

[Keule]

how did you manage to get these data ?

I put the .txt log into a paid Airdata.com account.
Then you have those data being displayed ;-)

 

[Miki121]

I put the .txt log into a paid Airdata.com account.
Then you have those data being displayed ;-)

this is way to cool =) thanks !

 

[Mossiback]

...Yes I recovered the Mavic completely unharmed. It threaded the needle between two buildings into A 7-8 foot wide only path...

You are truly a lucky man.

Yet another thing about RTH, if you are ascending up the side of a hill staying closer to the ground in calmer air, you will eventually be much higher than your RTH height setting because it is relative to your home point not actual AGL. If you loose signal and RTH is initiated, it will not descend but will try to fly back at its current height. This could send it into stronger winds that it may not be able to fight.