I was out flying my Mavic Air in the city (not the best idea) when it suddenly starts acting out of control.  One moment im flying it forward before it violently flies sideways by itself into the face of a building and subsequently crashes (seemingly on its own).

Has anyone experienced anything similar? How can this be possible?

more info: I was flying in ATTI mode. The file and flight recorded video . At, 28-29second, the drone drift forward from the momentum, before going haywire.

logs: http://www.phantomhelp.com/LogViewer/3N8B0GGWYZ10Z60NKVPF/

video: https://streamable.com/hb3c6

Unfortunately. Just looks like pilot error from initial impressions of the log.  

Took off before GPS has a solid lock and something that disabled your obstical avoidanance which usually if it disables itself from lack of it being able to see obstical or being at a steep angle.

As for los if control, that just attitude mode normal flight pattern.. if I was on my PC I could maybe download ur log and look at it way closer.. but this on first impressions looks like a rookie mistake.

Atti mode is basically altitude hold, it will drift about and it can be extremely responsive and feel more like a racer quad than like a professional stabilized camera drone because atti cannot lock position..

Was was flying in Atii mode on purpose?

I am sorry to know that your DJI Mavic Air crashed. Since the Drone crashed please send the Drone in for repair so that our DJI repair team will be able to know what really happened to your DJI Mavic Air. I will be posting the online repair request link ( https://repair.dji.com/repair/index ) so that you will be able to start processing the repair. Please sync the flight records using the DJI Go 4 application as well.

They should print on the box in big, bold letters: DO NOT TAKE OFF IN ATTI MODE! RESULTS WILL BE UNPREDICTABLE!". And many will still do it.

Unfortunately, I didn't make sure to check that it hadn't locked into GPS mode yet. Although it crashed, luckily everything pretty much looks intact besides some nicks and scratches. However, when i tried to take off again , it didn't seem to generate enough lift to get off the ground.

Any ideas what could be wrong?

Very sorry to hear about your crash but am sure it will not be covered under warranty due to no home point/no gps flying in atti mode.  

Atti mode is the worst.  They should have some sort of warning that let's you know you're about to do it... Yes, yet ANOTHER warning.  

Can you post some pic's

djiuser_zlqvXPJauTwU Posted at 2018-6-29 12:09
logs: http://www.phantomhelp.com/LogViewer/3N8B0GGWYZ10Z60NKVPF/

That’s tough, sorry to here that, but it does tell you in your manual, to try landing immediately when going in to Atti mode.
I think going by what you say , you understand what happened.

oh no not another one

Sorry to read of your crash - be sure to know the basics of flight safety before you take off with the next one (no congested areas and wait for a GPS lock as in a home point on your map before you even arm the motors).

El Kab0ng Posted at 2018-6-29 13:40
Atti mode is the worst.  They should have some sort of warning that let's you know you're about to do it... Yes, yet ANOTHER warning.

"ATTI MODE" in the app (and on the mavic pro, the RC) is a bit of a giveaway.

This is just a simply lack of pre takeoff checks from the poster.

Before takeoff always check things like a good 10+ satellite lock, the compass direction on the map and home point location agrees with the real world and so on.  
If you dont, things are much more likely to crash.

The drone is in fact all still intact aside from one broken propeller and a couple straches. I have replaced the broken propellers but when i try to take off, all propellers seen to spin fine but it does not leave the ground. Any suggestions?

djiuser_zlqvXPJauTwU Posted at 2018-6-30 09:03
The drone is in fact all still intact aside from one broken propeller and a couple straches. I have replaced the broken propellers but when i try to take off, all propellers seen to spin fine but it does not leave the ground. Any suggestions?

Sounds like it's broken. Send it in for repair.

HereForTheBeer Posted at 2018-6-29 12:17
Unfortunately. Just looks like pilot error from initial impressions of the log.  

Took off before GPS has a solid lock and something that disabled your obstical avoidanance which usually if it disables itself from lack of it being able to see obstical or being at a steep angle.

Vision positioning wasn’t active because he was flying it at night, which.....read the instructions, dude. You should NOT be learning how to fly that drone in a public area at night.

Agentbolt Posted at 2018-6-30 11:43
Vision positioning wasn’t active because he was flying it at night, which.....read the instructions, dude. You should NOT be learning how to fly that drone in a public area at night.

i agree, no one should be flying at night while learning.   

i haven't been able to pull the log up on my PC to confirm what time the user was flying i just assumed was at night or it being mavic air, angle was too steep for OA to work. i just looked at the messages and basic into the log has from the link from my iPhone....  

Hi,

This charts says enough....
Flying at night with a not stabilized drone is really difficult, guess we all agree on that.

cheers
JJB

ghostrdr Posted at 2018-6-29 13:18
They should print on the box in big, bold letters: DO NOT TAKE OFF IN ATTI MODE! RESULTS WILL BE UNPREDICTABLE!". And many will still do it.

Can confirm, atti mode anything cannot be trusted. Daemons will take control of your drone and try to kill ya, I swears!

HereForTheBeer Posted at 2018-6-30 19:53
i agree, no one should be flying at night while learning.   

i haven't been able to pull the log up on my PC to confirm what time the user was flying i just assumed was at night or it being mavic air, angle was too steep for OA to work. i just looked at the messages and basic into the log has from the link from my iPhone....

Yep, almost wrecked my spark by flying at night AND in sports mode. Luckly it was just a gutter and I jumped the drone 20 feet to avoid it. That being said, I have not really flown that much at night because I get the weirdest wifi interfrence when normally I have no issues. Just begging for trouble in my opinion, and might not be legal to boot!

HereForTheBeer Posted at 2018-6-30 19:53
i agree, no one should be flying at night while learning.   

i haven't been able to pull the log up on my PC to confirm what time the user was flying i just assumed was at night or it being mavic air, angle was too steep for OA to work. i just looked at the messages and basic into the log has from the link from my iPhone....

Correct, started in opti mode, then Atti mode OA won’t work in Atti mode, rookie mistakes, but hopefully something was learned by this.

AlphaFlightNW Posted at 2018-7-1 00:34
Yep, almost wrecked my spark by flying at night AND in sports mode. Luckly it was just a gutter and I jumped the drone 20 feet to avoid it. That being said, I have not really flown that much at night because I get the weirdest wifi interfrence when normally I have no issues. Just begging for trouble in my opinion, and might not be legal to boot!

yea i see that too!  i wish i knew more about RF.. RF fascinates me.. at night wifi is very weird.  i dont know if its specifically the frequencies used or something to do with wifi standard that make nighttime environment/atmosphere reflect signals more/less.

there is a water tower in town, they have cellular systems on the tower, my mavic pro i can fly on the north/north east side of it without any signal issues, but i cannot for the life of me fly by the south/south west side without massive signal issues, being as im a curious person, i did this test and night and i cannot get within 500-1000 feet of that tower at all at night, even trying above it, during the day, being above the tower i get 5/5 signal, night comes i cannot within the 400 AGL limit near that tower at all.  

one of my future tests imma do is signal test but i need a good area to make runs back to back in day and then in the night...

gnirtS Posted at 2018-6-29 16:34
"ATTI MODE" in the app (and on the mavic pro, the RC) is a bit of a giveaway.

This is just a simply lack of pre takeoff checks from the poster.

I never leave the ground until I have GPS mode locked on.  I have flown drones that used the DJI Naza brain and accidentally flipping the remote to Atti mode during a flight usually meant the flight was going to end in a crash.  

HereForTheBeer Posted at 2018-7-1 19:26
yea i see that too!  i wish i knew more about RF.. RF fascinates me.. at night wifi is very weird.  i dont know if its specifically the frequencies used or something to do with wifi standard that make nighttime environment/atmosphere reflect signals more/less.

there is a water tower in town, they have cellular systems on the tower, my mavic pro i can fly on the north/north east side of it without any signal issues, but i cannot for the life of me fly by the south/south west side without massive signal issues, being as im a curious person, i did this test and night and i cannot get within 500-1000 feet of that tower at all at night, even trying above it, during the day, being above the tower i get 5/5 signal, night comes i cannot within the 400 AGL limit near that tower at all.  

Yeah... Let me see if I can remember some RF theory.

What I think might be happening  is like when your near a lake at night, you can hear sounds better from the other side than during the day. It might be that but Im not sure. Ill check my notes somewhere.
EDIT: Found an article that explains the phenomena a little better than i did: RF at night. that being said, this is mainly about reflection via the ionosphere with things like HAM or other communication radios. Perhaps its because the sunlight carrys some sort of dampener during the day for other wifi signals? TBH, I am not to sure myself. Hopefully some people with more experience with RF theory can come along and share their thoughts on this.

AlphaFlightNW Posted at 2018-7-3 19:30
Yeah... Let me see if I can remember some RF theory.

What I think might be happening  is like when your near a lake at night, you can hear sounds better from the other side than during the day. It might be that but Im not sure. Ill check my notes somewhere.

FCC on AM signals:
Because of the way in which the relatively long wavelengths (see Footnote 1) of AM radio signals interact with the ionized layers of the ionosphere miles above the earth's surface, the propagation of AM radio waves changes drastically from daytime to nighttime.  This change in AM radio propagation occurs at sunset due to radical shifts in the ionospheric layers, which persist throughout the night.  During daytime hours when ionospheric reflection does not occur to any great degree, AM signals travel principally by conduction over the surface of the earth.  This is known as "groundwave" propagation.  Useful daytime AM service is generally limited to a radius of no more than about 100 miles (162 km), even for the most powerful stations.

However, during nighttime hours the AM signals can travel over hundreds of miles by reflection from the ionosphere, a phenomenon called "skywave" propagation.  (Shortwave stations, which operate using AM modulation on several bands between between 2.3 MHz and 26.1 MHz, also use this phenomenon to broadcast still greater distances, up to thousands of miles.)  Because of this change in signal propagation from daytime to nighttime, if every AM station kept its daytime operating power at night, massive interference would result.

Why AM signals:
Not all radio waves travel farther at night than during the day, but  some, short and medium wave, which AM radio signals fall under,  definitely can given the right conditions. The main reason this is the  case has to do with the signal interacting with a particular layer of  the atmosphere known as the ionosphere, and how this interaction changes  from the nighttime to the daytime.

AlphaFlightNW Posted at 2018-7-3 19:30
Yeah... Let me see if I can remember some RF theory.

What I think might be happening  is like when your near a lake at night, you can hear sounds better from the other side than during the day. It might be that but Im not sure. Ill check my notes somewhere.

i have a friend that is into HAM and RF theory so much more.. i asked him about Wifi and he said Wifi is by far the worst wireless coms to use for outdoor use because of its hugely inconsistent properties.

Wifi 2.4 and 5.8ghz are not long wavelengths.  They are short.  Not radar short at 24.0ghz but pretty short.  They are very directional and don't skip or go around things.  I think you are getting run down by local wifi use increasing when home owners get home and start binge watching Doctor Who.  Home's with cell phones increasing usage and opening up more channels when people are home from work?

Hi Guys, another rookie here,just got a MA but still in box, so a biff question that will help me and hopefully other's, I fully understand the not taking off until the req no of Sat's are found,but imagine that in all the excitment of early flights many forget, so my question is if you forget and end up flying in ATTI mode then realise what's happening ,what's the best way to deal with the situation?

HEATYBOB Posted at 2018-7-3 23:38
Hi Guys, another rookie here,just got a MA but still in box, so a biff question that will help me and hopefully other's, I fully understand the not taking off until the req no of Sat's are found,but imagine that in all the excitment of early flights many forget, so my question is if you forget and end up flying in ATTI mode then realise what's happening ,what's the best way to deal with the situation?

HI,

Practise, practise and dont panic! Beacuse you cannot switch to ATTI on SPARK and MA no way to practise.
So IMO its best to buy a small cheap drone and learn to fly in "ATTI" mode.

Understand that flying in ATTI mode you have to stop the directed motion by yourself by opposite  steering. ( Left roll > drone goes left > RC stick mid position > drone still goes left.... ).

cheers
JJB

Gunship9 Posted at 2018-7-3 22:16
Wifi 2.4 and 5.8ghz are not long wavelengths.  They are short.  Not radar short at 24.0ghz but pretty short.  They are very directional and don't skip or go around things.  I think you are getting run down by local wifi use increasing when home owners get home and start binge watching Doctor Who.  Home's with cell phones increasing usage and opening up more channels when people are home from work?

That is logical, I havent considered that. I unfortuantly havent been using ham tech recently since I was needing it for an FPV model I was building but never got done. I remember the basics of ham, I just dont know everything.

JJBspark Posted at 2018-6-30 23:54
Hi,

This charts says enough....

What application did you use to get this analysis? (Beginner) Is there a basic step-by-step description of how to do this?

JJBspark Posted at 2018-7-3 23:47
HI,

Practise, practise and dont panic! Beacuse you cannot switch to ATTI on SPARK and MA no way to practise.

Wrong. The drone brakes and stabilises in ATTI mode as it does in P-GPS mode and will maintain height by using barometric sensors. The only difference between P-GPS mode and ATTI mode is that the drone won't stay in a static lat/long position in ATTI mode, it will drift around with the prevailing wind. In P-GPS mode, the drone will use GPS to maintain its position (height and lat/long).

gyrex Posted at 2018-7-4 06:59
Wrong. The drone brakes and stabilises in ATTI mode as it does in P-GPS mode and will maintain height by using barometric sensors. The only difference between P-GPS mode and ATTI mode is that the drone won't stay in a static lat/long position in ATTI mode, it will drift around with the prevailing wind. In P-GPS mode, the drone will use GPS to maintain its position (height and lat/long).

Hi gyrex, wrong :-)

But let`s wait for other members on this forum to react.
What i have read on here and experienced with non stabilized drones you  need to steer the oppose way to stop a movement.  If am i wrong, happy beacuse that means its easier to fly in ATTI.

cheers
JJB

grguthrie Posted at 2018-7-4 06:12
What application did you use to get this analysis? (Beginner) Is there a basic step-by-step description of how to do this?

Hi,

i use this > https://forum.dji.com/thread-145649-1-1.html

Step by step description, nah only if you can read/understand my program language.

cheers
JJB

gyrex Posted at 2018-7-4 06:59
Wrong. The drone brakes and stabilises in ATTI mode as it does in P-GPS mode and will maintain height by using barometric sensors. The only difference between P-GPS mode and ATTI mode is that the drone won't stay in a static lat/long position in ATTI mode, it will drift around with the prevailing wind. In P-GPS mode, the drone will use GPS to maintain its position (height and lat/long).

It will not brake.  ATTItude mode does not apply reverse thrust to stop motion.  The pilot needs to do that.  ATTItude mode just restricts max pitch and roll according to the IMU and returns to what it thinks is level when the sticks are centered.  Without a GPS, the ATTI would not know how much to brake or if the brake suddenly caused it to rocket off in the reverse direction.  

Does it need 5 seconds of braking from 30mph or 2 seconds from 15 to stop?  Hard reverse pitch or gentle revers pitch?  It wouldn't know.  Auto brake is only available with GPS.

The auto braking by the Spark in GPS drives me nuts.  I flew unstabilized RC helicopters and my fingers naturally want to apply reverse thrust themselves to stop the fast moving drone.  I couldn't get a smooth stop when I first started flying a drone (the spark) because of this.

HEATYBOB Posted at 2018-7-3 23:38
Hi Guys, another rookie here,just got a MA but still in box, so a biff question that will help me and hopefully other's, I fully understand the not taking off until the req no of Sat's are found,but imagine that in all the excitment of early flights many forget, so my question is if you forget and end up flying in ATTI mode then realise what's happening ,what's the best way to deal with the situation?

ATTI and OPTI work perfectly well if there are no external influences e.g. wind

Best place to practice is a local park or open space (grass landing are very forgiving) if you've a large room then you can practice inside (use the prop guards (read the manual on how to fit these and getting the drone to know they are fitted)) at your park or open space first practice Line Of Sight (LOS) flying, start by flying away and then back, then move on to fly away and then turn the drone 180 degrees and fly back (notice how the controls are reversed). Move on to flying in a square or loop, move on to flying using the camera etc.

Essentially learn how to fly the drone using LOS and the camera so that if you lose GPS you can recover the drone

Most common mistake is pushing left stick up to move forward or right stick left to go left when the drone is flying toward you (e.g. thinking the direction is relative to you not the drone).

Sorry to comment on such an old thread but the EXACT same thing happened to me last week except I was flying in bright daylight. The drone was no longer in my control and started moving sideways and crashed into a building... I was trying to stop it but it kept going! My drone died.. DJI better have some answers for this!

JJBspark Posted at 2018-6-30 23:54
Hi,

This charts says enough....

Very good MyCanIFlyCheckList.  Thanks, I'm going to use it.