DJI does not stay behind their product when it comes to crash even though. Their technical service is the worse service ever. They never accept their mistake on their products and they are making fun of their customers with their explanation. Why are we buying these drones? To take unique pictures and drones, right? In my case, I was flying my DJI Phantom 4 Pro drone 2-3 meters above the water level on a river. I was only pushing the joystick forward and when I was passing under a bridge, I lost the signal from the drone for 1-2 seconds. Meanwhile, I lost the camera screen, as well. After 1-2 seconds, when the camera screen reappeared on my screen, I saw a sudden decrease in altitude, it was about to hit the water. Maybe it did because after 2-3 seconds I lost the camera screen again and never came out again, and I increased the altitude immediately when I saw that it was hitting the water. I could not control the drone properly right after that. There was something going on. The flight mode was changed by itself. The camera screen on the phone was gone. Since I did not have the camera screen on my phone, I did not know where exactly the drone was and where it was facing to. When I increased the drone altitude immediately up to 7-8 meters. I could not visually see the drone’s position exactly because there was no image on my screen and the drone was about 300 meters away. I could see the drone, However,  I was not sure about if the drone was under the bridge or just passed the bridge. After a while it gave a missing propeller error and then I lost the signal of the drone. It fell into the river and I could not find it. I think the drone’s down sensor did not work properly or something was working wrong because it did not give me any notification until it hit the water even though I did not push down the left stick to descend it. Normally, during the flight even if it is tried to descend the drone very close to ground level, the drone does not allow to get so close to the ground very quickly, it normally slows down for landing due to the censors. Luckily, I was recording a video when this happened. I attached it here, as well. https://www.youtube.com/watch?v=H6GhpRaFDCA&feature=youtu.be


I have sent them the video footage and flight logs. After that, there is a lady in the technical service, and her explanation about the crash is:


Firstly, please be noted that the analysis is aiming at figure out the cause of the incident, and the state of your aircraft after the crash was not the vital part of the result. According to your record, the aircraft did not switch to Atti mode by itself but entered OPTI mode at t=12-33 because the aircraft was flying under the bridge and the GPS signal was blocked.


Secondly, the reason why the aircraft hit the water was that the performance of the Vision System was affected by the surface being flown over. Ultrasonic sensors may not able to accurately measure distances when operating above sound-absorbing materials such as flying over water or transparent surfaces. And that's why your aircraft would not hover above the water.


Thirdly, please do not ignore the Flight Environment Requirements in Manual users, please refer to page 53: https://dl.djicdn.com/downloads/ ... _User_Manual_EN.pdf


It requires the aircraft ONLY fly in open areas. Because the obstacles like tall buildings/trees/bridges would block the GPS signal, which may lead to incident like this case.


The biggest reason for the crash was not losing the camera screen on the phone but the improper flight environment.


We greatly appreciate your support for DJI.


If you consider purchasing another aircraft, we can try to especially apply for a 15% off coupon code which could be used on DJI online store for Phantom 4 Pro without charger and remote:
http://store.dji.com/product/phantom-4-pro-aircraft-excludes-remote-controller-and-battery-charger


Please email me if you want the coupon code ready, for example: “I accept the offer”. Thanks a lot.


Have a nice day.




Best Regards,


Evelyn
DJI Tech Support
http://www.dji.com/


As a human being, without your eyes and seeing anything, could you go home without any help? This is exactly what happened with my drone. How come are you saying that losing the vision system was not the vital part of the accident? How could you come up with this opinion? Are you the decision maker? The thing that would not be important for you would be the most important thing for other people. When it comes to crash or incident, they never stay behind their products.
In Phantom 4 pro manual, it does not say that you can not fly under the bridge, there is no restriction about that.  They are telling me that you can not fly it over water surface or between the tall buildings. However, if you watch their Phantom 4 pro introducing video, they tempt and attract people to buy their drone flying over the water surface and between tall buildings, near the hot lava and cold places, which are not convenient flight environment according to their explanation and manual. Nobody is reading flight manual before they buy the drone. Otherwise, there would not be any purpose of the advertisement. Big controversy and conflict. They just want me to accept their 15% off for next purchase, which is a big joke. I already have 10% student discount. Moreover, why should I buy your product again, It is gonna hit somewhere else and I will lose another 1500$. They think that it is very little amount of money, and everybody can afford it. They are just making fun of with me with their super kind offer. They do not know what does that mean to them when they lost something worth 1500$.



DJI is misleading its customers with its Phantom 4 Pro advertisements. and DJI encourages its customers to fly in these areas, which we are told not to fly in these areas as you stated in your crash explanation. And, it is mostly resulted with a crash or losing the aircraft because of your wrong and misleading advertisements. Thus, your explanation and the advertisement of your product do not overlap, which is a big conflict, and this is very obvious when you watch the Phantom 4 Pro introducing the video.    https://www.youtube.com/watch?v=ZVNO-fib6fg

Unfortunately this appears to be yet another case of a customer who does not understand how to fly his aircraft and refuses to accept that the loss of the aircraft was his fault.

Simply put you DO NOT FLY UNDER BRIDGES. There have been many people come onto this forum and complain about the loss of their aircraft when they flew it under a bridge. Correct, they do not tell you in the manual not to fly under bridges, but they don't tell you not to fly in lots of dangerous situations, that's your job as a pilot to work out. The aircraft is a complex technical device and has certain limitations and the important one here is that under a bridge you will lose GPS reception, and that causes the aircraft to go into ATTI or manual flight mode. You do not appear to know this, but there would have been a warning on the screen saying it was in ATTI mode.

It also appears you lost the video feed from the aircraft as well, which is also not surprising. And by your own admission you could not see the aircraft properly. Your words: "However,  I was not sure about if the drone was under the bridge or just passed the bridge. After a while it gave a missing propeller error and then I lost the signal of the drone. It fell into the river and I could not find it."

You also said you tried to make the aircraft climb, so it is a fair bet you could have flown it into the underside of the bridge and broken a prop. After that it fell into the river.

Seguner, you forgot to attach the case number here.
I think Evelyn has explained clearly in the email. Though we didn't state precisely that the drone cannot fly under bridge, we do have state that ''Only fly in open areas. Tall structures and large metal structures may affect the accuracy of the on-board compass and GPS system''. The GPS was blocked under bridge and the vision system was affected because the drone was flying above water. So the drone failed to hover.
The drone can fly in ATTI mode, but it needs be controlled by professional pilot with rich experience because the drone will not hover steadily. We still suggest customers fly the drone in open area for safety flight.
We are sorry for crash accident.