From: Jobe Costa
Received: 2018/2/1 23:53
To: DJI repair dept; DJI Service Dept; DJI Service Dept; DJI Support_US; support.usDJI
Subject: RE: CAS-1440463-P3P7Y1 CRM:0409000000652

  

The wind speed for Thornton, Colorado on January 15th 2018 was 6-10 mph which is less than 4.5 m/s.  The attitude and horizontal speed was due to the aircraft being under power without input from the pilot of the aircraft.  It was not raining, snowing and there was not any fog.  I am considering posting your findings to social media to warn potential customers of your lack of responsibility for you product.  I read many reviews prior to purchasing this product.  Since the incident, I have found several reviews stating the “fly away” issue is more prominent than it should be.  I am only asking for a replacement drone and battery.  I have spent extra money on extra accessories from DJI for the drone which I am not requesting reimbursement for.  If I were to be negligent in the piloting of the aircraft, I would not be corresponding with your company.  I would handle the issue on my own.  Please reconsider your findings taking in to account the lack of wind, weather and pilot error.  The aircraft traveled 520 m in 146 seconds according to you findings.  That means the wind was at 3.56 m/s which is well below your stated 10 m/s flying condition warning.

  

  

Jobe Costa

Dear Jobe,  Many thanks for your kind reply. Sincerely sorry for the late reply.  As I have stated in my last reply, the wind speed that shows in the broadcast is the speed of near ground wind, but it doesn't indicate the wind velocity that the aircraft suffers in high air. The higher the aircraft was, the stronger wind it would experience, not to mention that the relative height of the aircraft was over 180 meters. From the attitude and the speed of the aircraft, we could check that the aircraft was under the influence of the wind from northwest and was the home point direction. Due to the wind, the aircraft could return back to the home point at full speed and was blown away. We have reviewed the flight record again but only to find that the previous conclusion still stands. The incident was caused by piloting the aircraft under high-wind condition and it was the pilot's responsibility to fly in safe and proper environment.  We confirmed with our supervisor and determined that your case couldn't be covered under warranty, and the 15% off discount is already the best offer we could apply. Please consider it and reply to us if you need it. Although we don't expect it if you want to take any legal action, but we respect your decision. The 15% off discount will be valid for one month, please reply this E-mail if you need it.

Dear Jobe,

Thanks for getting back to us.

As we have stated in the user manual, please do not use the aircraft in severe weather conditions. These include wind speeds exceeding 10 m/s, snow, rain, fog and so on.

The wind speed that shows in the broadcast is the speed of near ground wind, but it doesn't indicate the wind velocity that the aircraft suffers in high air. The higher the aircraft was, the stronger wind it would experience. From the attitude of the aircraft, we could verify that it suffered from the wind. We were not able to check the real weather at your area, but the result was judged from the attitude of the aircraft based on the flight record.
Moreover, the aircraft itself didn't have an internal senor to measure the wind velocity. It couldn't detect the exact wind speed by itself, instead, it checked the wind velocity according to its attitude and horizontal speed. When the aircraft tilted itself to abnormal angle without any pilot's input, the warning of high wind would appeared on the APP to remind the customer. When the notice popped up, we mostly suggest the pilot to land or lower the aircraft rather than to keep it flying.
We are sorry about the frustrating experience you have had. We assure you we do not deliver this news lightly and we have carefully examined your case. We know this is disappointing but although we cannot find any product malfunctions or defects and it remains non warranty, the 15% off is a courtesy to try to assist in any way we can.

Thank you so much for your support. Have a nice day.


Best Regards,

Dora
DJI Tech Support

What was the rate of the wind during flight?  At what rate should the drone not be operated?  As you can see from the data, the drone was under power when it flew away from me.  The last GPS location was 2700’ away from me and the home location.  That can’t be from it being windy.  That means the drone was flying under power which means a malfunction in the equipment.  I have read several accounts of this happening by other DJI users.  I am very disappointed in DJI’s findings.  I have spent a considerable amount of money to use your product and I do not feel satisfied with the outcome of the investigation.  Please respond at you convenience.  Thank you.

Hi Jobe,


Thanks for your patience.

For your claimed case CAS-1440463-P3P7Y1, we have already finished the analysis, and the result is as follows:

1. The aircraft was working in GPS mode after it took off, the aircraft was affected by the wind from northwest during the flight;
2. At T=01:50, H=199 m, D=213.4 m, the aircraft tilted 15.9 forward without any pilot's input, which indicated that there was wind from northwest affecting the aircraft;
3. At T=04:03, H=181 m, D=715.9 m, Failsafe RTH was triggered, but the aircraft couldn't return back home normally due to the wind from northwest;
4. At T=04:16, H=181 m, D=734.1 m, the flight record ended.

According to the analysis, the incident happened due to piloting the aircraft under improper environment. Please do not fly in high-wind condition.

We greatly appreciate your support for DJI, and especially applied a 15% off discounted coupon code for Phantom 3 Standard without charger and remote, which could be used when you arrange payment for an order on DJI online store:

It's better than nothing.  If you want another, I would accept their offer.  lucky that you weren't fling a P4P and lost $1500.

If you decide to purchase another DJI product or not, I would advise purchasing a program called UAV forecast. UAV forcast not only tells you the wind speed at the altitude you will be flying but also supplies a lot of other useful information before taking flight. This app has stopped me from flying a few times when wind speed on the ground was 10mph, but showed at my flying height 375' wind speed at 25mph.

Worldwide you can use
https://earth.nullschool.net

You can see all kinds of wind flows, at what hights and wind speed around the whole world.
Luck

Another really good website for the weather, ventusky

If you'd like, upload your log to

http://www.phantomhelp.com/LogViewer/Upload/

...and then paste the link here.  Somebody will look at it and give you their honest assessment.  

Thornton, Colorado on  January 15th 2018, wind gust speeds aloft @ 25mph to 35mph?

DJI won't buckle no matter what you try to prove to them. Only thing you could do is grab some insurance on the drone prior to flying them.

https://www.reddit.com/r/dji/com ... _rth_rc_disconnect/

JC351 Posted at 2018-2-5 06:30
What was the rate of the wind during flight?  At what rate should the drone not be operated?  As you can see from the data, the drone was under power when it flew away from me.  The last GPS location was 2700’ away from me and the home location.  That can’t be from it being windy.  That means the drone was flying under power which means a malfunction in the equipment.  I have read several accounts of this happening by other DJI users.  I am very disappointed in DJI’s findings.  I have spent a considerable amount of money to use your product and I do not feel satisfied with the outcome of the investigation.  Please respond at you convenience.  Thank you.

I could ask for flight data to analyse but there is enough information in DJI's response (post #5) to see that this is simply another case of someone flying high and downwind in strong wind conditions and being surprised to find that their drone didn't return.
We see similar cases every week.
This is not the fault of DJI and is 100% attributable to the way the Phantom was operated.
Your Phantom isn't magic and is affected by strong winds.
The winds are always much stronger up high than what you experience on the ground.

The flyer needs to understand how the Phantom works and how to operate it properly if they want to bring it home every flight.
RTH is a slow driver. It cruises at 22 mph but you can drive at 36 mph (still air speeds).
If the Phantom is trying to push against a wind stronger than 22 mph, it's going to be blown backwards until battery level triggers autolanding

It's very important to be aware of wind strength and direction.
Note how much the wind slows your Phantom if you try to fly directly into it.
Never fly away downwind in a strong wind situation - you will have a tough headwind to fight to get back home.
Never leave your Phantom up high fighting a headwind. Bring it down where the wind is less.

Hi Jobe, we are sorry for your loss, but Dora has explained very clearly in the email, the higher the aircraft was, the stronger wind it would experience. Per the flight records, the aircraft tilted 15.9 forward without any pilot's input, which indicated that there was wind from northwest affecting the aircraft, the drone failed to return home because of the strong wind and we never recommended to fly the drone in strong windy weather, appreciate your kind understanding.