Lost Phantom 4. Lost video and transmitter connection and it didn't auto RTH.

[pnobill88]

The situation was I had it comming back to me in P mode. It was about half way back working correctly. It was about 150 or 200 yards away and up about 150 feet. Suddenly I lost signal. I could still see the drone but it would not respond. Controller said weak signal. There was actually none. I kept trying to get it to come back. but couldn't send any signal. Video transmission was also lost. It wouldn't return on its own. I could see the paper airplane on the andriod screen pointing at a spot probably near it resting spot, maybe. After searching still no sign of it.

No GPS location on screen of bird or transmitter on P4. Happened to me before with my H502s. Both positions were on the tx and I walked to it in a couple of minutes.

I contacted DJI. We checked the flight data. I don't really know how to read it but it's DJI GO.
I have no vid, it's on the P4 sd. Is there some way I can use the flight data to help locate it. I didn't see and GPS co-ordinates.

Any help welcomed, of course.

In any event Happy Holidays!
Bill

 

[With The Birds]

What did DJI suggest, looked at flight data how? I'm confused, if you could see the AC in the air stationary you must have some idea where it came down?

Go to healthydrones.com and upload your flight log from your phone/tablet (instructions are on the website). Paste a link to the log here.

 

[pnobill88]

Dear With The Birds,

Thanks for the reply. I have to figure how to do that. DJI gave no suggestions. They just started a support tag.

shortly after: WOW!!! I didn't know all that was stored on the tablet!
Here's the link:
HealthyDrones.com - Innovative flight data analysis that matters

I also included an attachment log text file.

The area it says it landed, if accurate, is a Railroad property abandoned for over 40 years. It's overgrown, very difficult to get thru. Short trees, very tall wild grass, thick dense bushes, etc.

I tried looking with no luck. I'll give it another shot anyway.

Let me know what you think.

Thanks for your help,
Bill

 

[msinger]

You should look in the yellow area below. Your Phantom most likely crashed into one of those trees on its way back to the home point.

 

[msinger]

Were you able to find your Phantom?

 

[pnobill88]

Dear msinger,
We found the P4. Up 65 feet in the small branches of a tree.
I hired a tree guy with a bucket truck.

In a test flight it seemed OK. Battery seemed to charge OK. The video on the transmitter froze 4 or 5 times. I got it going again by rebooting DJI GO.

so far
Bill

 

[jopa489]

What was your RTH height set at? If it was not high enough to clear the trees, that could be a contributing factor to why it crashed. Glad you recovered it.


Sent from my iPhone using PhantomPilots

 

[pnobill88]

[height set at? If it was not high enough to clear the trees, that could be a contributing factor to why it crashed. Glad you recovered it.]

Thank you.

Sorry I left out a lot of the drama I had sent to DJI.

I went thru the DJI GO app online for 3 days before I flew it.
I was somewhat familiar with the controls because I have the HUBSAN H501s
and H502s, although they don't have all the safety features of course..

I left the RTH height at the default 30 meters. Plenty to clear anything around.
That was also notated on the flight record. The tree was not much higher than
65 feet.

Still waiting to see where I go from here.
Bill

 

[pnobill88]

Were you able to find your Phantom?

Dear msinger,
Since I found the P4 DJI had me return it to them. They gave me a free return
label. They said that was because it was still under warrenty.

Then I get this:

"You repair service of Phantom 4 has been quoted by our repair team. Please refer to the invoice below and complete your payment via paypal.

Invoice

DJI Care Balance：
Quote Date: 01-28-17
Remarks:
Item Quantity Unit Price（USD） Total Price（USD）
Phantom4 right landing gear component 1 10.00 10.00
Phantom 4 3-in-1 board component 1 189.00 189.00 (??? There was no damage on the outside of the P4)
Service Charge 2 65.00/H 130.00

Freight: 0.00
Total Amount: 329.00
DJI Care deduction：0.00
Total Payment: 329.00"

I told them not to repair it if the warrenty doesn't cover it, just return it to me.
I still think it was a product malfunction.

The repair seems too costly. I was wondering that if it was never found would they
have let me buy just a replacement drone only, since I still have every thing else.

It was a refurbished unit anyway. Just the replacement drone should not cost much
more than the repair and I would have the first one for parts.

I appreciate any thoughts.
Bill

 

[msinger]

I was wondering that if it was never found would they
have let me buy just a replacement drone only, since I still have every thing else.

I have seen them replace missing Phantoms a few times. That would not have happened in your case though since the crash was caused by pilot error.

 

[pnobill88]

I have seen them replace missing Phantoms a few times. That would not have happened in your case though since the crash was caused by pilot error.

Dear msinger,
No one has said anything to me about pilot error.
DJI has never mentioned anything either way.

I got the email from Fri night after they closed. I'll give them a call Mon
and see what they have to say.

I just checked in here so I'd something to go on when I contact them
beside my limited knowledge.

Thanks again for your help. I will post an update.
Hope this might help someone.
Bill

 

[Pachakuti]

From logs you provided:
"Warning Return-to-Home Altitude:98FT"
Now get a laser rangefinder and measure tree it caught.
If its less than 98 feets - its a hardware malfunction
Also your logs say:
"WarningGEO: You are in a Warning Zone (Class B Airspace). Fly with caution."
Did you fly with caution? Did you?
I'm not sure about signal loss, it may be blocked by something like jammer, which is pretty legit if you fly close by Airspaces, which is forbidden almost all over the globe

 

[msinger]

No one has said anything to me about pilot error.
DJI has never mentioned anything either way.

I guess they figured you knew it was caused by pilot error? I'm not sure.

Your log shows the following:

• You descended below the treeline causing RTH to be automatically initiated.
• While your Phantom was ascending to the RTH altitude, you hit the throttle stick. That caused it to return home at an altitude of 65 feet.
• You allowed the Phantom to return home at that altitude until it crashed into the trees.

 

[pnobill88]

From logs you provided:
"Warning Return-to-Home Altitude:98FT"
Now get a laser rangefinder and measure tree it caught.
If its less than 98 feets - its a hardware malfunction
Also your logs say:
"WarningGEO: You are in a Warning Zone (Class B Airspace). Fly with caution."
Did you fly with caution? Did you?
I'm not sure about signal loss, it may be blocked by something like jammer, which is pretty legit if you fly close by Airspaces, which is forbidden almost all over the globe

Had a clear view of the P4.

Here is a fly plan list of altitudes and signal errors. Started right from the beginning. Closest airport is Logan 10 miles away.

Download color coded Signal Strength KML

FliteTime/Alt / Home Distance/ Minor Signal Errors
A 00m 30s 8.5 ft 16 ft 22
B 01m 00s 7.5 ft 35 ft 16
C 01m 30s 8.5 ft 48 ft 11
D 02m 00s 10.8 ft 54 ft 16
E 02m 30s 17.1 ft 65 ft 8
F 03m 00s 391.4 ft 66 ft 12
G 03m 30s 392.1 ft 66 ft 25
H 04m 00s 392.7 ft 65 ft 21
I 04m 30s 392.4 ft 65 ft 16
J 05m 00s 392.4 ft 226 ft 29
K 05m 30s 393.4 ft 218 ft 61
L 06m 00s 392.7 ft 216 ft 73
M 06m 30s 391.1 ft 216 ft 36
N 07m 00s 290.4 ft 217 ft 57
O 07m 30s 270.7 ft 218 ft 50
P 08m 00s 284.4 ft 218 ft 22
Q 08m 30s 283.8 ft 219 ft 21
R 09m 00s 353.7 ft 219 ft 15
S 09m 30s 392.7 ft 217 ft 22
T 10m 00s 393.7 ft 397 ft 40
U 10m 30s 392.4 ft 865 ft 54
V 11m 00s 391.1 ft 866 ft 33
W 11m 30s 253.6 ft 835 ft 44
X 12m 00s 153.2 ft 739 ft 64
Y 12m 30s 158.1 ft 243 ft 20
Z 13m 00s 377.0 ft 97 ft 14
a 13m 30s 393.0 ft 98 ft 33
b 14m 00s 392.1 ft 561 ft 34
c 14m 30s 391.7 ft 931 ft 32
d 15m 00s 393.4 ft 1,059 ft 43
e 15m 30s 391.1 ft 1,061 ft 41
f 16m 00s 392.1 ft 1,060 ft 74
g 16m 30s 393.4 ft 1,060 ft 75
h 17m 00s 311.7 ft 1,061 ft 88
i 17m 37s 65.0 ft 1,153 ft 64

 

[msinger]

Had a clear view of the P4

You did for most of the flight. The view was not clear near the end when RTH was auto initiated though. Your Phantom was definitely below the treeline.

 

[pnobill88]

You did for most of the flight. The view was not clear near the end when RTH was auto initiated though. Your Phantom was definitely below the treeline.

Dear msinger,
Thank you for your help. I really want to find the cause so I can fly without worrying. I got a Mavic two weeks ago and still haven't flown it yet.

I had clear line of sight of it hovering at over 300 feet from 15m 00s until 17m 00s when it apparently went into RTH. I had clear sight of it when it went into
RTH until it dropped down shortly before hitting the tree.
I had lost complete tablet and transmitter signal before it started hovering.

I was well outside the 5 miles of an airport but I did some searching and found
out Logan has a larger class B area, an 8 or 10 mile radius. I was within the perimeter by about 2000 feet.

I never got any explanation from DJI about the cause except they said it was my fault. I paid for the repair and am waiting for its return. I did send DJI support an email asking for an explantion.

b 14m 00s 392.1 ft 561 ft
c 14m 30s 391.7 ft 931 ft
d 15m 00s 393.4 ft 1,059 ft
e 15m 30s 391.1 ft 1,061 ft
f 16m 00s 392.1 ft 1,060 ft
g 16m 30s 393.4 ft 1,060 ft
h 17m 00s 311.7 ft 1,061 ft
i 17m 37s 65.0 ft 1,153 ft

Here are some links to the locations to see the trees:

About where it was hovering. The trail starts on the left between the building and the cars.
Google Maps

Here's a view of the treeline in the back. Notice the cemetary shed in back on right.
Google Maps

This is an arial view of the crash location. If you draw a line from the lighter colored cemetary shed on the right, to the corner of Auburn St the tree is the one right on the trail on the near side.
Google Maps

 

[msinger]

I had clear line of sight of it hovering at over 300 feet from 15m 00s until 17m 00s when it apparently went into RTH. I had clear sight of it when it went into
RTH until it dropped down shortly before hitting the tree.

Between 16m 52s (blue circle below) and 17m 26.1s (yellow circle below), you had the throttle in the full down position. That caused your Phantom to descend from an altitude of 393 feet to 47 feet. At that low altitude, you no longer had a clear line of sight.

To recover from this situation, you could have disabled RTH as soon as your Phantom started returning home. Instead, you let it continue to automatically return until it crashed into the trees.

 

[F3honda4me]

Between 16m 52s (blue circle below) and 17m 26.1s (yellow circle below), you had the throttle in the full down position. That caused your Phantom to descend from an altitude of 393 feet to 47 feet. At that low altitude, you no longer had a clear line of sight.

View attachment 75539


To recover from this situation, you could have disabled RTH as soon as your Phantom started returning home. Instead, you let it continue to automatically return until it crashed into the trees.

Msinger is 100% correct. The aircraft was at 393 feet. You commanded the aircraft down to 47 feet by holding throttle down. At that point it lost signal, and at some point the RC reconnected to the craft while the craft was ascending to RTH height of 98 feet. This occurred at 65 feet. At this time you also hit the throttle stick down, whether on purpose or unintentional or you didn't realize. But this is in the logs so it absolutely happened. This caused the craft to stop ascending for RTH per the manual. It then will RTH at this height, in your case about 65 feet.

DJI would have seen this in the log inside the craft which is why they sent you the bill.

 

[AWD]

Very nice work, guys.

AD

 

[pnobill88]

WOW!!!
Thanks for your help! I'd like to find out were the flight record of the
included relative heights draw in can be located.

You guys are right on the money. The yellow circle is where I
lost sight of it. I very likely pulled the throttle down and probably
more than once. Since I had lost all feedback from the P4
I was trying anything figuring it had no effect anyway, and
had nothing to lose.

Even tho' the controller and tablet said they had no contact
near the end, when I came home someone here mentioned to check the
flight path on the tablet. I didn't expect to find anything,
but I had the whole flight record and final video into the tree.
It obviously was still in some contact. Surprising.

I would still like to find out why I lost contact in the first place
to avoid doing it again.

At least I'm getting a little education (facinating)
and this incident never really bothered me much,
even as I watched it disappear.
I spend much more time moding and fixing my
other quads than I do flying them, by far. It's all fun.

At 65 I can't play tackle football as often anymore
so this keeps me occupied sometimes.

Gratefully,
Bill