Is this actually what the problem was? Did my drone go down because it was flying directly beneath my feet under a bridge?

[MS Coast]

Looking at the video, the drone was being flown sideways very close to the left hand side of the span and collided with the the rock. Here are two screen clips. Just prior to impact, the drone rolled slightly left and accelerated a bit, and then rolled back level. That would be consistent with a left motion on the left stick. The flight log would show that.

If you must fly under a bridge, it would seem advisable to choose a path near the centerline of the span and fly straight ahead so that the collision avoidance system is effective.

 

[Yorkshire_Pud]

Oh blimey I missed post no5 and the video sorry.

 

[Starz]

I would bet $$ that this is not a loss of signal.
Aircraft was fine until it was turned to the right and flying sideways.
My 2 cents.

 

[nowtleft]

You clearly don't understand how radio frequency energy at microwave frequencies work. Neither GPS signals nor WiFi control signals can penetrate all the steel that is likely to be in a large bridge, and both are essentially line-of-sight unless you're lucky enough to get reflections from surroundings. So no, there is no reason to expect either to work 15' below you when standing on a bridge.

Whether or not any of that is "common knowledge" is questionable, though. You aren't alone based upon many other posts I've seen on these forums.

I bow t your superior knowledge

 

[nowtleft]

I entirely agree, that it hit a side wall, as a newbie I could be wrong, but i've years of experience flying R/C helicopters, and only judging with what i've seen, as it passes under the bridge line of sight lost, big mistake, but sorry about your loss.

But I could see where I was going in the goggles. I was flying to the middle to turn left to head upstream. The drone did the opposite of what it should have done.

 

[Yorkshire_Pud]

Where was the video recorded, in the goggles or in the drone?
I seem to remember that the goggles can record video but if that is correct I have no idea if they record solely the camera view or if it records the view seen by your eyes in the goggles which includes telemetry.

If the video is from the goggles then the logs will cover the same period of time as is shown in the video and show what commands the drone 'thinks' you gave.
To me it seems that once the drone was level or past that outcrop of rock on the left it started to move left, initially slowly with very little tilt but then significant tilt/speed.
I am wondering if you confused "turn left" with "move left", the logs will tell us if the drone 'thinks' you gave a "move left"command and the status of the GPS and what flight mode the drone was in.

 

[Rich QR]

But I could see where I was going in the goggles. I was flying to the middle to turn left to head upstream. The drone did the opposite of what it should have done.

If you could see where you were going in the goggles, that's a suggestion that communication between the controller and drone wasn't blocked.

I've seen the video, and clearly you were flying beneath a thick stone bridge which would block GPS, and you were above moving water, which would make the downward vision sensors useless.

Our drones fly with amazing stability when GPS or downward vision sensors can stabilize them. Take your hands off the sticks and the drone hovers. Move the right stick a bit to the right or left, or forward or backward, and the drone moves likewise. You don't have to concern yourself with minor breezes. It's all thanks to the magic of the GPS-stabilized IMU and the control software on board.

But when you deprive the drone of GPS signal, the drone suddenly starts relying on YOU to manually do the corrections for wind drift. It has no reference for what constitutes "stationary". It will not brake when the sticks are returned to the neutral position. As the wind currents swirl underneath the bridge, you must immediately move the sticks in the proper amount to precisely counteract any drifting tendency.

The drone may have been moving left when you were moving the stick right, but that would merely indicate that you hadn't moved the stick far enough right to counteract the wind that was pushing it leftward. It's very tricky to get precisely the right amount of stick movement to counteract the wind drift. Even more so when you can't clearly and directly observe the drone. It takes a lot of practice.

If you're going to fly the drone where it can't see GPS and can't clearly see stable ground within the vision sensors' range, I'd suggest first practicing with a cheap toy drone that lacks GPS and vision sensors. The cheapest, smallest toy drones are good for this sort of practice (and not good for very much more). When you can effortlessly fly one in varying winds outdoors, you're ready to fly under that bridge. Until then, keep clear skies above.

 

[Lets Fly]

My guess is that it hit a side wall.

Exactly, mine also.

 

[Yorkshire_Pud]

Please just post the flight log, it will probably answer an awful lot of questions



BTW did you have a spotter with you i.e. a person who had line of sight on/with the drone?
I do not see anyone else

 

[FLDave]

@nowtleft Since you were not able to maintain VLOS with your FPV googles what did your required visual observer see. Your visual observer should have been able to warn you.

 

[Starz]

There is no evidence of an observer along with no evidence of wind in the provided video. Without the report from DJI and or the flight log, this is ALL speculation at best. Chastising the op for how this flight should have taken place will probably not change the outcome for this flight. We learn from our mistakes because we are human and my guess is there were a few lessons learned here.

 

[wardtom084]

I fly my drone as if I had my family on the thing. I am sure you would not be taking yours under a bridge. If more people would do this there would be less crashes. Take a look at a topic called risk management in the 107 class.

 

[Gringorio]

I fly my drone as if I had my family on the thing. I am sure you would not be taking yours under a bridge. If more people would do this there would be less crashes. Take a look at a topic called risk management in the 107 class.

Taking calculated risks, and even crashing, is part of becoming a better drone operator. Capturing important or unique shots often takes risks. Taking risks grows skill levels and teaches limits. Note I'm not suggesting reckless flying.

 

[DRM001]

Watching the video all I see is a nervous beginner pilot and props hitting the wall.

Don’t need the flight logs to see this has nothing to do with loss of GPS and everything to do with pilot error.

 

[graywoulf]

That drone hit the rocks just before getting to the bridge. It never made it to the underside of the bridge at all. The TikTok video proves that.

 

[graywoulf]

That drone hit the rocks just before getting to the underside of the bridge. That TikTok video proves that. Sorry to say but it appears to be pilot error in this case.

 

[Yorkshire_Pud]

Don’t need the flight logs to see this has nothing to do with loss of GPS and everything to do with pilot error.

BUT..........we do not know if the sideways movement was commanded or uncommanded.
I suspect it was commanded but.......innocent until proven guilty, the evidence lies in the log. Since I have an FPV I, for one, would like to know the answer to that.
But I guess we will never know.

 

[Starz]

That drone hit the rocks just before getting to the bridge. It never made it to the underside of the bridge at all. The TikTok video proves that.

And this is a good example how far past reality things can get.
The video CLEARLY shows where the crash occurs and it is under said bridge.

 

[graywoulf]

And this is a good example how far past reality things can get.
The video CLEARLY show where the crash occurs and it is under said bridge.

OK, I stand corrected per the previous posted still shots from the video by MS Coast. But it still hit the rocks that it was flying too close to.

 

[Jamesz]

The only time I tried flying under a bridge a immediately started getting magnetic interference and even went into atti mode.
I quickly realized what was happening and was fortunate to get under control once away from bridge…
It affected my compass resulting in a near crash.
I fly a Mavic Pro btw..
Maybe that will shed new light

Magnetic interference from the bridge would be unlikely to cause loss of contol as the IMU is doing most of the management, the compass is only of primary importance at start up, where it provides the IMU with its reference heading. The real cause would be loss of GPS signal, hence ATTI mode, not magnetic interference.