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First (and almost) last flight of my MP!

ajoy

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Apr 25, 2017
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Location
Washington, DC, USA
I'm sharing the story of my first (and almost last!) flight of my MP up in Algonquin area in Canada; more as a note to myself than a caution to others about what could go wrong and how to not repeat my stupidity.

Last weekend, my nephew and I went up a small hill near Halliburton, ON to test out my shiny new Mavic pro. As we drove up the hill, I remarked to him that the tower somewhere at the mid point on the hill, looked like something we need to worry about if, "it is facing the same direction as we will be." - BIG mistake! Anyway, I did my entire pre-flight check, and even made sure that I can't even see the tower from where the drone was taking off (the other side of the hill). Despite that, it happened.

I did auto take off, hit 'RTH, precise position" the drone took off about 50-60M and presumably took a photo of the place and recorded the exact coordinates. We were airborne no more than 3 minutes when the craft started drifting towards the other side of the hill - on it's own! Within seconds of that - I am sure it started picking up even more noise from the tower - it headed off clear across the entire town of Halliburton!

To say that I was disappointed would be mild. I think the entire town may have heard my curses as the thing rapidly turned into a dot and disappeared. Thankfully, my 20yr old nephew has better eyesight and he said that he could still see the craft. When I tried to pull it up, he said he could see it respond. By then I knew it was the cell phone tower that was causing the issue so I kept it at about 200M (all this while the RC was showing full signal) and at a distance of about 800M - 1000M I kept hitting RTH. Again, my nephew confirmed that the craft was headed towards us. Within minutes, it landed a few feet from where it took off.

Lesson learned - never ever take the drone out if there is anything resembling a tower anywhere in the area! Period!!
 
Last edited:
Lesson learned - never ever take the drone out if there is anything resembling a tower anywhere in the area! Period!!
Interesting, I launch mine about 200 meters from a cell tower all the time. I have not had any issues like you describe. Upload your flight information I'm sure the experts will be able to give you some ideas on what happened and why.
 
And yet I've flown my MP and P4P within 100m of cell towers with no ill effect. Can you give me the lat/long of the tower - I can't find it in GE.

If the MP were being jammed, it would have RTH'd on its own.

How was the wind?

Can you upload the .TXT file to https://www.phantomhelp.com/LogViewer/Upload/ and Airdata UAV - Flight Data Analysis for Drones and various people here will take a look.

As an aside I suggest you review your RTH procedure. You don't need to do anything other than wait for the GPS to lock before takeoff. The home point will be set automatically.

RTH Setup Checklist

(And congrats on getting the MP back).
 
I too Fly my MP all the time at a park near me that sits on a hill with two water tanks and a big cell tower right next to the tanks. I have never had even a hiccup while flying there. At times I fly as close as 50 meters.
 
As an aside I suggest you review your RTH procedure. You don't need to do anything other than wait for the GPS to lock before takeoff. The home point will be set automatically.

RTH Setup Checklist

Wow! You guys are awesome. Will try and get the data off the craft. BTW, I noticed that I typed the distances in meters when it was in ft. I certainly did not fly at 200 meters high or a km from me.
 
Live in the big city of Lindsay Ontario kinda south east of ya and have tower about 1 km from me. I have buzzed all around I even used it as the poi and cicled it slowly just to see all the differ transponders that are on it. It is cell and Internet and cable tower. I have never had any problems with control. I am still using the .400 firmware been waiting for a better one but keep hearing stories of drifting on .550 and .600 firmware, the one after .400 made my video feedback not work very good started freezing very close to me. The .400 firmware I can go 4km away and video is rock solid
 
Still have not d/l the log files, but wanted to share this image with you all. Looks like there was some kind of interference that prevented image recording (I had not turned on video rec). I have two images like this within seconds of each other (subsequent images were fine) despite the drone just going crazy soon after this was shot.View media item 650
Notice that the image seems to have been cropped.
View media item 651
 
Thanks for the suggestion! I finally connected my phone to HD Sync and uploaded to airdata. Please take a look and let me know what I need to do to keep this from happening - Airdata UAV - Flight Data Analysis for Drones

Thank you all in advance!

Strange - I can't download your CSV/KML files for some reason (I am logged in under my account). Could you post the .TXT file to Dropbox and send the link please?
 
It's funny. I live in NYC. And have flown near cell towers pently of times. But I've heard this story before.
 
C'mon admit it, you were trying to draw Scooby Doo with your flight path. ;)

Just to chime in, I've flown within about 50 feet of a tower, to no ill effect.
 
Was able to examine the data and do online charts once I logged into my Google Account.

High Wind Warning at 161 s.

At 196.9 seconds " Aircraft is returning to the Home Point. Minimum RTH Altitude is 30m. You can reset the RTH Altitude "[1]
But to this point you had not even flown more than 10 metres away ...? You just climbed to 100 feet.

At 202.7 seconds, there is a "Current RTH route will pass a No-Fly zone. Pay attention to the aircraft's position to avoid RTH fai"
Enters Atti mode (no GPS). Begins to fly away with the wind.

At 204.1 there is "Magnetic Filed Interference. Exit P-GPS Mode". (Not my spelling error).
This happens right above the Home Point at 101 feet.
Was showing 20 sats at the time.
Nothing strange happens to the magnetic heading, however.

At 253. regains GPS - 674 feet from home. Heading begins to change (RTH I guess)

At 275 "Aircraft is returning to the Home Point. Minimum RTH Altitude is 30m. You can reset the RTH Altitude"[1]
Distance keeps increasing a bit (wind?) before beginning to reduce.

At 287.7 RTH is cancelled?
Distance increases.

At 1364 RTH starts again - distance 1364 feet.

Autolanding at the end with a pretty low battery.

Not sure why it dropped GPS. However there was a lot of solar activity raising the Kp in the 3rd week of April. May be related to that.

[1] I recommend you set the RTH altitude higher in the future - esp in hilly terrain or where there are known towers.
 
However there was a lot of solar activity raising the Kp in the 3rd week of April. May be related to that.

[1] I recommend you set the RTH altitude higher in the future

Holy cow!! Thanks for the systematic analysis and recommendation. I will set the RTH even higher than before. I thought I had set it up to be higher than the tallest tree on that hill, but obviously that was not enough to prevent interference. However, you are saying that that was possibly because of solar flares and not the tower?! Amazing! Thanks again.
 

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