crashed into power line

[BarrySDCA]

I experienced an interesting crash today with the Mavic Pro Platinum. I have these high tension power lines in front of my house a bit out towards the lagoon. I know from numerous previous flights between this and a Phantom copter that if I pass over it 60' up, I have plenty of clearance. They are down a bit and I'm up on top of a canyon.

I upgraded the firmware just yesterday. I was coming in at 69 feet and ran right into the top most wire. Lost 4 props but copter seems ok.

I didn't re-calibrate anything after the firmware update. I'm thinking I probably should have. I can post a video later if there is any interest.

Just wanted to post this heads up because of the firmware update yesterday. Many flights back 60 feet no problem and at 69 feet I hit the 1/2" thick wire. ****....

 

[msinger]

I upgraded the firmware just yesterday.

That likely had nothing to do with your problem. It would not be unusual for the altitude to be off by 9 feet between different flights. The altitude is estimated and one should never assume it's the actual altitude.

 

[Former Member]

It could have been a problem after the firmware update. I have heard of this happening before.The IMU has an electronic barometric altimeter, and if it is off even 10%, at 69 feet, it would be 7 feet off, thus your problem. If your MPP is still in one piece, you might calibrate the IMU and then see how high the power lines are.

To check whther or not the altimeter is accurate, just get a yardstick, place it on the ground sticking up. Stick your Mavic on top Motors and props off) and see if it reads 3' altitude. That will also tell you if your ground sensors are accurate.

BTW, do you have any other drones you can check the elevation of the power lines with?

 

[BarrySDCA]

My previous drone was an old phantom 2 and dropped from the sky a couple years ago after I put a new battery from china in it. doh!

In regards to this crash, it most certainly is my fault as the buck stops here. I get that. But something is very off. 60' has historically been PLENTY of clearance over the top wire with this done and the one before it. It's a little deceiving looking at it as it's flying in, sort of an illusion trying to figure out if it's going to hit. So I've become comfortable knowing 60' and I'm golden - easily. Not yesterday, 69' was right on that top wire. I got a good closeup of it hah. I can post it later. the copter *almost* recovered on the way down but it had a good chunk out of one of the propellers and so it didn't have much lift there. it was still sending video and that helped find it from a unique red flower in the neighbors yard.

In regards to the elevation being off after the upgrade, that could very well be the case. But it seems to be the other way. Or maybe it's just malfunctioning in general. I did notice yesterday it said .3 feet off the ground when it was more than 3 feet. This all since the last firmware upgrade. That's really the only thing that has changed. Since the crash I re calibrated the IMU and compass but have not tested the elevation accuracy just yet.