Welcome Mavic Pilot!
Jump in and join our free DJI Mavic community today!
Sign up

Heartbreaking crash! And some good news...

Joined
Jul 26, 2018
Messages
17
Likes
11
Age
42
#1
Hi everyone! I'm new to the Mavic Pro, and now I'm going to learn how to repair one that crashed from 400 feet. I was enjoying some evening flying, and ran her up to 400 feet to avoid annoying the neighbors while getting some cool sunset pictures. I decided to fly off a thousand feet over a neighboring corn field to get a better perspective on our lake.

As I was nearing 700 feet from home (and out of sight due to some trees) I was annoyed by the slow progress I was making. Due to a breeze the Mavic was only making 12 mph. So I decided to see if Sport mode would help. While cruising max forward I used my index finger to click the mode switch to Sport.

Bad idea apparently. It immediately doubled over and began spiraling to the ground. I released all control inputs assuming that it would right itself....still spinning...so I quickly switched back out of Sport mode....no help. After a few more seconds of spinning blur the controller lost connection and I was in shock. I've only flown this thing a few hours, and had no idea this could happen. That's why I bought the Mavic, so I could rely on its gyros and RTH features to avoid unnecessary crashing! How was I ever going to find my Mavic in that massive corn field?

Luckily a few minutes later I got a distress call from my downed bird. The controller regained a connection, and I saw dirt and shredded corn leaves on the screen. I grabbed my boots and followed the map to where it should be. I stopped and heard the cooling fan running in the distance! After clawing through the corn a little ways further in the direction of the the sound I saw a pitiful sight.

She was alive, but badly damaged. The gimbal and camera was hanging by a wire. Only one prop was broken, but both rear arms were rotated up 20 degrees further than they should be able to go. The one front arm was fine, the other has essentially a dislocated shoulder, and both have broken landing gear. And mud is packed in the motors, and pretty much everywhere else. But her heart was beating, and the lights were on. I sadly pressed her button, powered her down, removed the battery, and placed her in a medically induced coma. Still... Not bad for a 400 foot fall. I'd probably look a lot worse.

So what went wrong? I guess flipping to Sport mode while flying max forward was too much for the stability control to handle, but then why couldn't it recover? I want to learn from this so that it doesn't happen again. In the mean time, I need to scrub in for a several hour surgery.....
 

Cyberpower678

Well-Known Member
Joined
Jan 11, 2017
Messages
3,933
Likes
1,737
#3
Something is fishy here. It’s not flipping the switch is activating a turbo jet rocket. All sport mode does is ramp up the power to the motors and increases the pitch. I’ve done this lots of times. Something must have hit the drone.
 

jaysrmc

Well-Known Member
Joined
Jan 2, 2018
Messages
515
Likes
227
Location
Phoenix
#4
Something is fishy here. It’s not flipping the switch is activating a turbo jet rocket. All sport mode does is ramp up the power to the motors and increases the pitch. I’ve done this lots of times. Something must have hit the drone.
I agree it's just not how sports mode works... Now if you were low to the ground or to some type of trees and hit sports mode, I could see the pitch change causing you to hit something pretty quickly, I have done that flying low to the ground but with gimbal cover on so I didn't break anything.
 
Likes: daasmangi
Joined
Jul 26, 2018
Messages
17
Likes
11
Age
42
#5
I'll upload the txt log file. Let me know if you need something different. The website mentioned in the instructions you posted does a good job of displaying the data, but none of the download options look very readable. So I'm uploading the original.

Looks like it immediately decelerated to nearly stopped as soon as Sport mode was engaged.....could be because I released the controls as soon as I saw spinning, but then it began spiraling down and lost 400 feet in 6.5 seconds.
 

Attachments

Last edited:
Joined
Jul 26, 2018
Messages
17
Likes
11
Age
42
#8
It sounds to me like you might have lost a prop that was improperly engaged in the motor hub. The sudden increase in power could have dislodged it.
I wondered about that, but I did check them before flight, and had been flying for 20 minutes on a previous battery before this short flight. Prop failure maybe?

According to the log file it was flying smoothly, but within 1 second of Sport mode being engaged, it had yawed around 180 degrees and never stopped spinning till it hit the ground, along with dramatic pitch and roll oscillations as well.
 
Likes: Gut Stuff
Joined
Jul 26, 2018
Messages
17
Likes
11
Age
42
#9
This is what's left of the one missing prop, which I could not find at the crash site. Hub still attached to the motor.

Prop failure almost certainly...triggered for whatever reason by the additional load as it engaged in Sport mode.

The others are intact and unbroken.
 
Last edited:
Likes: WAXMAN
Joined
Jul 26, 2018
Messages
17
Likes
11
Age
42
#11
If you can attach the DAT file, there are a few Mavic-whisperers here who might be able to tell you if the prop failed before or after the crash.
I'll try to figure out how to get the DAT file off the Mavic in the morning. Good idea.
 

Randy

Well-Known Member
Joined
Oct 28, 2016
Messages
159
Likes
47
Location
Alaska
Website
www.fortymileair.com
#13
Something is fishy here. It’s not flipping the switch is activating a turbo jet rocket. All sport mode does is ramp up the power to the motors and increases the pitch. I’ve done this lots of times. Something must have hit the drone.
I remember getting a “do’s and dont’s for Mavic owners” email from DJI sometime in the last year about flipping into or out of sports mode while in motion and it was highly discouraged.
 

N422BH

New Member
Joined
Jun 4, 2018
Messages
2
Likes
3
Age
52
#14
Sport mode is the devil. I crashed mine into a pine tree at 40mph, then watched it hit every limb on the tree on the way down. Never went back to sport mode again. I got lucky it missed the lens by a mm if that, just a busted viberation pad hoop thingie. Took few hrs to fix but never to return to sport mode.
 
Joined
Jul 26, 2018
Messages
17
Likes
11
Age
42
#15
This is the DAT file from my phone. I'm afraid to power up the Mavic in its current condition to get the DAT file off of it directly. I want to get the mud out of the motors first, and disconnect the gimbal. This file is not a real ZIP. I renamed it because the forum blocked me from uploading a DAT. Just rename it with a DAT extension. I have no idea how to decode it. If anyone finds anything that indicates something other than a prop failure, I'd be greatful to know about it.
 

Attachments

BudWalker

Well-Known Member
Joined
Oct 24, 2016
Messages
1,067
Likes
582
Age
70
Location
Santa Margarita, California
Website
www.datfile.net
#16
This is the DAT file from my phone. I'm afraid to power up the Mavic in its current condition to get the DAT file off of it directly. I want to get the mud out of the motors first, and disconnect the gimbal. This file is not a real ZIP. I renamed it because the forum blocked me from uploading a DAT. Just rename it with a DAT extension. I have no idea how to decode it. If anyone finds anything that indicates something other than a prop failure, I'd be greatful to know about it.
The .txt shows Sport starting at 118 secs. And, then the .DAT shows what appears to be a leftBack prop failure at 118.712 secs (about 0.7 secs after Sport mode was initiated). The leftBack speed increases in an attempt to produce more thrust from the failed prop. Concurrently, the rightFront speed decreases to match the lower thrust from the leftBack prop.
upload_2018-7-27_18-6-6.png

The CCW rotation that then occurred is consistent with prop loss on either the leftBack or rightFront
upload_2018-7-27_18-15-35.png

AFAIK, there hasn't been another incident where a prop failure immediately followed a switch to Sport mode. Maybe the prop was damaged to begin with.
 
Joined
Jul 26, 2018
Messages
17
Likes
11
Age
42
#17
The .txt shows Sport starting at 118 secs. And, then the .DAT shows what appears to be a leftBack prop failure at 118.712 secs (about 0.7 secs after Sport mode was initiated). The leftBack speed increases in an attempt to produce more thrust from the failed prop. Concurrently, the rightFront speed decreases to match the lower thrust from the leftBack prop....
AFAIK there hasn't been another incident where a prop failure immediately followed a switch to Sport mode. Maybe the prop was damaged to begin with.
Thanks Bud. At least I know I didn't do anything terribly wrong to deserve this, and I know for future reference that I need to be meticulous about checking the prop hubs (that's where it failed). Maybe replacing them every 15-20 flights or so wouldn't be a bad idea anyway considering the cost of repairing the whole Mavic.

Bought this second hand. Anyone have any luck getting warranty/repair services if you're not the original owner/registrar? Otherwise I'll be posting surgery pics over the next few weeks...
 
Likes: borzoiboy

New Threads

Forum statistics

Threads
47,422
Messages
554,573
Members
70,166
Latest member
The Pepes