DJI Drone Help Forum

Phantom 4 Pro crashed on first flight - please help!

Hi all. I’m a licensed commercial pilot. I bought a used P4P V.1. I checked it over, did all the calibrations and did a short test flight. After a minute and a half, it looked a bit unstable and while I was beginning to land it, it shot to the ground at a 45 degree angle and crashed!

Here is the flight record https://www.phantomhelp.com/logviewer/OOVALH3VJZOZK7NM5WCE

I have patched it up (cracked landing gear) and have done 7 flights since (in a different location) and there have been no problems. I am very nervous about using it now though, so I’d really appreciate any help in understanding what happened. The only thing I can spot in the record is a battery cell deviation for a few seconds at 45 secs in.

Thanks in advance.

I see a lot of things happening in that log. A lot of errors in the last column. And you lost all or almost all satellites at some point. And why does the altitude go negative? Did you fly down into something?

That wouldn’t cause a crash.

Your flight log shows you lost a prop mid-flight. Where were all of the props when you picked up the crashed drone?

From what I have learned about my 4 Pro 2 2.0 but mine is new, the device could be a problem, DJI only has one device thats 100% capatible, google phone 2, another thing calibration of the sensors thru the computer if the flight looks wobbly, since its used it could have been an underlying reason the thing was sold, I immediately purchased the DJI care, just in case, wonder how many hours it had on it and if it was ever registered to DJI, wonder if it could have crashed before and no exterior damage but something loose inside,

I’ve lots of experience with battery issues and P4As. P4As falling out of the sky, batteries melted in and not coming out. After a few drone replacements, I finally got one that held the battery without some movement. Battery connection failures are common with the P4 series. I now apply a very small amount of dielectric grease to the male charger terminals to spread it to the battery and bird. I also use a cheap handheld infrared thermometer after each flight to compare battery connection temp to battery body temp. With the grease, connection temp has been 10-14 deg. below battery body temp. In the past, before grease, It was the opposite. Higher connection temps indicate the connection as a heat source, which will cause problems or failure. The dielectric grease also makes for a really easy, low friction connection and reduces terminal wear when installing and removing the battery. I’ve been using it for over a year now and I recommend all P4 series owners do the same.