P4 Fresh Water Crash

[SpeedFreak!]

Hello!

I think this might be my first post since I have only used this site for reading and research over the last year, so I just want to make sure anyone reading this knows that I did a thorough search before starting this thread.

Earlier today my P4 freaked out as it was coming in for a landing and crashed into a bridge and into an ice cold fresh water river. Of course, I dove in after it so it was only in there for under 10-15 minutes and never went below a foot or two getting stuck on a rock where I was able to retrieve it. At some point, the battery ejected, but I do not know if that was before or after the bath.

I have not plugged it in to any power and will not until I can be sure it has thoroughly dried. I am seeking advice. If this were a cell phone, I would seal it in a bag of rice for five days. I did use a blow dryer on the cool setting attempting to blow out all the water.

There appears to be no visible damage, other than the broken props. What should I do before attempting to power it up for the first time? I am looking forward to any and all suggestions from this "pool" of experienced Drone pilots!

Thanks in advance for your help!

Jeremy
VicariousInfusion.TV

 

[msinger]

What should I do before attempting to power it up for the first time?

Make sure it is thoroughly dry and use a new battery.

 

[jbrown630]

Can you elaborate on "freaked out"?

 

[Kirby Johnson]

Hello!

I think this might be my first post since I have only used this site for reading and research over the last year, so I just want to make sure anyone reading this knows that I did a thorough search before starting this thread.

Earlier today my P4 freaked out as it was coming in for a landing and crashed into a bridge and into an ice cold fresh water river. Of course, I dove in after it so it was only in there for under 10-15 minutes and never went below a foot or two getting stuck on a rock where I was able to retrieve it. At some point, the battery ejected, but I do not know if that was before or after the bath.

I have not plugged it in to any power and will not until I can be sure it has thoroughly dried. I am seeking advice. If this were a cell phone, I would seal it in a bag of rice for five days. I did use a blow dryer on the cool setting attempting to blow out all the water.

There appears to be no visible damage, other than the broken props. What should I do before attempting to power it up for the first time? I am looking forward to any and all suggestions from this "pool" of experienced Drone pilots!

Thanks in advance for your help!

Jeremy
VicariousInfusion.TV

Let me guess................... Litchi?

 

[SpeedFreak!]

Can you elaborate on "freaked out"?

Well, the ONLY time my P4 has crashed... and this is the first serious crash... it was in the final moments of battery life. Sometimes when the battery gets below 20 percent, it flies more erratically and is more difficult to fly. It was on its return journey, and jerked left into the bridge girder before plunging into the river below. If it would've just continued flying straight, it would landed right in my hand.

 

[SpeedFreak!]

Let me guess................... Litchi?

No, actually, bone stock... I have not tried Litchi. Is it known for this type of event?

 

[SpeedFreak!]

Make sure it is thoroughly dry and use a new battery.

Thanks for your advice. I lost the battery that was in it, so I will certainly use a fresh one.

Should I seal the entire drone in a bag of rice? Do you (or anyone else) have any good suggestions for drying it thoroughly and KNOWING when it is thoroughly dry?

 

[msinger]

You could open the shell up to ensure there is no water trapped anywhere and let it air out.

 

[SpeedFreak!]

You could open the shell up to ensure there is no water trapped anywhere and let it air out.

Ok, sounds a little scary... won't that void the warranty or does that even matter now?

What are your thoughts on the hairdryer? Good, bad, pointless???

 

[msinger]

Crashing in water already voided your warranty.

 

[SpeedFreak!]

Crashing in water already voided your warranty.

Which was what I thought was more than likely; however, would that still be the case if the drone malfunctioned, causing the crash? Would the water crash still void the warranty in a case like that?

This is new territory for me. I always wondered how the warranty would work if something went wrong causing a crash that would then void the warranty that is supposed to protect against the very thing that caused the crash in the first place.

Sorry for all the questions. I appreciate all of your gracious advice.

 

[msinger]

Would the water crash still void the warranty in a case like that?

No.

 

[EPT160]

Thanks for your advice. I lost the battery that was in it, so I will certainly use a fresh one.

Should I seal the entire drone in a bag of rice? Do you (or anyone else) have any good suggestions for drying it thoroughly and KNOWING when it is thoroughly dry?

Made in the U.S.A. - Desiccant, Desiccant Packs in Stock - Uline

Best to go down to your local hardware shop and buy some bags/satchels of desiccant. Place them inside of the battery compartment and others inside of a large plastic bag. They will change colour when exhausted. Use fresh ones until no colour change.

Good luck

 

[Kirby Johnson]

No, actually, bone stock... I have not tried Litchi. Is it known for this type of event?

Do a search..............It is probably just me, but I bought it months ago but have never put anything in the air with it.

 

[SpeedFreak!]

Made in the U.S.A. - Desiccant, Desiccant Packs in Stock - Uline

Best to go down to your local hardware shop and buy some bags/satchels of desiccant. Place them inside of the battery compartment and others inside of a large plastic bag. They will change colour when exhausted. Use fresh ones until no colour change.

Good luck

Oh wow! Thanks!!! That sounds really great! I will get on that right away!

 

[SpeedFreak!]

Do a search..............It is probably just me, but I bought it months ago but have never put anything in the air with it.

I will do just that... you have peeked my curiosity. I did go to their website after your first comment. It looks really interesting but I can see where there could be problems, especially since it could conflict with the DJI software that is already there and quite excellent.

 

[Alex Baxter]

You can buy 'indicating' silica gel beads, get about a pound of it, seal the P4 in a bag with the beads. When the beads are indicating that they have expired (they change colour) nuke them in the microwave to remove the moisture, allow to cool, and re-use them, keep doing this until they don't change colour over a few days. Silica gel is a much more effective desiccant than rice.

Sent from my Nexus 9 using PhantomPilots mobile app

 

[Mikevipe]

The fact that your battery was missing upon recovery hints to me that the battery could have not been inserted securely and came loose mid flight causing the crash? I have read about this happening in the P3 threads.

A friend lost a P3S that hit a bird in mid air and it fell from 300-400 feet through some trees and finally on a cement parking lot, it was completely destroyed but the battery was still attached.

If the battery fell out you would have no power to the circuits upon impact with the water so the chances your drone would survive would IMO be higher once properly dried out.

 

[rene van der meer]

Luckily it was fresh water.
The battery probably popped out on impact. This is good fortune.
Many people got a drone back in the air after a water accident. An oven at moderate temperature would speed up drying time.
Was the SD card ok?

Sent from my SM-G925F using PhantomPilots mobile app

 

[adamu77]

Unfortunately the water gets almost everywhere inside the P4 - flight computer, 3-in-1 board, both esc's, power distribution board, gimbal, under most of the heat sinks, inside the gps rf shield, etc. A number of the components inside are made of magnesium and the water can corrode these parts very quickly too. Some of the circuitry has a conformal water-proof coating but it's not designed for this kind of incident. As mentioned if the battery fell out before or immediately on impact then it could have been a good thing and prevented damage to the circuitry (i.e. electrolytic corrosion and worse). You're best option is to return it to DJI under warranty (get them to analyse the DAT files on the flight data recorder- if a fault is found they should replace it) otherwise it's a big job to take it apart and dry and clean it. If the water was very pure, you -might- be able to get away with thoroughly drying everything (it will still require disassembly), but better off to clean everything preferably with the help of an ultrasonic cleaner/isopropanol etc.