Drone Autopsy

Ever seen the innards of a drone? Avert your eyes if you're queasy.

Alert Gazette readers will remember this traumatic incident, and the roller coaster of emotions it fostered. It ended in a half-hearted optimistic fashion, as I awaited the results of my feeble attempts to resurrect my waterlogged drone, fingers crossed but frankly skeptical of the chances for success.

And, of course, my skepticism was well-founded. Despite 72 hours of basking in the presence of the finest rice, followed by a stint in the company of a package of dessicant of the highest quality (although the fine print clearly warned that it was not for drying items, just for removing humidity from closed containers…but desperation cares nothing for fine print), the drone refused to start up.

So, I did what I always do when confronted with a dead piece of equipment: I disassembled it to determine for myself the cause of death.

I wasn’t sure whether the correct term for this procedure is post-mortem or autopsy, so I googled them. They mean the same thing, although “autopsy” is derived from the Greek autopsia, meaning to see for oneself. That’s pretty much the reason for my exploration of the drone’s innards, so I’m going with that, even if post-mortem sounds more grownup.

The drone is held together by scores of the tiniest screws I’ve ever seen (or attempted to see). I did find a 000-sized screwdriver in my kit, and managed to force out all the screws that mattered. The first cover I removed revealed a circuit board that showed definited signs of oxidation, but didn’t really look all THAT bad (to my ill-informed eyes, at least). Surely I could use a small wire brush to clean up those contacts.

Photo: DJI Air 2s drone with bottom cover removed, showing damaged circuit board
Yeah, it’s not good…but is it REALLY bad?

However, I removed a few more screws and disconnected some leads, and the underlying circuit board clearly revealed the extent of the damage…damage from which there was no return, absent divine intervention or access to a time machine.

Photo: DJI Air 2s drone with bottom cover removed, showing damaged circuit board
OK, “really bad” is actually an understatement.

Once I reconciled myself to the fact that this was an unreparable situation, I focused on understanding exactly why it happened. I mean, I know that 24 hours submerged in fresh water can’t be good for electronics, but even so, this damage seemed a little extreme.

My theory was this: because the drone crashed with an almost completely charged battery, electrical current continued to trickle through the circuitry, hastening the corrosion process. But wait…isn’t fresh water supposed to be less reactive? I needed a more expert opinion. I needed — AI.

I’ve been trying out Meta’s new AI chatbot, creatively entitled “Meta AI,” and I’ve been pretty impressed with its performance. So I posed the question of how my drone came to such an corroded state in fresh water. Here’s its response:

A thrilling tale of a drone’s adventure!*

Corrosion occurred due to the exposure of your drone’s circuit boards to water and electrical current. Here’s a breakdown of the factors that contributed to corrosion:

Water: Freshwater creek water contains minerals like calcium, magnesium, and potassium, which can conduct electricity and facilitate corrosion.

Electrical current: With the battery still charged, electrical current continued to flow through the circuit boards, causing an electrochemical reaction that accelerated corrosion.

Oxidation: When the circuit boards came into contact with water, the metal components (like copper, aluminum, or tin) reacted with oxygen, leading to the formation of oxides and corrosion.

Conductive water: The water in the creek acted as an electrolyte, allowing ions to move between the metal components and facilitating the corrosion process.

*Yes, it actually prefaced its answer like this.

So my basic theory was correct, but I underestimated the “purity” of our creek water. (It’s not really that pure; I certainly wouldn’t drink from it.)

Having satisfied my curiosity and put to rest any faint hopes of repair, I completed my disassembly by removing the gimbal-mounted camera. At the risk of sounding overly anthropomorphic, holding it in the palm of my hand felt like holding someone’s detached eyeball. *cue Rocket Raccoon*

Its dead stare was pitiful and heartbreaking.

I had quickly moved through the five stages of grief, and landed on the less well-known sixth: getting a replacement for the lost loved one. DJI has replaced the Air 2s with the Air 3, an aircraft with enhanced photographic capabilities, but also with an enhanced price. As I already had a signficant investment in batteries and accessories, I was able to procure a replacement Air 2s at a pretty reasonable price, and it’s now resting in my office, ready for duty.

I should also mention that I purchased a 2-year extended service agreement that covers not one, but two unplanned water landings.

Postscript: Autopsy, She Wrote

I mentioned above that I googled the distinction between autopsy and post-mortem. As Google is prone to do, it helpfully provided a list of questions ostensibly related to my query, along with links to the answers to those questions. One of the “related” questions was more than a little macabre; here’s a screenshot:

Google's answer to the query, Can you do an autopsy on a dead person?

I assume the questions that Google chooses to accompany a given query are based on other actual searches, and while the answer was clinical and proper, the question itself made me think that the IP address of the searcher should be on file with the Violent Crime’s section of the FBI’s Criminal Investigation Division**.

The answer I would have provided, were I Google, is that an autopsy on anything other than a dead body is called vivisection, and is the likely precursor to murder, not to mention the source material for a TV movie.

**The alternative explanation for the reason for the question would be curiosity about who, exactly, is qualified to perform an autopsy, as in, “can I, a curious-but-untrained human, do an autopsy on a dead body that I happen to run across?” But, here again, let’s call the FBI, shall we? 🤣