High Tension Power Lines 1 : Mavic Pro Platinum 0

After thousands of miles of Litchi waypoint missions flown without incident, the law of probabilities finally caught up with me and the result was a Mavic Pro Platinum engaging some high-tension electric cables in a life-and-death duel, with predictable results.

I had been testing the newly released extended-range battery for the Mavic 1 Pro and Pro Platinum, and the drone was 3 miles from home after traversing the skies above a huge palm tree plantation and a couple of swamps when it sent me an RTH alert.

Other users of this battery had recommended disabling smart RTH prior to takeoff, yet I was reluctant to cut that safety tether, and so foolishly opted to cancel RTH on the fly, banking on the premise that the drone would then complete the 12-mile round trip waypoint sequence without incident after my initial RTH cancellation.

Unexpectedly signal loss occurred at the precise moment when I canceled RTH, and I now surmise that the 240-foot RTH altitude I’d pre-set was either not sufficient to clear the high-tension cables or was inexplicably ignored by the drone, such that it went into a dive at the worst possible moment. and flew backward into the cables, at which point gravity exerted its influence without mercy.

Hopped in the Jeep and sped to the crime scene as indicated on my Litchi map screen, and after a few minutes of stumbling about in a corn farm, located the Mavic Pro Platinum where it had landed in the soft grass. The massive after-market battery had been ejected on impact and showed clear signs of abrasion where it was scuffed by the power line, while the battery housing has a minor dent in it. Tested the battery and it does power up the drone normally.

After my official mourning period has been observed, I will conduct a test of this drone, whose rear panel now sports a significant structural crack which may or may not mean the drone has breathed its last. Amazingly the camera of the drone appears intact. The fact that the drone was flying backward at the moment of impact is the reason why that camera was spared any visible damage.

I’ll take a few post-mortem photographs later today and add them to this thread. If I were to cite a lesson learned from this debacle, it would be that anyone who has installed a larger-than-stock battery in their Mavic 1 Pro or Mavic Pro Platinum should just go ahead and cancel smart RTH before takeoff IF they are intent on exploring the new range envelope made possible by that larger battery. Better risk landing with 15% battery than risk the drone adopting unpredictable RTH altitudes.

I conducted a flight test and to my utter amazement both the Mavic Pro Platinum and the new extra capacity battery I bought for it worked perfectly, flying a Litchi waypoint mission without a glitch. There is, however, one anomaly to report. The camera no longer remains in the usual 20 degrees downward tilt angle that I prefer for my flights unless I hold the thumb wheel in place constantly.

The instant I take my finger off the camera tilt wheel on my RC controller, the camera tilts upward to zero degrees. and remains there unless I hold the spring-loaded camera tilt wheel in place to keep the camera pointed down. I will run a camera calibration to see if I can cure this solitary flaw that emerged after that horrific crash, and will report my findings here just in case anyone else encounters a camera tilt issue either in the wake of a crash or out of the blue.

All told I am impressed at the resilience of this Mavic Pro Platinum. There is a horrendous crack in the rear panel of the drone, and right after the crash, I did note that one of the rear motors didn’t spin as freely as it should, though it did resume normalcy minutes later.


The cause of this crash turned out to be as bizarre as it was avoidable. By unfortunate coincidence, the signal link between my RC controller and the Mavic Platinum Pro glitched at the precise moment when I deselected smart (low-battery) RTH while the drone was cruising at 28mph well over 3 miles out and still en route to the turnaround point where it was to fly two concentric circles over a ground structure of interest, before heading back home.

Unsure of whether my cancel RTH command was transmitted due to the ill-timed RC signal glitch, I decided to re-establish RC contact with the drone by scurrying up the ladder of a nearby 60-foot water-tank tower, with my RC controller foolishly left switched on and connected to my iPad that was nestled on the floor of the shoulder-bag slung around my neck, as I did my best primate impression scaling the tall tower. This hurried and somewhat risky expedient had proved effective as a last-ditch gambit several times in the past without anything untoward happening, but things were to wind up going depressingly awry this time around.

As fate would have it, and Lady Luck nowhere in sight, the RC controller did re-establish its signal link with the errant drone at the worst possible moment during my clambering ascent up that water tower ladder, which was regrettably before I reached my usual vantage point and while I still had both hands fully occupied climbing the ladder. The debacle that unfolded next became painfully evident after I finally retrieved the crashed drone and played back the footage documenting its final moments before it flew backward into power lines.

It just so happened that the RC controller which I had hurriedly stuffed in a side pocket of my shoulder bag for that ladder climb, wound up with both left and right joysticks in the fully aft position, meaning the throttle was cut to flight idle, and the Mavic Pro Platinum was in a fully nose-up position, which launched it into backward flight. Those two fully-aft joystick positions were received by the drone for just a few seconds while the RC controller was still crammed inside my shoulder bag as I completed my ladder ascent, but that brief moment was all it took for the drone, whose collision sensors I had thoughtfully de-selected to maximize airspeed, to unceremoniously embark on a rapid decent while flying backward, directly towards the looming high tension power lines as the camera rolled.

By the time I completed my ladder ascent moments later and retrieved by RC controller from the shoulder bag, the crash had already occurred and the drone was lying in deep grass directly beneath the high-tension power lines 3 miles away as the drone flew but a 7-mile drive away, with its strobe luckily flashing and still affixed to its rear-panel attachment location that was scant millimeters below the power line’s point of impact when the drone backed into it. Litchi’s final position map put me within 50 yards of the drone’s crash site after I arrived in my Jeep to hunt for it in an overgrown cornfield, and that flashing Firehouse strobe light enabled a fellow searcher to find the remarkably undamaged Mavic Pro Platinum nestled in tall grass where it evidently made a soft landing, against all rational odds.

The most significant lesson I derived from this unfortunate adventure, is that for anyone who resides as I do in the Third World boondocks beyond the jurisdiction of the FAA and CAA, and who has purchased one of those extra capacity batteries that can allow a Mavic 1 Pro or Mavic Pro Platinum to cruise aloft for 35 minutes as opposed to 23 minutes of a stock M1P battery, it is VITAL that BOTH obstacle avoidance AND low-battery RTH should be disabled BEFORE takeoff, so that intermittent RC signal connectivity does not lead to unexpected outcomes of the sort I described here. Also, it is best to power OFF the RC controller shortly after takeoff and to leave the RC controller off until 5 minutes before its expected time of arrival, which is usually a nominal 5 minutes EARLIER than would be deduced from Litchi’s on-screen flight duration estimate.

Provided that winds are calm, programming fully autonomous beyond-RC signal Litchi waypoint missions only requires that the estimated flight time shown on the Litchi Mission Hub flight planning map is LESS THAN 35 minutes when the drone is fitted with an extra range battery. Since autonomous Litchi waypoint flights generally arrive at the home launch point 5 minutes BEFORE the estimated flight duration shown on the Litchi Mission Hub screen elapses, a Litchi waypoint flight estimated to last 35 minutes will complete its programmed sequence of waypoints and arrive at the launch point precisely 30 minutes after the flight was launched, assuming of course that winds aloft are moderate to calm for the duration of that waypoint mission.

Typo corrected. Drone model name error retyped.

As an uplifting footnote to my crash report, I sent the Mavic Po Platinum on another waypoint mission following the same flight path as the last ill-fated mission that ended in a crash, but at 246 feet altitude all the way. To my utter amazement, the ONLY post-crash anomaly that I previously observed, namely that the camera would not stay tilted down to my preferred -20-degree position, mysteriously resolved itself.

Not only that, but the annoying video footage issue that I observed in the past with this drone, in which the footage filmed was badly out of focus, ALSO righted itself completely after that crash, such that this drone now flies and films absolutely flawlessly, DESPITE a massive rear fuselage crack right where the delicate GPS unit is housed. This Mavic Pro Platinum is a rampaging beast that simply refuses to die, despite losing a skirmish with a high-tension, high-voltage electricity cable.

I am absolutely sure that this Mavic Pro Platinum, fitted with the after-market longer-range hunch-back battery I snagged on Ali Express, WILL prove capable of covering a whopping 14 miles round trip flying fully autonomous Litchi waypoint missions while I relax indoors with the controller switched off. When I complete my first record-shattering long-distance waypoint flight, I will probably open a new discussion thread just to boast about that feat. Over and out for now fellow brethren of the Mavic1 Pro.