Eagle vs. EGLE: Bald Eagle Annihilates State’s $950 Drone, Sends it Crashing to Bottom of Lake

   08.14.20

Nature and technology clashed last month when a bald eagle attacked a $950 drone that was mapping shoreline erosion along Lake Michigan.

Nature inevitably won the battle, and the drone now sits at the bottom of the lake.

The drone was being operated by Hunter King, a Michigan Department of Environment, Great Lakes, and Energy (EGLE) pilot. The “brazen” airborne attack on the drone took place near Escanaba in Michigan’s Upper Peninsula on July 21 when King was assigned to collect data for use in the agency’s efforts to document and help communities cope with high water levels.

King had completed about seven minutes of the mapping flight — his fourth of the day in the area — when satellite reception got spotty. He pressed the “Go Home” recall button. The drone dutifully turned, reacquiring a strong satellite feed.

King was watching his video screen as the drone beelined for home, but suddenly it began twirling furiously. “It was like a really bad rollercoaster ride,” said King. When he looked up, the drone was gone, and an eagle was flying away. A nearby couple, whose pastimes include watching the local eagles attack seagulls and other birds, later confirmed they saw the eagle strike something but were surprised to learn it was a drone. Both King and the couple said the eagle appeared uninjured as it flew from the scene of the crime.

The couple joined King in a search, but hours of scouring the shoreline were fruitless. Several days later, armed with telemetric data from the flight that pinpointed exactly where the drone hit the lake — 150 feet offshore in four feet of water – EGLE Unmanned Aircraft Systems coordinator Arthur Ostaszewski brought a kayak and snorkeling gear to the search. With near-zero visibility in water darkened by tannin, Ostaszewski scrapped the snorkel and instead walked a grid pattern shuffling his feet for two hours in soft muck (“like I was playing Battleship and wanted to cover the entire board”). He too was luckless, abandoned the search when lightning began to accompany a cold drizzle.

The drone, a $950 Phantom 4 Pro Advanced, is no longer in production, and will be replaced with a similar model.

Data from the flight records detailed the drone’s final moments:

  • The eagle strike occurred 7:39.7 into the flight roughly four-tenths of a mile from King and 162 feet above the water
  • Its speed instantly dropped from 22 mph to 10. Within a half-second the flight record shows the beginning of downward spiral along with “excessive spinning” warnings
  • In the next 3.5 seconds the drone sent 27 warning notifications including one indicating a propeller had been torn off
  • Gaining momentum as it fell, its last communication came at 34 feet above the water, falling at 30 feet per second, or 20.4 mph.

The attack could have been a territorial squabble with the electronic foe, or just a hungry eagle. Or perhaps it took issue with its name being spelled incorrectly, the department suggested tongue-in-cheek.

EGLE’s drone team is now considering steps to reduce the possibility of a repeat attack, including possibly using “skins” or other designs on the aircraft to make them look less like seagulls. I’m certainly no expert on eagles, but something tells me the bird of prey will sniff out the drones regardless of a protective “skin,” so hopefully they have more drones on hand. Maybe they should look into using HECS technology, which is supposed to work particularly well with birds. Just my two cents!

Eagle populations have rebounded in Michigan. A 2019 U.S. Fish and Wildlife Service survey showed 849 active nesting sites In Michigan, up from a low point of 76 nesting sites in the 1970’s.

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