ESCANABA — An Upper Peninsula bald eagle launched an airborne attack on a drone operated by a Michigan Department of Environment, Great Lakes, and Energy (EGLE) pilot last month, tearing off a propeller and sending the aircraft to the bottom of Lake Michigan.

The brazen eagle vs. EGLE onslaught took place near Escanaba on July 21 when EGLE environmental quality analyst and drone pilot Hunter King was mapping shoreline erosion 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.