What happened
On July 10, 2024, at approximately 12:10 mountain daylight time, an Air Tractor AT-802A, registration N10122, crashed near Helena, Montana. The aircraft was being operated by Aero Spray Inc as a single engine air tanker (SEAT) in support of aerial firefighting efforts for the Horse Gulch Fire.
The flight departed Coeur d’Alene Airport – Pappy Boyington Field (COE) in Idaho approximately 1 hour and 44 minutes before the accident. The aircraft was part of a four-plane formation flying to Hauser Lake to perform water scooping operations. During its first scoop sequence, witnesses on the lake and pilots in the two aircraft following the accident plane observed it make a left turn toward the southwest. The aircraft then struck a vertical rockface on the southern shoreline of the lake, fell into the water, and sank.
Flight tracking data from the SpiderTracks system indicated that after departing COE, the aircraft climbed to approximately 9,400 feet MSL. After a descent began at 11:46, the group of four aircraft flew over Hauser Lake and completed several turns. The N10122 descended to the lake surface on a track of approximately 279° magnetic, traveling about 4,233 feet over the water. The aircraft then turned left to a heading of 269° and traveled an additional 1,447 feet before the tracking data ended near the accident site.
The investigation
Examination of the accident site showed the aircraft remained mostly intact while submerged on a sloped lakebed near the southern rockface. The water depth at the site ranged from 10 feet at the nose to 30 feet at the tail. The aircraft rested in a tail-low attitude on a heading of approximately 225° magnetic. The propeller assembly had separated from the aircraft and was located at the base of the cliff. Both floats had separated from the airframe and were found floating on the lake surface. All major structural components were located at the site. The wreckage was recovered for further examination.
1 fatal injury was reported.