Accident Overview
On July 10, 2024, at about 1210 mountain daylight time, an Air Tractor AT-802A, registration N10122, was substantially damaged when it crashed into Hauser Lake near Helena, Montana. The pilot sustained fatal injuries. The aircraft was operated as a public use aircraft for aerial firefighting in support of the Horse Gulch Fire.
Flight Path
The operator dispatched four single-engine air tankers (SEATs) from Coeur d'Alene Airport – Pappy Boyington Field (COE) in Coeur d'Alene, Idaho. The flight departed approximately 1 hour 44 minutes before the accident and flew directly to Hauser Lake to begin scooping water. The accident aircraft held the No. 2 position. During its first scoop sequence, witnesses on the lake and pilots of the two SEATs following behind observed the airplane execute a left turn to the southwest. Shortly after, it impacted a vertical rockface on the southern shoreline of the lake, fell into the water, and sank.
Data from the onboard SpiderTracks flight tracking system showed that after departing COE, the airplane turned to a southeasterly heading and climbed to about 9,400 ft mean sea level (msl). It continued at altitudes between 9,275 ft and 9,575 ft msl until beginning a descent at 1146. The group of four aircraft overflew Hauser Lake, conducted several turns, and then made a descending right turn from the east side. The accident airplane descended to the lake surface on a track of about 279° magnetic and traveled about 4,233 ft over the water. It then turned left to a heading of 269° and traveled about 1,447 ft until the data ended near the accident site.
Wreckage Examination
Examination of the accident site revealed that the airplane remained largely intact and was submerged on the sloped lakebed adjacent to a vertical rockface on the lake's southern edge. It came to rest on a heading of about 225° magnetic in a tail-low attitude, with water depth ranging from 10 ft at the nose to 30 ft at the tail. The propeller assembly was separated and found at the base of the cliff underwater. Both floats were separated from the airframe and remained floating on the surface. All major structural components were located at the accident site. The wreckage was subsequently recovered and transported to a secure location for further examination.