Amateur-built DHC-6-300 accident near Whitmore, Arizona, August 9, 2025

The NTSB's narrative preliminary · quoted from the NTSB record

On August 9, 2025, about 1240 Pacific daylight time, a De Havilland DHC-6-300, N189GC, was substantially damaged when it was involved in an accident near Whitmore, Arizona. Six passengers sustained minor injuries, and the captain, first officer and remaining eight passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 135 on-demand air taxi flight. The flight departed from Boulder City Municipal Airport (BVU), Boulder City, Nevada, to transport the passengers to Grand Canyon Bar Ten Airstrip (1Z1), Whitmore, Arizona, where they were scheduled to begin a river tour. The airplane was the second in a group of four, that were due to arrive at about the same general time. The first airplane to depart was a Cessna 208 (Caravan), with the remaining three airplanes all similarly equipped DHC-6-300’s. 1Z1 is a remote airstrip, located at an elevation of 4,100 ft mean sea level (msl), within a 2 ½ mile wide valley, surrounded by steep rising terrain. It had a single, 4,600 ft long by 40 ft wide north/south oriented runway, 4,000 ft of which was composed of a 33 ft-wide asphalt chip seal surface. The airstrip did not have a weather reporting station, and the crew checked area weather before departure, which indicated gusting winds out of the west. The pre-flight preparations, boarding, and enroute cruise segment of the flight were uneventful, with the first officer flying the airplane. During the final stages of cruise flight, the crew checked the weather at Grand Canyon West airport (1G4) (38 miles southwest of 1Z1), which indicated wind from 270° at 13 knots, gusting to 22 knots. The crew consulted with the Caravan pilot, who had just departed the area after dropping off passengers, and he stated the wind conditions were strong, variable, and gusting, but favoring runway 16. The crew discussed the arrival and landing procedures and decided that based on prevailing wind conditions and terrain clearance should they need to perform a go-around, runway 16 was the most prudent choice. They then configured the airplane for descent, with the captain assuming the role of pilot flying. The captain reported that the final approach was stable, on speed, on centerline, and although gusting winds were causing changes in airspeed, they were not enough to require large changes in engine power. Due to the westerly winds, the captain was maintaining a crab angle while the airplane was on final, and as they got closer to the runway, she could see the windsocks were “pegged” and indicating winds directly out of the west. The captain reported that shortly after touchdown, which was between 500 and 1,000 ft beyond the threshold, she was able to maintain directional control with right aileron and left rudder control input, and the airplane tracked down the runway centerline while she retarded the engine power levers to the zero-thrust position. As they approached the runway midpoint, the captain described a sensation that felt as if the airplane was being “pushed”. She maintained full left rudder input and began to release the right aileron control pressure. The airplane then departed the runway surface to the right and entered the dirt edge of the paved surface. She was still able to maintain the runway heading but could not direct the airplane back onto the paved surface. The gravel area became bumpier, and as they approached a ditch, the captain applied aft control yoke to raise the nose, and prevent the nose gear from digging in. Ground disruptions and runway markings were consistent with the airplane swerving left as the terrain rose. The left wingtip then struck the runway, and the airplane then began a sharp right turn, about the time the captain reported applying brakes and retarding the engine controls further. The airplane then struck a deep ditch, just beyond, and to the right of the departure end of the runway, where it came to rest upright. The crew secured the airplane while evacuating the passengers. The airplane sustained substantial damage to the left wing, and entire forward fuselage structure during the accident sequence.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.