Airplane Began A 4,000-Fpm Descent That Lasted About 12 Seconds

Location: Safford, AZ Accident Number: WPR20LA176
Date & Time: 06/09/2020, 0845 MST Registration: N173CW
Aircraft: Vans WILSON RV4 Injuries: 1 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal

On June 9, 2020, about 0845 mountain standard time, an experimental amateur-built Wilson (Vans Aircraft) RV4, N173CW, was substantially damaged when it was involved in an accident near Safford Regional Airport (SAD), Safford, Arizona. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

Preliminary ADS-B data revealed the airplane departing from runway 11R at Tucson International Airport (TUS) about 0810, and initiating a climbing left turn to the northeast. The airplane continued on the same track, reaching an altitude of about 9,800 ft mean sea level (msl), about 7 minutes later. For the next 25 minutes, the airplane maintained the same general altitude and heading while traversing the mountain passes northeast of Tucson, and maintaining terrain clearance of between 4,000 and 7,000 ft above ground level.

About 0836, 28 miles southwest of SAD, the airplane began to descend at a rate of about 500 ft per minute (fpm). Seven minutes later, the airplane changed track to the north, toward SAD, with an accompanying reduction in groundspeed from 165 to 115 knots and an increase in descent rate to about 800 fpm. After arriving about 1 mile south of the approach end of runway 30, at an altitude of 4,200 ft, the airplane turned 10° to the left, and began a 4,000-fpm descent that lasted about 12 seconds.

The first identified point of impact consisted of a 25-ft long ground disruption located at an elevation of 3,090 ft, about 500 ft north of the last ADS-B target, and 1/2 mile southwest of the runway 30 threshold. The disruption was on a south-facing bluff, and projected uphill on a north heading toward the main wreckage. The ensuing 300-ft long debris field contained fragments of wing tip, main landing gear, the propeller and exhaust pipe assembly, and the left aileron.

The main wreckage came to rest 40 ft above the first point of impact, and 40 ft below the runway elevation.

FMI: www.ntsb.gov