3 fatalities

2017-03-14: Pilatus PC-12 (08-0724) — United States Air Force - USAF (since 1947) — Cannon AFB (Clovis), United States of America

Cannon AFB (Clovis), United States of AmericaLanding (descent or approach)

On March 14, 2017, a Pilatus PC-12 (registration 08-0724) operated by United States Air Force - USAF (since 1947) was involved in an aviation accident near Cannon AFB (Clovis), United States of America during landing or approach. 3 people were killed. Investigators recorded the probable cause as: By a preponderance of the evidence, the Accident Investigation Board concluded the aircrew lost control of the aircraft when it entered a stall at low altitude during a turn back Emergency Landing Pattern procedure. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 16 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781191962Data APIEditorial standards

On March 14, 2017, a U-28A (tail 0724) crashed near Clovis Municipal Airport during a practice turnback emergency landing, killing all three crewmembers.

Incident Overview

On March 14, 2017, at 1835 local time, a U-28A aircraft (tail number 0724) crashed approximately one-quarter mile south of Clovis Municipal Airport in New Mexico. The aircraft, operated by the 318th Special Operations Squadron, 27th Special Operations Wing, Cannon Air Force Base, was destroyed upon impact. All three crewmembers—Captain Andrew Becker (pilot), First Lieutenant Frederick Dellecker (copilot), and Captain Kenneth Dalga (combat systems officer)—died.

Flight History

The aircraft departed Cannon AFB at 1512 local for a mission involving tactical training over Lubbock, Texas, followed by pilot proficiency training at Clovis Municipal. The crew entered Lubbock airspace at 1545, completed tactical training, and departed for Clovis at 1735. At 1806, the crew entered the traffic pattern at Clovis Municipal and conducted multiple approaches and landings before executing the mishap maneuver—a practice turnback emergency landing pattern.

Mishap Maneuver

During the practice turnback pattern, the aircraft was configured with 0 degrees of flaps. This configuration led to increased nose-down attitudes and higher descent rates necessary to maintain a safe angle of attack compared to a 15-degree flap configuration. Additionally, stall speeds with 0 degrees flaps are 15 to 25 knots higher than with 15 degrees flaps, depending on bank angle. The crew was late in achieving the required bank angle to align with the runway centerline, resulting in an overshoot condition.

Loss of Control

To correct the excessive nose-down attitude, descent rate, and shallow bank, the crew pulled back on the yoke and increased bank angle. The resulting g-load from the pull, combined with the increased bank, slowed the aircraft below the 0-degree flap stall speed, causing it to depart controlled flight. Subsequent power increase and flight control inputs could not recover the aircraft from the stall within the remaining altitude. At no point during the maneuver did the aircraft's performance indicate an intent to abort.

Final Moments

The aircraft impacted the ground with a 13-degree nose-high, 7-degree left-wing low attitude. It was destroyed on impact, and all three occupants were killed. The Accident Investigation Board found no indications of mechanical malfunction.

Probable cause

By a preponderance of the evidence, the Accident Investigation Board concluded the aircrew lost control of the aircraft when it entered a stall at low altitude during a turn back Emergency Landing Pattern procedure. The board also surmised the crew delayed actions necessary to prevent the aircraft from entering the stall envelope and failed to accurately assess increasing risk throughout execution of the practice turn back Emergency Landing Pattern, thereby substantially contributing to the mishap.