CEN22FA223

Two pilots were conducting a local flight to practice basic agricultural flight maneuvers. A witness observed the airplane enter a right turn at low altitude, during which the right wing dropped, and the airplane nosed down toward terrain and disappeared from his view. The airplane impacted terrain in a nose- and left-wing-low attitude in a field. The airplane sustained substantial damage to the fuselage, wings, and empennage. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The airplane damage was consistent with a near-vertical descent, indicative of an aerodynamic stall. It could not be determined which of the two pilots was flying the airplane at the time of the accident. The circumstances of the accident are consistent with the pilots’ failure to maintain sufficient airspeed while maneuvering, which resulted in an exceedance of the airplane’s critical angle of attack and an aerodynamic stall.

According to the FAA Airplane Flying Handbook (FAA-H-8083-3C): At the same gross weight, airplane configuration, CG location, power setting, and environmental conditions, a given airplane will consistently stalls at the same indicated airspeed provided the airplane is at +1G (i.e., steady state unaccelerated flight). However, the airplane can also stall at a higher indicated airspeed when the airplane is subject to an acceleration greater than +1G, such as when turning, pulling up, or other abrupt changes in flightpath. Stalls encountered any time the G-load exceeds +1G are called “accelerated maneuver stalls. The accelerated stall would most frequently occur inadvertently during improperly executed turns, stall and spin recoveries, pullouts from steep dives, or when overshooting a base to final turn. An accelerated stall is typically demonstrated during steep turns. On June 2, 2022, about 1745 central daylight time, an Aeronca 7AC, N1976E, sustained substantial damage when it was involved in an accident near Bowling Green, Missouri. The two pilots sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the airplane owner, the two pilots were planning to conduct a local flight to practice basic agricultural flight maneuvers. A witness, located in his residence about ½ mile from the accident site, reported that he saw the airplane at low altitude flying from the south to the north. The airplane then made a right turn to the east. During the turn, the right wing dropped, and the airplane nosed down toward the ground. The witness lost sight of the airplane behind some trees and located the airplane wreckage in a field adjacent to his residence. The witness stated that he had observed the airplane performing similar flight maneuvers over the nearby fields during the weeks before the accident. The front-seat pilot held a commercial pilot certificate with ratings for airplane single- and multi-engine land, airplane single-engine sea, and instrument airplane. The rear-seat pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. Postaccident examination of the accident site revealed that the airplane impacted the terrain in a nose- and left-wing-low attitude. The airplane sustained substantial damage to the fuselage, wings, and empennage. The left wing was separated from the fuselage by rescue personnel to facilitate recovery efforts. The vertical stabilizer and tail were twisted to the left, consistent with a counterclockwise stall/spin at the time of impact. (See Figure 1.) Figure 1. Airplane wreckage (left wing removed from fuselage by rescue personnel). Flight control continuity was established from the cockpit to all flight control surfaces. The engine remained partially attached to the firewall, and the two-bladed propeller remained attached to the engine crankshaft. The propeller blades displayed some forward twistingdeformation. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.