14 CFR Part 91: General Aviation
Accident occurred Sunday, April 06, 2014 in Summerfield, FL
Probable Cause Approval Date: 04/14/2016
Aircraft: MONROE DENNIS RV-7, registration: N57DC
Injuries: 2 Fatal.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The private pilot, who was also the owner/builder of the experimental amateur-built airplane, was assisting with the production of a film throughout the afternoon, and the purpose of the accident flight was to record video footage from the air. After departing from the grass runway, the airplane entered a circular left orbit around a tightly clustered group of actors on the ground at an altitude just above the tops of nearby trees. The airplane had completed three circuits, and during the fourth, it appeared to witnesses to be flying slower than it had during the previous circuits.Analysis of video from onboard the airplane, video taken of the airplane from the ground, and witness statements showed that the airplane banked steeply left and began descending toward the ground at a relatively steep angle, consistent with inadvertent entry into an aerodynamic stall. As the airplane descended, the engine power rapidly increased, and the airplane began banking back toward a wingslevel attitude as its pitch attitude increased; these actions are consistent with the pilot recognizing and attempting to recover from the stall. The airplane subsequently impacted the ground in a nearly level and slightly nose-down pitch attitude. Signatures observed on the wreckage were indicative of high engine power at impact, and no evidence of any preimpact mechanical malfunctions or failures were observed on the airframe and engine.Examination of damage to the airplane’s horizontal stabilizer revealed that it failed from overstress due to ground impact. The majority of the spar cracks and fracture surfaces exhibited features consistent with overstress failure. The other damage features present on the spar section were consistent with ground impact. Although some fatigue cracks were present in the spar sections, the fatigue crack sizes were small, and crack orientations were inconsistent with the stress direction of the overstress portions of the fracture. These cracks were unlikely to have resulted in an in-flight failure of the horizontal stabilizer. Even if the spar had fractured before impact, the remainder of the part was still riveted to adjacent structural components within the stabilizer.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's failure to maintain airplane control while maneuvering at a low airspeed, which resulted in an aerodynamic stall, and his decision to maneuver at an altitude that did not allow an adequate margin to recover from a stall.