STEELE RALPH BRUCE STEEN SKYBOLT near Windsor, NC — 2013-05-11

Probable cause

The pilot's decision to initiate an aerobatic maneuver with insufficient altitude to recover before ground impact.

NTSB narrative

The pilot of the experimental homebuilt aerobatic biplane reported that he decided to do some "maneuvers." After takeoff, he did one flyby in an easterly direction along the runway and then did a second one. At the end of the second flyby, he pulled up to between 300 and 500 feet and performed a "wingover" maneuver. According to the pilot, at the bottom of the wingover, he noticed that the engine did not respond when he advanced the throttle and that the rpm was decreasing through 2,000. The airplane then descended into a field and impacted terrain. According to federal regulations, no person may operate an aircraft in aerobatic flight below an altitude of 1,500 feet above the surface. Examination of the accident site revealed two 40-foot-long impressions that matched the geometry of the main landing gear and ended at the point where the airplane made initial ground contact with its left wing. The airplane then continued traveling forward for another 200 feet after initial ground contact before dissipating its energy and coming to rest. The impact evidence indicates that the airplane was well above its stall speed at impact. Further, examination of the airframe and engine revealed no evidence of any preimpact malfunctions or failures that would have precluded normal operation, and the crush and compression damage to the lower left wing was consistent with the airplane incurring a high-G impact. Additionally, the G-meter indicated 5 1/2 Gs positive and 3 1/2 Gs negative.

Analysis

Primary failure mode

Loss of control

First missed decision gate

Pilot could have avoided aerobatic maneuvers at low altitude.

NTSB coding

• Abrupt maneuver · Maneuvering-aerobatics
• Decision Making / Judgment

Evidence available

• Photos
• 18 docket documents

Docket documents18

• Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1form
• Pilot Interviewinterview
• Pilot's Statementinterview
• Drawing of Accident Site as Provided by FAAother
• Excerpts from NAVAIR 00-80T-112 (Wingover)other
• Steen Skybolt Three View Drawing and Specificationsother
• Photo 10: G-Meter - Courtesy of FAAphotos
• Photo 1: Begining of Impressions in Wheat Field Leading to Main Wreckage - Courtesy of FAAphotos
• Photo 2: Close Up of Impressions - Courtesy of FAAphotos
• Photo 3: Area of Left Lower Wing Ground Contact - Courtesy of FAAphotos
• Photo 4: Main Wreckage - Courtesy of FAAphotos
• Photo 5: Left Upper and Lower Wings - Courtesy of FAAphotos
• Photo 6: Close Up of Left Lower Wing - Courtesy of FAAphotos
• Photo 7: Image of Right Upper and Lower Wings - Courtesy of FAAphotos
• Photo 8: Close Up of Right Lower Wing - Courtesy of FAAphotos
• Photo 9: Front View of Main Wreckage - Courtesy of FAAphotos
• Satellite Image of Accident Areaphotos
• Weather Reports and Records (KEDE METARS)report