NTSB Identification: ERA11LA427
14 CFR Part 91: General Aviation
Accident occurred Friday, July 29, 2011 in Sarasota, FL
Probable Cause Approval Date: 12/11/2013
Aircraft: TL ULTRALIGHT SRO STING S3, registration: N2442
Injuries: 1 Fatal,1 Serious.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
After departure for the demonstration flight for the pilot-rated student, who was seated in the left seat, the airplane climbed to between 2,300 and 2,400 feet, and the pilot-in-command (PIC) then performed a stall. Subsequently, the flight entered a spin from which the PIC was unable to recover. The airplane descended uncontrollably into a large tree and then impacted the ground. The PIC reported that he could not recall how or why the airplane entered a spin. Although the airplane had been spin tested by the manufacturer, it was not approved for intentional spins. Examination of the wreckage, including the flight controls, and engine revealed no malfunctions or failures that would have precluded recovery from the spin.
Although the airplane was equipped with a ballistic recovery system parachute, it was found unarmed and, thus, did not deploy. The PIC reported that he chose to depart with the parachute system activation handle safety pin installed instead of removed, which was not in accordance with the procedures in the Pilot Operating Handbook. Further, the location of the activation handle behind the left seat on this airplane make and model would have rendered it difficult for the PIC, who was in the right seat, to access during the uncontrolled descent. The manufacturer moved the activation handle to the lower portion of the pilot’s instrument panel to allow for easier access.
The PIC reported that he performed weight and balance calculations before departure and based his calculations on the provided passenger weight (275 pounds); the airplane was at the top of the envelope but within weight and balance limitations. However, postmortem external examination indicated that the passenger actually weighed 340 pounds, which resulted in the airplane being 64 pounds above the maximum allowable ramp weight at engine start. Further, his actual weight was 90 pounds over the left seat’s design limitations (1.3 times the ultimate design load factor limit of each lapbelt attachment point), which caused the left seat outboard attachment structure to separate during the impact sequence.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The inability of the pilot-in-command (PIC) to recover from an inadvertent spin following a stall demonstration for reasons that could not be determined because aircraft and engine examinations did not reveal any anomalies that would have precluded recovery from the spin. Contributing to the severity of the accident were the PIC’s failure to remove the airframe parachute system safety pin before takeoff, the exceedance of the left-seat weight limitation, and the location of the parachute system activation handle behind the PIC’s seat, which prevented easy access during the uncontrolled descent. Full narrative available
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