Pilot Debrief

TL ULTRALIGHT SRO STING S3 near Sarasota, FL — 2011-07-29

Final reportERA11LA427
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Date
2011-07-29
Location
Sarasota, FL, USA
Aircraft
TL ULTRALIGHT SRO STING S3
Registration
N2442
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Maneuvering

Probable cause

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.

Contributing factors

Contributing to the accident were the pilot-in-command’s failure to remove the airframe parachute system safety pin before initiation of the flight, and the location of the airframe parachute system activation handle behind the co-pilot’s seat which prevented easy access during the uncontrolled descent.

NTSB narrative

The purpose of the flight was a demonstration flight for the pilot-rated student who had not flown in 16 years. The pilot-in-command (PIC) seated in the right seat stated that he performed weight and balance calculations before departure and based his calculations on the provided passenger weight (275 pounds); reporting the airplane was at the top of the envelope but within weight and balance. The PIC elected to depart with the aircraft parachute system activation handle safety pin installed because as he later stated he had not been trained on its use, and because he did not intend on flying above 3,000 feet. After departure the flight climbed to between 2,300 and 2,400 feet, where a stall was performed and the flight entered a spin. The airplane descended uncontrolled into a large tree then impacted the ground coming to rest upright. The left seat occupant advised the 911 dispatcher while summoning assistance that the PIC was unable to recover from the spin. Both occupants were airlifted to a hospital where the left seat occupant died while hospitalized 3 days later. The PIC reported the next day while hospitalized he could not recall how or why the airplane entered a spin. Postaccident inspection of the airplane following recovery revealed no evidence of preimpact failure or malfunction of the aileron, elevator, or rudder flight control systems. The flaps were found fully extended, and there was no preimpact failure or malfunction of the primary or secondary flight controls, or of the structure necessary to sustain flight. Inspection of the engine-driven fuel pump revealed superficial cracks on the dry side of the diaphragm of the engine-driven fuel pump, which initial testing revealed it incapable of sustaining engine operation but subsequent testing revealed it did allow engine operation; the auxiliary fuel pump tested satisfactory. No other discrepancies were identified during the engine examination. While the airplane was equipped with a ballistic recovery system parachute, the safety pin was not removed which contradicted the procedures in the Pilot Operating Handbook. Further, the location of the activation handle behind the co-pilot’s seat rendered it difficult to access for the pilot-in-command seated in the right seat during the uncontrolled descent. While the left seat occupant indicated with the operator that his weight was 275 pounds, which was the same amount listed on his last FAA medical application from December 1989; the external examination indicated he weighed 340 pounds. The weight he did provide was 25 pounds in excess of the maximum weight allowed for the seat determined during design and testing. Further, the weight determined during the external examination resulted in the airplane being 64 pounds above maximum ramp weight at engine start. Although the left seat outboard attach structure separated during the impact sequence, that condition was attributed to the exceedance of the maximum allowed seat weight by 90 pounds. Although the airplane had been spin tested by the manufacturer, it was not approved for intentional spins. No determination could be made as to why the PIC was unable to recover from the inadvertent spin.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Not arming the parachute recovery system before flight.

NTSB coding

Evidence available

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  • 21 docket documents
View NTSB final reportView NTSB docket

Docket documents21

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