History of Flight
At about 1140 Hawaiian standard time on February 15, 2011, an AirBorne WindSport Edge XT-912-L weight-shift-control (WSC) light sport aircraft, registration N29EP, was substantially damaged when it impacted the water near Hanapepe, Hawaii. The sport pilot instructor and his student sustained fatal injuries. The aircraft sank in about 50 feet of water and was recovered 7 days after the accident. Big Sky Kaua’i was operating the aircraft under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local instructional flight. The aircraft departed from Port Allen Airport, Hanapepe, Hawaii, about 1045.
A witness on a coffee plantation observed the aircraft flying downslope towards the ocean. He described it as about 3 to 4 telephone poles in height above him. The coffee field sloped from about 200 feet to 100 feet in elevation, ending at a cliff that dropped straight to the ocean. The witness lost sight of the aircraft as it dipped below the cliff line flying nearly due south. He stated the aircraft appeared slightly lower than during previous flybys, but the engine sounded fine.
A witness on a fishing boat said the aircraft leveled off at about 50 feet above the water and turned approximately west towards Port Allen Airport. A witness in a kayak reported the aircraft was about 50 feet above the water when he heard the engine sputter and then "fire back up." Initially thinking the aircraft would land on water, he observed it turn straight up into the air, climb about 100 feet, then the engine went silent. The aircraft nosed straight down and impacted the ocean.
A third witness on shore saw the aircraft near the 100-foot-high cliff, about 50 feet above the water, facing out to sea. She heard the engine sputter, then the aircraft pulled up to a vertical nose-up attitude, climbed briefly, then the engine went "dead silent" and it fell straight down into the ocean. Several kayak witnesses noted only an oil slick at the impact location.
Personnel Information
The 55-year-old pilot held a sport pilot certificate and flight instructor for sport pilot in WSC aircraft. He did not have an FAA medical certificate; a current driver's license sufficed. He also held a repairman certificate for light sport airplanes and WSC aircraft. His flight logbook was never recovered, and no documentation of his flight experience was found.
The 49-year-old student did not have an FAA medical certificate. A friend reported the student had never flown in a WSC aircraft or small general aviation aircraft.
Aircraft Information
The single-engine, propeller-driven, two-seat tandem WSC aircraft was manufactured by AirBorne Windsports Pty. Ltd. on May 24, 2006. Its maximum takeoff gross weight was 992 pounds; empty weight 494 pounds. It was powered by a Rotax 912 UL four-stroke engine (80 horsepower). The aircraft had a pilot-passenger pod suspended by a triangular frame for weight-shift control. It was equipped with dual flight controls and a ballistic recovery parachute.
Passengers were provided with helmet/headset combinations with noise canceling and automatic inflatable personal flotation devices. The engine's fuel supply was in a molded plastic tank behind and under the aft occupant's seat, holding about 18.5 gallons; fuel consumption was 3 to 3.5 gallons per hour. A choke lever on the left side of the pilot's seat frame was used for starting only; forward movement was on/rich. The engine had two carburetors with built-in starting carburetors activated by the single choke lever.
The aircraft was purchased on February 25, 2010, and assembled in Hawaii on February 27, 2010. The last 100-hour condition inspection was completed on January 25, 2011, at 698 flight hours.
The Pilot's Operating Handbook (POH) prohibited aerobatic maneuvers, including spinning, whipstalls, stalled spiral descents, and negative G maneuvers. It also stated not to pitch nose up or down more than 45 degrees from the horizontal, and not to exceed 60 degrees of bank angle. Flight load factors were limited to 4.0 G positive; loads from 1.0 G positive to 0.0 G should be avoided; negative loads less than 0.0 G were prohibited.
Meteorological Information
At 1153, weather at Lihue Airport, 13 nautical miles northeast, reported wind from 110 degrees at 6 knots, visibility 9 statute miles, clear of clouds, temperature 77°F, dew point 70°F, altimeter 30.10 inches of Mercury. Two kayak witnesses stated there "was not much wind."
Wreckage and Impact Information
The aircraft was found in about 45 feet of water, 125 feet from shore. Occupants were removed the day after. Divers noted the ballistic recovery system (BRS) had not been activated. Six days later, the aircraft was recovered. During recovery, the BRS fired. Examination revealed wing frame damage to the left forward support tube, left wing tip, and left cross tube. The left side of the oil sump was deformed; the left main landing gear strut was bent inward, consistent with left-side water impact. The engine exhibited internal continuity and thumb compression on all cylinders. The choke was found frozen in the on position. Rotational scoring on the plastic flywheel cover indicated engine rotation at impact. Two of three propeller blades separated at the hub. The engine fired and rotated but did not run continuously. During teardown, corrosion from salt water immersion was noted, but no pre-impact abnormalities were found.
The Dacron fabric on the top side of the wing failed a pull test at between 600 and 675 grams; the POH specified a lower limit of 1,360 grams. The bottom side tested within limits.
Medical and Pathological Information
An autopsy of the pilot was conducted on February 18, 2011. Toxicology tests performed by FAA's CAMI were negative for carbon monoxide, cyanide, and drugs. Ethanol detected was determined to be from sources other than ingestion.
Additional Information
A WSC subject matter expert reported an identical aircraft experienced a rough-running engine after takeoff. She traced it to the backseat student inadvertently moving the choke to on/rich. The accident aircraft's choke was found in the on position.
A liability release form signed by the student on the accident date stated he understood and agreed to release Big Sky Kauai, LLC., from liability for participation in light sport aircraft flying.