History of Flight
On March 11, 2014, at approximately 0910 Hawaiian standard time, a special light-sport weight-shift-control trike, Revo Evolution Trikes model, registration N98EV, impacted terrain near Kekaha, Hawaii, and was consumed by fire. The aircraft was operated by Birds in Paradise, LLC, under Title 14 Code of Federal Regulations Part 91 as an instructional flight. The certified flight instructor and student pilot sustained fatal injuries; the trike was destroyed. Visual meteorological conditions prevailed, and no flight plan was filed.
The flight departed Port Allen Airport in Hanapepe, Hawaii, around 0850. The introductory flight was planned to last 60 minutes before returning to the airport. Another certified flight instructor (CFI) from the same company was flying a second trike in close proximity. He reported meeting the accident pilot at the company facilities about 0615, where they prepared the trikes and greeted their student pilots. After fitting the students with flight suits and helmets, they departed around 0850.
Shortly after departure, the accident pilot informed the second pilot that they would communicate on the company frequency, 123.450. This was the last transmission received from the accident pilot. As they approached the Barking Sands class D airspace, the second pilot switched to the Barking Sands frequency to request clearance for a flight of two. When the CFI's trike reached the northwest side of Polihale Beach at about 600 feet above ground level (agl), he observed the accident trike at approximately 1,000 feet agl and 75 feet horizontally to his 1-o'clock position. This was the last sighting of the accident trike around 0910. After performing two near-360-degree turns over the ocean and attempting to contact the accident pilot, the CFI noticed smoke at the base of the ridgeline and maneuvered to the area, where the accident trike was fully engulfed in flames.
Personnel Information
Federal Aviation Administration (FAA) records indicated the 54-year-old pilot held a certified flight instructor sport-pilot certificate. According to the pilot's partner, he had accumulated 19,000 flight hours and was well-known in the trike community. He was not required to hold a medical certificate for sport pilot or flight instructor privileges and possessed a light-sport repairman certificate.
The pilot had flown four flights totaling 5.5 hours on March 8, 2014. On March 10, he made several flights before returning home at 1600. He received 7-8 hours of sleep and arrived at the flight school around 0600 on the accident day. Customers typically arrived about 0645, with the first flight at 0700. Flights were either 60 or 90 minutes and were always conducted as tandem flights with both pilots maintaining radio communication.
Aircraft Information
The trike was a special light-sport weight-shift-control Evolution Trikes Revo, serial number 000551, equipped with a Rotax 912ULS engine, serial number 6775546. Maintenance logbooks showed the last airframe conditional inspection on December 19, 2013, at 1,427 hours total time, and the last engine conditional inspection on January 3, 2014, at 1,442 hours.
The same trike and pilot were involved in a previous accident in April 2010 (NTSB number WPR10CA224), where a loss of engine power resulted from fuel exhaustion due to the pilot's decision to continue after a low fuel warning. The trike had 24 hours of total time at that point and was rebuilt.
Recent History
The pilot had recently experienced fuel system issues. He reported to the second pilot that fuel was being suctioned out of the main vent line located in the belly of the aircraft. On a flight about one month before the accident (approximately 25 flights prior), he landed in Princeville, Kauai, to assess the problem. He attributed the fuel streaming to suction from the vent line's position in the airstream. It was unknown when the issue began, as the vent line position had not been changed according to records.
About a week before the accident, the pilot spoke with a representative from Evolution Trikes about fuel being siphoned during flight, noting the fuel level was diminishing quickly and another pilot observed fuel streaming. The representative suggested the fuel was heating inside the tank due to its position near the radiator and exhaust, causing expansion and about a half-gallon to stream out. The pilot had re-routed the vent line up the mast, but it still leaked. The representative stated that all fuel vent lines on the company's Revo models showed signs of leakage.
On the accident morning, the second pilot saw the accident pilot on a ladder routing compressed air into the trike's fuel vent line. The second pilot noted the fuel cap was still on and removed it, producing a "pop" sound as compressed air escaped. The pilot had re-routed the clear plastic vent line up the mast, then aft along the keel inside the keel pocket, bent 180 degrees upward and forward facing into the airstream, secured to the left side of the keel tube with tie-wraps and black tape. The accident flight was the first with this configuration.
Fuel System
The fuel system had a single saddle-style aluminum tank with a capacity of 14.5 gallons. A brass T-fitting was threaded into the tank about 2 inches in front of a large filler hose to the gas cap. The two lower saddles were coupled with a T-fitting and 90-degree elbows. As originally installed, the vent tube went from the tee about 4 inches over the filler tube and then ran 3 feet out the bottom. The mechanical fuel pump was located above the tank, making it susceptible to vapor lock if low pressure existed. An electric fuel pump was mounted below the fuel level but could not force fuel if the vent was plugged.
According to the airframe manufacturer, filling the tank to maximum capacity could allow the vent tube to fill, and during a steep climb, fuel could spill over the high point and siphon out all fuel above the T-fitting. If compressed air was introduced into the vent tube, it would pressurize the system, exacerbated by heat expansion. The tank was pressure tested to 3 PSI. The manufacturer also stated that during flight, the keel tube could pinch the vent line, and if blocked, the engine would run about 15 minutes before fuel starvation from vacuum.
An engine manufacturer representative noted that a blocked vent line could cause fuel tank pressurization from the return line, compounded by the electric boost pump, potentially overpressurizing the carburetor float bowl. He stated pressurization could only occur if the venting system was blocked and something simultaneously pressurized the tank.
Meteorological Information
The nearest weather observation station at Barking Sands Pacific Missile Range Facility Airport, about 2 nautical miles south, reported at 0856: wind calm, visibility 10 miles or greater, clear skies, temperature 21°C, dew point 19°C, altimeter 30.05 inches of mercury.
Additional Information
A GoPro camera recovered from the wreckage had sustained significant impact damage; the battery and memory card were dislodged. The memory chip was cracked, and data could not be recovered.
Three prior fatal weight-shift trike accidents during instructional flights had occurred in Hawaii: WPR10FA211, WPR11FA138, and WPR11FA225.
Federal regulations (14 CFR 91.327) limit compensation or hire operations of light-sport aircraft to towing gliders or conducting flight training. Birds in Paradise used special light-sport aircraft for introductory flights, advertising as an "Intro Flight School." A previous investigation (WPR11LA081) found that operators were conducting flight tours under the guise of instruction, with no follow-up training or repeat students, and the Honolulu Flight Standards District Office was aware but had limited resources for surveillance.
An autopsy determined the pilot's cause of death as multiple traumatic injuries; toxicology tests were negative for ethanol and tested drugs.
The wreckage came to rest at the base of a ridgeline about 1 nautical mile east of Polihale State Park. The main wreckage was consumed by fire, but all major components were present. The airframe manufacturer noted that the haul-back latch position and damage to cross tubes indicated the wing impacted terrain in a near-vertical attitude. There was no evidence of system malfunction. The keel end portions and fuel vent line were found still secured with black tape.