History of Flight
On May 23, 2015, about 0921 eastern daylight time, an experimental, amateur-built Turbine Legend, N42BR, collided with trees and a pond approximately 1.2 nautical miles west of Columbia Metropolitan Airport (CAE), West Columbia, South Carolina. The airplane was destroyed and the commercial pilot was fatally injured. The airplane was registered to BR Legend, LLC and operated as a personal flight under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and the pilot had filed a visual flight rules (VFR) flight plan. The flight originated from CAE about 7 minutes earlier, destined for Asheville Regional Airport (AVL), Asheville, North Carolina.
Air traffic control (ATC) radar and voice communications indicated that the pilot was cleared to taxi to runway 11 and provided a VFR clearance. He contacted the local controller and advised readiness to depart. At 0913:27, the controller cleared the flight for takeoff, instructing a left turn to heading 050°, which the pilot acknowledged. Shortly after takeoff, ATC communications were transferred to departure control.
The flight was radar-identified at 0914:56, and the pilot was instructed to turn left on course toward the destination. The pilot acknowledged and proceeded north-northwest until 0917:26, when the airplane turned left from its on-course heading and continued climbing. At 0917:56, the pilot declared a mayday, stating he had lost his engine. At that time, the airplane was about 6.8 nm from the approach end of runway 11 and about 6,500 ft mean sea level (msl). The controller asked for identification, and the pilot replied with a partial call sign and that he was trying to return to the field. He then turned to a southerly heading.
The controller advised the pilot to enter left base for runway 11, provided the altimeter setting, and reported calm wind. Coordination between controllers occurred, and at 0918:41, the Radar North controller advised the pilot that CAE was at his 10-to-9 o'clock position and 6 miles, asking if the airport was in sight. The pilot did not reply. About 10 seconds later, the controller inquired again, and the pilot replied, "Roger I have it in sight I think I can make it." The controller then instructed a straight-in approach to runway 11. At about 0919:02, the pilot advised that he had lost fuel pressure.
The pilot was cleared to land twice but did not reply. At 0921:06, the Radar North controller asked the local controller if she could see the airplane; she responded that the airplane was on short final and she was giving the green light-gun signal to land. Witnesses reported seeing the airplane impact trees and then a pond; they did not hear any engine sound. Three witnesses observed the airplane bank left, and one said the airplane pitched up just before striking the tree. No smoke or fire was seen.
Personnel Information
The pilot, age 85, held a Federal Aviation Administration (FAA) commercial pilot certificate with ratings for airplane single- and multi-engine land and instrument airplane. He was issued a second-class medical certificate on February 5, 2015, with a limitation requiring corrective lenses. He reported 10,000 hours total flight experience on his last medical application, and an estimated 430 hours in the accident airplane based on maintenance records. Family members reported the pilot was in excellent health and did not take any medication.
Aircraft Information
The airplane was manufactured in 2003. Its special airworthiness certificate was issued by an FAA Designated Airworthiness Representative (DAR), who also assisted the pilot with building a portion of the airplane. It was powered by a Walters M601D turbine engine equipped with a three-bladed Avia V508E-AG/99B/A constant speed, variable pitch, manual feathering, dual-acting, hydraulically-controlled propeller. Propeller blade angle was controlled from the cockpit; however, the feathering circuit at the propeller governor was blanked off with a plate and not available. The airplane lacked an electrically-actuated feathering pump. Propeller counterweights could increase blade pitch in case of oil system failure but were ineffective for feathering at low rpm due to insufficient centrifugal force.
The last condition inspection, per the FAA-Approved Turbine Legend Maintenance and Inspection Program, was completed on November 29, 2014, at an airplane total time of 428.2 hours. No maintenance entry was found regarding removal of a feathering pump or installation of the plate on the feathering pump circuit.
The fuel system comprised one integral fuel tank spanning the wing length, with filler caps at each wingtip; standard capacity was about 100 gallons. Fuel gravity-fed from each wing into a sump on the wing centerline. A manually-activated shutoff valve connected to an electrically-controlled auxiliary fuel pump, then to a canister with a pleated paper element and a "T" fitting for fuel pressure reading, then to the engine-driven fuel pump.
Meteorological Information
The 0856 surface observation at CAE indicated wind variable at 3 knots, visibility 10 statute miles, clear skies. Temperature was 19°C, dew point 12°C, and altimeter 30.39 inches of mercury.
Wreckage and Impact Information
The airplane crashed in a pond adjacent to houses in a residential area. The wreckage was recovered and moved to a hangar at Lexington County Airport at Pelion (6J0), South Carolina. First responders and FAA personnel noted the empennage partially submerged and inverted, with the nose on a magnetic heading of 032°. The wreckage location was about 1.24 nm and 279° from the approach end of runway 11, about 600 ft south of the final approach path. No damage to unmarked powerlines adjacent to the pond was observed. A strong smell of jet fuel and a fuel sheen were present on the west end of the pond. A pine tree top about 70 ft above ground level was damaged; its top was in the water. Pieces of curved acrylic and composite material were found. No evidence of tree limbs cut by propeller blades was noted.
All primary and secondary flight controls were accounted for. The one-piece wing separated from the fuselage. Vertical and horizontal stabilizers remained attached. Flight control surfaces remained attached. Rudder trim tab was trailing edge left; elevator trim tab was trailing edge up. The right horizontal stabilizer had outboard damage. The engine remained attached by the mount; the propeller separated. No fire evidence was found.
Wing examination revealed extensive impact damage, including fractures of forward and aft spars. The right main landing gear was retracted; the left main landing gear was extended (though the FAA inspector reported it retracted on recovery). Flaps appeared retracted. Fuel vents were clear. Flight control continuity was confirmed. Cockpit examination showed the front seat lap belt and shoulder harness latched; the left lap belt webbing was cut. The fuel shutoff valve was full in; auxiliary fuel pump switch was on; its circuit breaker was not tripped. The throttle quadrant showed the engine control lever aft, propeller control aft, fuel control lever in run, and landing gear selector up.
The fuselage fuel sump tank was ruptured; the fuel supply line separated at the tank attach point. The manually-actuated shutoff valve was fully open at impact based on an impact mark. The Facet-type pump at the sump was dry; the sump cap was in place. The auxiliary fuel pump and sump pump were tested with a portable 24-volt source and both operated. The auxiliary fuel pump (part number 2003-B, serial number 103252) was retained for testing.
Engine examination revealed the propeller separated from the propeller shaft. The fuel supply line from the auxiliary pump to the filter was tight; the line from the filter to the engine-driven pump was tight and safety-wired. About 1 ounce of straw-colored fuel (consistent with jet fuel) was drained from the filter; a drop was noted at the engine-driven pump inlet. Small metal shavings were at the pump inlet; metal shavings, sludge, and a portion of a plastic tie wrap tip were at the filter housing inlet. The engine and ignition exciters were removed for further examination.
The engine was examined in the US; the fuel control unit, engine-driven fuel pump, and propeller governor were examined in the Czech Republic. No pre-existing mechanical anomalies were found that would have prevented normal operation. The engine-driven fuel pump showed evidence of internal cavitation. One of two ignitor boxes displayed evidence of internal coil movement consistent with too long a duty cycle; supporting insulation on one ignitor plug had disintegrated.
Propeller examination revealed all bolts securing it to the shaft were damaged consistent with pull-out. All three blades remained in the hub and exhibited large radius aft bending about 30° beginning midspan. Two blades appeared in the low-pitch range with counterweights trapped by the spinner; the third blade was less than low-pitch and its tip was torn. The trapping was consistent with an un-feathered position. No propeller anomalies were found.
Additional Information
An NTSB Performance Study indicated the pilot maintained best glide speed of 130 knots after the mayday and during the attempted return. The airplane's angle of attack (AOA) was between 1 and 2° before the pilot reported loss of fuel pressure and between 5 and 10° after. Based on radar data, the glide ratio was estimated at 7.5; with a feathered propeller, it would have been 12.0, resulting in a power-off glide distance of about 12.8 nm from 6,500 ft.
Flight Recorders
The airplane was equipped with digital instruments recording engine parameters including N1, N2, torque, inter-turbine temperature (ITT), oil pressure/temperature, and fuel level. Data from the last power cycle were recovered. Three recorded values for oil pressure and temperature corresponded to elapsed times; all oil pressure readings (17, 34, 31 psi) and last two oil temperatures (49°C, 57°C) were within limits. Torque values at 218, 436, and 654 seconds were 14%, 78%, and 17%, respectively. ITT values at 217, 434, and 651 seconds were 485°C, 620°C, and 410°C. Only one N1 (58.4%) and N2 (1950 rpm) value was logged at 163 seconds. The elapsed time from first ground contact (0909:37) to last visual sighting (0921:07) was 690 seconds, but correlation to real time could not be made due to unknown engine start time.
Medical and Pathological Information
A postmortem examination by Newberry Pathology Associates listed the cause of death as multiple blunt force injuries. The heart weighed 560 grams. Forensic toxicology by the FAA Bioaeronautical Sciences Research Laboratory was negative for carbon monoxide and volatiles; unquantified Quinine was detected in urine and iliac blood specimens.
Tests and Research
The auxiliary fuel pump was examined and operationally tested at the manufacturer's facility. One motor brush cap was red, indicating non-factory parts. With 28-volt supply, outlet flow was 55 gallons per hour (gph), below the factory requirement of 105 gph. The pump outlet adapter fitting was installed deeper than allowed, restricting the internal no-return poppet valve. After removal of the incorrectly-installed adapter, pump performance was 109 gph. During vacuum testing, the motor had an inconsistent/intermittent laboring sound. No maintenance record of removal, replacement, or repair of the auxiliary fuel pump was found.
Examination of the annunciator panel showed all bulb filaments intact with no evidence of stretching.
Review of the Pilot Information Handbook revealed an emergency checklist titled "Engine Flame-out In Flight." The first step specified moving the propeller control lever (PCL) to the feather position. The checklist stated to maintain a minimum airspeed of 130 knots indicated if at low altitude.
According to FAA Order 8130.2H, aircraft inspection guidelines for special airworthiness certificates specify that flight controls should operate properly and that engines, propellers, and associated instruments operate per manufacturer's instructions. There was no mention for a Designated Airworthiness Representative to determine compatibility of airframe, engine, and propeller systems related to emergency systems. FAA Advisory Circulars AC 20-27G and AC 90-89B provided no guidance for experimental aircraft builders regarding turbine engine installation considerations.