Aviation Accident Summaries

Aviation Accident Summary ERA15FA221

West Columbia, SC, USA

Aircraft #1

N42BR

BR LEGEND LLC TURBINE LEGEND

Analysis

The commercial pilot departed on a cross-country flight in the experimental, amateur-built, turboprop airplane. About 3 minutes after takeoff, the pilot initiated a return to the departure airport. About 6.8 nautical miles (nm) from the runway, at an altitude of about 6,500 ft mean sea level, the pilot declared an emergency, stating that he had "lost" the engine. Shortly thereafter, he informed air traffic control that the airplane had experienced a loss of fuel pressure. Witnesses saw the airplane collide with a tree and subsequently impact a pond about 1.2 nm from the runway. They reported no engine sound. Examination of the airplane revealed no evidence of preimpact failures or malfunctions of the flight controls that would have precluded normal operation. The landing gear and flaps were found retracted. There was no evidence of preimpact failure or malfunction of the engine core. The engine-driven fuel pump showed signs of internal cavitation, while the auxiliary fuel pump, which provided fuel under pressure to the engine-driven fuel pump, flowed nearly 48% less than specified by the manufacturer, and had an inconsistent/intermittent laboring sound during testing. Disassembly revealed an improperly-installed fitting, which resulted in the decreased fuel flow rate, a loss of fuel pressure, and a subsequent engine flame-out. Inspection also revealed that a component of the fuel pump had been replaced after manufacture, but there was no record of this maintenance in the airplane's logbooks. While it was not known if the pilot attempted to perform an air restart of the engine, a worn ignitor box and ignitor plug may have precluded a successful restart of the engine. Although the pilot descended the airplane at its published best glide airspeed in his attempt to return to the airport, because the airplane was not equipped with an electrically-operated feathering pump, the propeller blade angle remained where it was set when the engine flame-out occurred, which was likely flat pitch. The flat pitch of the propeller blades significantly decreased the airplane's engine-out glide ratio. Had the pilot promptly feathered the propeller blades to reduce drag following engine flame-out, or had the airplane been equipped with a feathering pump, it is likely the airplane would have been able to reach the intended runway and land uneventfully. Although an enlarged heart was noted during the autopsy and toxicological testing detected quinine, given that the pilot was actively controlling the airplane just before the accident, there is no evidence that a medical condition or use of quinine contributed to the pilot's inability to fly the airplane.

Factual Information

HISTORY OF FLIGHTOn May 23, 2015, about 0921 eastern daylight time, an experimental, amateur-built Turbine Legend, N42BR, collided with trees and a pond about 1.2 nautical miles (nm) 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 privately operated. Visual meteorological conditions prevailed at the time, and a visual flight rules (VFR) flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight, which originated about 7 minutes earlier from CAE, and was destined for Asheville Regional Airport (AVL), Asheville, North Carolina. Air traffic control (ATC) radar and voice communication information indicated that the pilot was cleared to taxi to runway 11 and was provided a VFR clearance. He subsequently contacted the local controller and advised he was ready to depart. At 0913:27, the controller cleared the flight for takeoff and instructed the pilot to turn left heading 050°, which he 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 airport. The pilot acknowledged the transmission and proceeded in a north-northwesterly direction until 0917:26, at which time the airplane turned left from its on-course heading and continued to climb. At 0917:56, the pilot declared a mayday, advising the controller that he, "…lost ah my engine." About this time, the airplane was 6.8 nm from the approach end of runway 11 and about 6,500 ft mean sea level (msl). Immediately after the mayday call, the controller asked what aircraft was declaring an emergency, to which pilot replied with the partial call sign and that he was, "trying to make it back to the field." Following the mayday transmission, the pilot turned to a southerly heading. The controller advised the pilot to enter the left base leg of the airport traffic pattern for runway 11, provided the altimeter setting, and indicated the wind was calm. Coordination between the Radar North controller and the local controller 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, and asked him if the airport was in sight, but the pilot did not reply. About 10 seconds later, the Radar North controller inquired, "and uh 42BR Columbia" to which the pilot replied, "Roger I have it in sight I think I can make it." The controller then instructed the pilot to make a straight-in approach to runway 11, and about 0919:02, the pilot advised the controller that he "…lost my fuel pressure." The pilot was cleared to land twice; however, he did not reply to either clearance, nor did he establish contact with the local controller. At 0921:06, the Radar North controller asked the local controller if she could see the airplane, to which the local controller 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 sound from the engine. Three witnesses saw the airplane bank left, and one of those said the airplane pitched up just before it struck the tree. None of the witnesses saw any smoke or fire trailing the airplane. PERSONNEL INFORMATIONThe 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 the use of corrective lenses. On the application for his last medical certificate, the pilot reported 10,000 hours total flight experience. Based on maintenance records, it was estimated that the pilot had accumulated about 430 hours in the accident airplane. Family members reported that the pilot was in excellent health and did not take any medication. AIRCRAFT INFORMATIONThe airplane was manufactured in 2003. The 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 that was 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 by a lever that connected via cable to a dual-acting propeller governor, although the feathering circuit at the propeller governor was blanked off with a plate and not available. The airplane was not equipped with an electrically-actuated feathering pump. Although propeller counterweights helped to increase pitch of the propeller blades in the event of oil system failure, they were ineffective in feathering the blades when the propeller was spinning at low rpm due to insufficient centrifugal force generated. According to the engine maintenance records, the last condition inspection in accordance with the FAA-Approved Turbine Legend Maintenance and Inspection Program was completed on November 29, 2014 at an airplane total time of 428.2 hours. Further review of the maintenance records revealed no entry related to removal of a feathering pump or installation of a plate on the feathering pump circuit at the propeller governor. The airplane's fuel system consisted of one integral fuel tank spanning the entire length of the wing, with a fuel filler cap at each wingtip; the standard tank configuration held about 100 gallons. Fuel was gravity-fed from each wing into a sump located on the bottom surface of the wing on the airplane centerline. Attached to the outlet fitting of the sump tank was a manually-activated shutoff valve, which connected via aluminum tubing and a flexible hose to an electrically-controlled auxiliary fuel pump. The outlet of the auxiliary fuel pump connected via a flexible hose to a canister fitted with a pleated paper element and a "T" fitting for reading fuel pressure, then via a flexible hose from the filter to the engine-driven fuel pump. METEOROLOGICAL INFORMATIONThe 0856 surface observation at CAE indicated wind variable at 3 knots, 10 statute miles visibility, and clear skies. The temperature and dew point were 19 and 12° C, respectively, and the altimeter setting was 30.39 inches of mercury. AIRPORT INFORMATIONThe airplane was manufactured in 2003. The 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 that was 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 by a lever that connected via cable to a dual-acting propeller governor, although the feathering circuit at the propeller governor was blanked off with a plate and not available. The airplane was not equipped with an electrically-actuated feathering pump. Although propeller counterweights helped to increase pitch of the propeller blades in the event of oil system failure, they were ineffective in feathering the blades when the propeller was spinning at low rpm due to insufficient centrifugal force generated. According to the engine maintenance records, the last condition inspection in accordance with the FAA-Approved Turbine Legend Maintenance and Inspection Program was completed on November 29, 2014 at an airplane total time of 428.2 hours. Further review of the maintenance records revealed no entry related to removal of a feathering pump or installation of a plate on the feathering pump circuit at the propeller governor. The airplane's fuel system consisted of one integral fuel tank spanning the entire length of the wing, with a fuel filler cap at each wingtip; the standard tank configuration held about 100 gallons. Fuel was gravity-fed from each wing into a sump located on the bottom surface of the wing on the airplane centerline. Attached to the outlet fitting of the sump tank was a manually-activated shutoff valve, which connected via aluminum tubing and a flexible hose to an electrically-controlled auxiliary fuel pump. The outlet of the auxiliary fuel pump connected via a flexible hose to a canister fitted with a pleated paper element and a "T" fitting for reading fuel pressure, then via a flexible hose from the filter to the engine-driven fuel pump. WRECKAGE AND IMPACT INFORMATIONThe airplane crashed in a pond located adjacent to houses in a residential area. The wreckage was recovered and transferred to a hangar located at Lexington County Airport at Pelion (6J0), Pelion, South Carolina. According to first responders and FAA personnel, the empennage was partially submerged in the water and was in an inverted position, with the airplane's nose on a magnetic heading of 032°. The wreckage location was about 1.24 nm and 279° from the approach end of runway 11 and about 600 ft south of the runway's final approach path. Further examination of the accident site area revealed no damage to unmarked powerlines located adjacent to the pond. A strong smell of jet fuel and fuel sheen were noted on the west end of the pond. Damage to the top of a pine tree was noted about 70 ft above ground level; the top of the tree was observed in the water adjacent to the tree. Pieces of curved acrylic material were at the base of the tree, and pieces of composite material were in the water at the west end of the pond. There was no evidence of any tree limbs cut by the propeller blades. Examination of the wreckage following recovery accounted for all primary and secondary flight controls. The one-piece wing was separated from the impact-damaged fuselage. The vertical and horizontal stabilizers remained attached, and the primary and secondary flight control surfaces remained attached to their respective attach points. With the rudder placed in the neutral position, the rudder trim tab was trailing edge left (tail left); with the elevator in the neutral position, the trim tab was positioned trailing edge up (tail up). Damage to the right horizontal stabilizer was noted on the outboard portion. The engine remained attached to the airframe by the engine mount and the propeller was separated from the engine. There was no evidence of fire. Examination of the wing revealed extensive impact damage, including fracture of the forward and aft spars of the left wing about 5 ft outboard of the landing gear attachment, and fracture of the aft spar of the right wing. Impact damage was also noted to the left and right ailerons and flaps. The right main landing gear was retracted, and the left main landing gear was extended, although the FAA inspector reported it was retracted when the airplane was recovered. The center section of the wing revealed the flap actuator remained attached to the aft side of the main spar and to the flap torque tube. Continuity was confirmed from the flap torque tube to the control surface for the left flap, but the right flap push/pull rod exhibited bending overload at the rod end. The flaps appeared retracted. The fuel vents of both integral wing tanks were clear of obstructions. Examination of the flight controls for pitch and yaw revealed both tandem seat controls remained connected and continuity was confirmed from each respective control surface to the cockpit controls. Examination of the aileron flight controls revealed rod ends remained connected for the left and right aileron attachments at the control stick, but both rod ends exhibited bending overload. The left aileron push/pull tube exhibited bending overload outboard of the landing gear location and about 12 inches inboard of the bellcrank near the control surface, but was continuous from the bellcrank to the control surface. The right aileron push/pull tube was continuous from the fracture near the control stick to the aileron control surface. Examination of the cockpit revealed the lap belt and shoulder harness of the front seat restraint remained latched, but the left side of the lap belt webbing was cut. The fuel shutoff valve was full in, and continuity was confirmed from the cockpit control to the valve. The auxiliary fuel pump switch was in the on position, and the auxiliary fuel boost pump circuit breaker was not tripped. Examination of the throttle quadrant revealed the engine control lever was in the aft position, the propeller control was in the aft position, and the fuel control lever was in the run position. The landing gear selector was in the up position. Examination of the fuselage fuel system revealed the sump tank was ruptured, and the fuel supply line from the sump tank was separated at the tank attach point. The manually-actuated shutoff valve was fully open at impact based on an impact mark from hardware attached to the lever and adjacent flat of a b-nut. The Facet-type fuel pump at the sump tank was dry, and the sump tank fuel cap was in place. The auxiliary fuel pump and a Facet-type pump associated with the sump fuel tank were connected electrically to a portable, 24-volt power source and both were operational. The auxiliary fuel pump with attached hoses and fittings, part number 2003-B, serial number 103252 was retained for operational testing at the manufacturer's facility. Examination of the engine revealed the propeller was separated from the propeller shaft. The right side of the firewall was damaged and pushed aft above the right lower engine mount. The fuel supply line from the auxiliary fuel pump to the fuel filter was tight at both ends. The fuel supply line from the filter outlet to the engine-driven fuel pump was tight at the filter and connected at the fuel pump; the B-nut at the fuel pump was safety wired. Approximately 1 ounce of straw-colored fuel consistent with jet fuel was drained from the fuel filter, while a drop of straw-colored fuel was noted in the threads of the inlet of the engine-driven fuel pump. A small amount of metal shavings were noted at the inlet of the engine-driven fuel pump, while a small amount of metal shavings, sludge, and a portion of a plastic tie wrap tip were noted at the inlet area of the fuel filter housing. The engine and ignition exciters were removed for further examination. Examination of the engine was performed at a facility in the US, while the fuel control unit, engine-driven fuel pump, and propeller governor were examined at the manufacturer's facility in the Czech Republic. There were no pre-existing mechanical anomalies issues found during the engine examination which would have prevented normal operation. Examination of the engine-driven fuel pump revealed evidence of internal cavitation. In addition, one of the two ignitor boxes displayed evidence of internal coil movement, consistent with too long a duty cycle, and the supporting insulation material on one of the ignitor plugs had disintegrated. Examination of the propeller revealed all bolts that secured the propeller to the propeller shaft were damaged consistent with pull-out. All three blades remained secured inside the propeller hub, and exhibited large radius aft bending about 30°, beginning midspan. Two of the three blades appeared to be in the low-pitch range position with the counterweights trapped by the spinner in the corresponding positions. The third blade was less than the low-pitch position, and the blade tip was torn. The trapping of the propeller spinner and the counterweights was consistent with the blades being in an un-feathered position. Examination of the propeller revealed no anomalies that may have prevented normal operation. ADDITIONAL INFORMATIONPerformance Study An NTSB Performance Study indicated that the pilot maintained the airplane's best glide speed of 130 knots following the emergency declaration and during the attempted return to the runway. The airplane's angle of attack (AOA) was between 1 and 2° before the pilot reported the loss of fuel pressure and between 5 and 10° after. Based on the radar

Probable Cause and Findings

An engine flame-out due to fuel starvation as the result of an improperly-installed auxiliary fuel pump fitting, and the pilot's failure to promptly feather the propeller following the engine-flame out, which resulted in decreased glide capability and impact with terrain. Contributing to the accident was the pilot's operation of the airplane with no emergency electric propeller feathering system.

 

Source: NTSB Aviation Accident Database

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