History of Flight
On July 4, 2021, about 1722 central daylight time, a Focke-Wulf FWP-149D experimental airplane, N9145, was destroyed when it crashed near Killeen, Texas. The pilot sustained fatal injuries. The airplane was operating under 14 CFR Part 91 as a personal flight.
According to ADS-B track data, the flight departed New Braunfels Regional Airport (BAZ) at about 1634 on runway 13, heading north toward Skylark Field Airport (ILE) in Killeen. After attending a static display at the BAZ Fourth-of-July airshow, the pilot began the return flight.
At 1714:39, while about 12.9 nm south of ILE, the airplane descended from 3,600 ft msl. It turned left toward the northwest at 1715:30, then right to join the extended centerline for runway 1 at ILE at 1717:50, at 2,800 ft msl. Between 1716:55 and 1718:42, airspeed decreased from 113 KCAS to about 57 KCAS. At 1719:42, airspeed was 57 KCAS with a descent rate of 655 ft/min; 13 seconds later, airspeed was 59 KCAS and descent rate 735 ft/min. Over the next 1.3 minutes, airspeed increased to 68 KCAS and descent rate decreased to about 450 ft/min.
The final ADS-B point at 1721:39 recorded the airplane at 1,141 ft msl (about 345 ft agl) and 2.4 nm from the runway 1 displaced threshold, with airspeed 64 KCAS and descent rate 300 ft/min. The main wreckage was found 0.5 mile north of that point.
A commercial airline pilot reported hearing the pilot transmit on 121.5 MHz that he had lost his engine, was losing altitude, and was trying to reach Skylark. The pilot later stated he would not make the airport and requested emergency vehicles. An ELT signal was subsequently heard. A witness observed the airplane at about 300 ft agl and 50–60 knots with the engine sputtering; the wings rolled left and right two to three times before the airplane stalled with the left wing down and descended.
Aircraft Information
The German-built Focke-Wulf FWP-149D was originally a military trainer not FAA type-certificated. It operated in the United States from 1994 to 2001 with an experimental exhibition certificate, then was exported to Canada for refurbishment and operation until August 2019. On August 31, 2019, it re-entered the United States with a Canadian registration and experimental certificate. On September 23, 2019, the FAA issued a new experimental exhibition airworthiness certificate, and the airplane was re-registered as N9145. At that time, airframe total time (AFTT) was 2,454.6 hours and engine time since overhaul (TSOH) was 497.5 hours.
Recent maintenance: The last condition and 100-hour inspections were completed on September 8, 2020 (AFTT 2,512.8 hours, TSOH 557.7 hours). The pilot's logbook noted a "chip light" illumination on October 24, 2020, with no associated maintenance found. On June 19, 2021, the chip light illuminated again along with an unspecified magneto issue. The pilot relocated the airplane to Draughon-Miller Central Texas Regional Airport (TPL) on June 21 for repair by his mechanic. The mechanic found the right magneto needed repair, which was overhauled by a shop on June 29. Additional tasks included oil change, oil filler neck repair, and new gaskets for the propeller governor and adapter plate. On July 2, 2021, the mechanic installed the repaired magneto and completed an engine run, during which the amber "chip detector" warning light illuminated. He shut down, drained the oil, and found metal contamination in the oil filtration system. The contamination was non-magnetic. The mechanic and pilot agreed to send samples to a laboratory for analysis. The mechanic told the pilot not to fly until the source was determined. The pilot, however, stated he intended to fly the airplane back to ILE. After cleaning the filtration system and adding new oil, a subsequent engine run showed no chip light. The last logbook entry (July 2) recorded AFTT 2,577.7 hours and TSOH 620.6 hours.
On July 3, 2021, the pilot repositioned the airplane from TPL to ILE (0.2 hours flight). The mechanic believed the airplane would remain at ILE pending laboratory results. On July 4, the pilot flew to BAZ (0.8 hours non-stop) for the airshow display. The accident occurred on the return flight to ILE (also 0.8 hours). The tachometer was destroyed in the post-crash fire; using logbook and ADS-B data, the accident AFTT and TSOH were calculated at 2,579.5 hours and 622.4 hours, respectively.
The airplane was equipped with an Aviation Development Corporation (ADC) oil filtration system (part number 600010-1). The system included a ball-and-spring bypass switch that could illuminate a cockpit warning light when oil bypassed the filter screen. A separate magnetic chip detector was optional but not installed on this airplane.
Wreckage and Impact Information
The main wreckage came to rest in a level grass field with trees. The initial impact ground scar contained red navigation light lens fragments, consistent with a left-wing-low attitude. The debris path was oriented on a 319° true heading, about 135 ft long. The main wreckage comprised the cabin/cockpit, right wing, aft fuselage, engine, and propeller. The cabin and cockpit were destroyed by impact and post-impact fire. All structural components and flight controls were present at the site; damage was consistent with ground impact. Flight control continuity could not be established due to extensive damage, but observed separations were consistent with impact, fire, or recovery cuts.
The engine could not be rotated via the propeller. Disassembly revealed that Nos. 3 and 4 connecting rods had separated from their crankshaft journals; their beams were bent, twisted, and deformed. There was significant internal damage to the crankcase, especially along the rotational plane of those rods and associated components. No evidence of heat distress or lack of lubrication was found. Cylinder combustion chambers were undamaged, with no foreign object ingestion or detonation. The oil sump had a large hole from thermal damage.
Examination determined that one of two crankshaft dynamic counterweights separated from its mounting lobe at position No. 3. That mounting lobe had elongated bores and a tearing/bending appearance. Fractured metal items recovered from the crankcase, cylinders 3 and 4, and oil sump included pieces of connecting caps, bolts, nuts, bearings, counterweights, mounting lobes, rollers, bushings, snap rings, and washers. Counterweight rollers showed fretting/galling at their center bushing surfaces.
These items were examined at the NTSB Materials Laboratory. Three items had curved surfaces, case cracking, and material composition consistent with type 4340 steel alloy used for crankshafts. Their curved surfaces matched counterweight mounting lobe geometry. Case cracking was consistent with nitrided type 4340 steel. One counterweight lobe piece exhibited overstress fracture on the left side and progressive fracture on the right side; other lobe pieces showed progressive fracture features on both sides, consistent with fatigue failure. The remaining items showed gross plastic deformation, batter, and overstress features.
Additionally, the contamination collected from the oil filter on July 2, 2021, was analyzed. Particles ranged from 0.01 inch to less than 0.001 inch, with flat or ovoid morphology. EDS analysis found primary elements: carbon, oxygen, aluminum, iron, copper, and lead. Aluminum and iron particles were flat or plate-like, consistent with skiving or milling. Iron composition matched chromium or chromium-molybdenum steel (counterweights are fabricated from such steel). Particles with high lead and bromine were fuel additive vestiges. Aluminum particles were consistent with an aluminum alloy with minor magnesium.
Medical and Pathological Information
An autopsy of the pilot was performed by the Southwestern Institute of Forensic Sciences in Dallas, Texas. The cause of death was thermal and blunt force injuries, and the manner of death was accident. FAA toxicology testing detected no carboxyhemoglobin, ethanol, glucose, or tested-for drugs.