ERA17FA038

The student pilot and flight instructor were conducting an instructional flight in an experimental amateur-built airplane about 3/4 mile east of the departure airport in light winds with no adverse weather nearby. The investigation could not determine which of the pilots was flying the airplane at the time of the accident. One witness reported hearing the engine noise decrease before seeing the airplane descend and then abruptly pitch up and hearing the engine noise increase. He then heard a loud sound and saw a wing separate from the fuselage. Subsequently, the airplane entered an uncontrolled descent and impacted trees and terrain. Another witness reported seeing the airplane flying overhead and hearing the engine running. He also saw a parachute trailing behind the airplane while it was descending. Examination of the wreckage revealed that both the forward and aft right wing "Rony" attachment brackets had failed. The brackets were separated from the root tube and the root tube was fractured on all four sides at the aft wing attachment bracket mounting holes. All the attachment brackets and root tube fracture surfaces were consistent with overload failure and showed no evidence of preexisting damage, cracks, or corrosion. Examination of the engine revealed no evidence of any preimpact mechanical failures or malfunctions that would have precluded normal operation. Although the ballistic recovery airframe parachute system was found deployed, the airplane impacted tress before the parachute could inflate. The airplane had been involved in a hard landing about 1 week before the accident. Two days before the accident, the student, who had previously been an airplane mechanic in the U.S. Navy, replaced a steel cable between the two landing gear legs, which had been broken during the hard landing. However, no evidence was found indicating that the hard landing or the repairs contributed to the failure of the right wing attachment brackets and subsequent wing separation. Although the toxicology testing of specimens from the flight instructor detected hydrocodone in the liver, the investigation could not determine whether the flight instructor's use of hydrocodone before the flight contributed to the accident. Although ethanol was detected in the student's muscle, it was not detected in the liver, and no n-propanol was detected in the liver, which is consistent with postmortem production of ethanol. Given the witness's statement and the wreckage evidence, it is likely the airplane was pitched up abruptly following a descent, which resulted in the in-flight separation of the right wing and the subsequent uncontrolled descent.

Similar Accidents A review of the National Transportation Safety Board aviation accident database revealed four other Quad City Challenger II accidents involving in-flight wing attachment bracket failures that led to in-flight wing separations (MIA04LA068, WPR09LA453, SEA07LA155, and CEN11LA050). Three of these accidents were fatal. In the nonfatal accident, the pilot successfully deployed a ballistic parachute and was not injured. Two of the accidents involved overload failures of wing attachment bracket(s): one of which occurred during an abrupt pitch-up maneuver after a dive/descent, and the other of which occurred after a section of fabric had separated from the wing, which caused a high drag load on the wing. In the third accident, a lift strut attachment bracket (same material and shape as the wing attachment bracket, but slightly smaller in size) likely failed due to overtightening and/or use of an incorrect bolt. The fourth accident involved the separation of a wing attachment bracket for undetermined reasons. The tandem, two-seat, high-wing airplane was built from a kit manufactured by Quad City Ultralight Aircraft Corporation and was constructed of tubes and fabric. It was powered by a 52-horsepower Rotax 503 dual-carburetor, two-cycle engine, which was equipped with a carbon fiber, two-blade, fixed-pitch propeller in a pusher configuration. The airplane was equipped with a ballistic recovery airframe parachute system. The airplane was issued an operating special airworthiness certificate on September 4, 2008. According to the airplane's maintenance records, the most recent condition inspection was performed on June 14, 2016, at which time the airplane and engine had accrued 124 flight hours. The airplane had flown about 18 hours since that inspection, and the electronic recording tachometer read 142 hours at the accident site. The student's friend stated that the airplane had been involved in a "hard landing" about a week before the accident, which resulted in the main landing gear being "splayed out" and a steel cable that ran between the landing gear under the fuselage breaking. The student replaced the cable himself 2 days before the accident. The friend indicated that that the student had previously been an airplane mechanic in the U.S. Navy. On November 9, 2016, at 0913 eastern standard time, an experimental amateur-built Challenger II airplane, N327SH, was destroyed during an in-flight breakup in Crescent City, Florida. The flight instructor and student pilot were fatally injured. The airplane was registered to the Juguetes, LLC, and the instructional flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed near the accident site, and no flight plan was filed for the local flight, which departed Skinners Wholesale Nursery Airport, Crescent City, Florida, about 0815. According to a friend of the student pilot, the student purchased the airplane about 3weeks before the accident. He stated that the student had flown with the flight instructor in the accident airplane at least twice. According to the student's wife, the airplane belonged to a company that employed the student, and he had purchased it on behalf of the company. During the accident flight, the student was seated in the front seat, and flight instructor was seated in the rear seat. The investigation could not determine which pilot was flying the airplane at the time of the accident. A witness stated that, while outside in his front yard, which was located about 1,000 ft from the accident site, he saw the airplane flying toward him on a southerly heading above the trees on his neighbor's property. He added that he heard the engine noise decrease "as if to idle speed" and then saw the airplane begin to descend "as if it were gliding." A few seconds later, he saw the airplane suddenly pitch up and heard the engine noise become "very loud like full power…as if the airplane were trying to go up." He then heard a loud sound and saw a wing separate from the fuselage. Subsequently, the airplane went straight down into trees. He added that the wing continued moving briefly toward the south and then landed in his front yard, about 30 ft away from him. Another witness, who was located about 500 ft east of the accident site, stated that he first saw the airplane flying "way above the trees" and that he heard the engine running. He also saw an uninflated parachute trailing behind the airplane as it was descending. He said that he saw no explosion nor fire and that he did not see anything separate from the airplane. The District 23 Medical Examiner's Office, St. Augustine, Florida, conducted autopsies of the flight instructor and student. The cause of death for both was determined to be "multiple blunt force injuries." The laboratory at FAA Forensic Sciences, Oklahoma City, Oklahoma, conducted forensic toxicology testing on specimens from the flight instructor. The FAA toxicology testing detected 0.138 (µg/ml, µg/g) hydrocodone in liver and 0.026 (µg/ml, µg/g) of its active metabolite dihydrocodeine in liver, 0.034 (µg/ml, µg/g) hydrocodone in muscle, and metoprolol in liver and muscle. NMS Labs, Willow Grove, Pennsylvania, also conducted toxicology testing on specimens from the flight instructor. The testing detected 190 (ng/g) hydrocodone in liver. Hydrocodone is an opioid prescribed as a Schedule II controlled substance. It is considered impairing and has psychomotor, sedative, and judgement effects. There is no direct way to convert postmortem liver levels of hydrocodone into premortem levels. Regular users of hydrocodone can develop significant tolerance to the impairing effects; therefore, the amount of it found in the blood cannot lead to a determination of the degree of impairment. Metoprolol is a blood pressure medication that is not considered impairing. FAA and NMS Labs also conducted forensic toxicology testing on specimens from thestudent pilot. The FAA toxicology testing detected atorvastatin in liver but not in muscle, metoprolol in liver and muscle, telmisartan in liver, n-propanol in muscle, and ethanol in muscle (42 mg/dl). No ethanol was detected in liver. The NMS testing was negative for tested compounds. Atorvastatin is a cholesterol-lowering agent, and telmisartan is a blood pressure medication; neither of which is considered impairing. Ethanol is an intoxicant, which, after absorption, is uniformly distributed throughout all tissue and body fluids. A small amount of ethanol can be produced in postmortem tissue by microbial action, often in conjunction other alcohols, including n-propanol. A 0850 surface observation weather report from Ormond Beach Municipal, Ormond Beach, Florida, located about 22 nautical miles northwest of the accident site, included wind from 320° at 5 knots, visibility 10 statute miles, broken clouds at 7,000 ft, temperature 18°C, dew point 17°C, and an altimeter setting of 30.09 inches of mercury. The flight instructor held a sport pilot certificate with an airplane single engine land rating. He also held a flight instructor certificate with a sport pilot rating and an endorsement for airplane single-engine. His flight instructor certificate was renewed on November 16, 2015. According to his logbook, he had 343 hours of total flight experience. Between December 2015 and October 2016, he flew 25 hours in the same make and model airplane as the accident airplane. His logbook records before that time were not found; however, he had owned an airplane of the same make and model as the accident airplane since May 2010. The student pilot did not have a Federal Aviation Administration (FAA) medical certificate or student pilot certificate. According to his logbook, he had received a total of 12 hours of flight instruction, all of which were logged between March 2015 and April 2016 and all of which were in the same make and model airplane as the accident airplane. According to the student's friend, the student considered flying to be a hobby. He had flown regularly with the flight instructor and received dual instruction; however, he did not intend to earn a pilot certificate. A handheld GPS unit, was forwarded to the NTSB laboratory, Washington, DC, for further examination. Data were recovered from the unit, however the most recent flight recorded occurred on October 20, 2016, and none of the accident flight was captured. The unit stored GPS parameters for flights dating back to May, 2010. Of all the flights recorded, the highest groundspeed (75 mph) was recorded during the last flight stored on the unit, on October 20, 2016. The airspeed indicator in the instrument panel was labeled with a mark for Vne (never exceed speed) at 80 mph, and Va (maneuvering speed) at 70 mph. The kit manufacturer's design Vne speed is 100 mph. The main wreckage came to rest in a wooded area. The majority of the airplane was severely fragmented, and the major componentswere found separated from the fuselage and damaged. Portions of the left wing had come to rest in a tree that was about 30ft-tall. The right wing was found largely intact about 1,000 ft south of the main wreckage. Wing fabric fragments and wing strut fairing fragments were strewn throughout a neighborhood south of the right wing's location. The airframe parachute was found opened in the main wreckage, and the expended rocket motor and parachute sleeve were found in a tree about 600 ft southeast of the main wreckage. All flight control surfaces and major components were present, with the exception of a portion of one wing-attach bracket and a short section of the forward right wing spar. Flight control continuity could not be confirmed due to the extent of impact damage. The two right wing lift struts (forward and aft) were fractured about midspan, and the ends of each lift strut remained attached to the fuselage and the right wing. The two right wing attachment brackets ("Rony" brackets), located on a centerline aluminum square beam at the top of the fuselage (the "root tube"), were fractured and separated from the root tube. A portion of the forward attachment bracket and inboard section of the forward wing spar were not found. The root tube was fractured on all four sides at the aft wing attachment bracket mounting holes. The attachment brackets and root tube sections were examined with microscopes. All the attachment brackets and root tube fracture surfaces were consistent with overload failure and showed no evidence of preexisting damage, cracks, or corrosion. The engine sustained impact damage, and the two propeller blades were both fracture-separated about 10 inches from the root. The engine was rotated by hand with some binding noted. An accessory pulley was damaged and impinging on the engine case. Both pistons were observed through the intake manifolds and moved as the engine was rotated. The two carburetors remained together as a unit, but the air filter was separated from the engine. One carburetor's float bowl was separated and missing, the main jet housing was fractured, and the jet was missing. The other carburetor's float bowl was removed; the floats were intact, and the bowl was dry. A small amount of liquid consistent with the color of automobile gasoline was present in the inline fuel filter. One spark plug was fractured and could not be removed. The remaining three sparkplugs were removed; all electrodes were intact, and each exhibited tan and black coloration.