N327SH

HISTORY OF FLIGHTOn 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 3 weeks 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. PERSONNEL INFORMATIONThe 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. AIRCRAFT INFORMATIONThe 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. METEOROLOGICAL INFORMATIONA 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. AIRPORT INFORMATIONThe 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. WRECKAGE AND IMPACT INFORMATIONThe main wreckage came to rest in a wooded area. The majority of the airplane was severely fragmented, and the major components were 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. ADDITIONAL INFORMATIONSimilar 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 brack...