Mokuleia, HI, USA
N444EZ
AIRBORNE WINDSPORTS Edge XT-912L
The flight instructor and student were conducting a local area discovery flight in the weight-shift-control light sport aircraft. An onboard video of the accident flight and ADS-B data revealed that about 28 minutes into the flight the aircraft entered a right turn as the flight instructor stated another way for them to lose altitude was to “do spirals.” The aircraft then continued a tight descending right turn, and the descent rate and airspeed rapidly increased to near the aircraft’s maneuvering limitations for both bank angle and airspeed. As the aircraft rolled out of the right turn and near a wings-level attitude, three of the battens connecting the left-wing fabric to the wing structure released at the trailing edge. The left wing subsequently began to flutter, and the aircraft rapidly rolled left and entered a spiral dive, from which the pilot was unable to recover before impact with terrain. A Service Instruction issued by the aircraft manufacturer listed three different factors that can cause the hinged batten to unload: 1) damage to the latch from incorrect loading of the fitting, 2) overtension of the batten within the pocket, and 3) operation outside the placarded limitation of the aircraft. While the investigation was not able to determine the state of battens before the accident, a performance study determined that the aircraft banked near its maximum recommended bank angle of 60° and near its maximum maneuvering speed of 73 kts in a right turn during the descent. The battens that separated during the flight were not recovered and therefore could not be examined. Postaccident examinations of the airframe and engine revealed no additional evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. The parachute pin was removed and the parachute was partially deployed. It is likely that the parachute was deployed without enough altitude remaining to fully open and arrest the descent. Ethanol was detected at low levels in the flight instructor’s liver and muscle tissue specimens collected during a postmortem examination. Some or all of the small amounts of detected ethanol may have been from postmortem production, and it is unlikely that ethanol effects contributed to the crash.
HISTORY OF FLIGHTOn November 5, 2022, about 0811 Hawaii-Aleutian standard time, an Airborne Windsports Edge XT-912-L weight-shift-control light sport aircraft, N444EZ, was substantially damaged when it was involved in an accident near Mokuleia, Hawaii. The flight instructor and initial/introductory flight training student were fatally injured. The aircraft was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. According to the operator, Paradise Air Hang Gliding, the flight was a discovery flight lesson and should have lasted about 30 minutes. When the aircraft did not return, another pilot from the operator went to look for the aircraft, and he eventually spotted the wreckage about 2 miles west of the airport. A witness close to the accident site stated that the engine was running, and the aircraft descended in a nose-low attitude until impact. According to ADS-B flight track data and video from a Go-Pro camera recovered from the aircraft wreckage, the aircraft taxied onto the runway for takeoff from Dillingham Airfield (HDH) about 0739. The aircraft flew east of the airport, maneuvering at varying altitudes and making a few 360° turns before turning back to the west. The aircraft flew along the coast towards Ka’ena Point, then made a left climbing turn toward HDH. The aircraft reached a maximum altitude of 5,670 ft mean sea level (msl), then descended to an altitude of 1,200 ft, and then climbed to 2,700 ft. The airplane completed a left 360° and continued to climb. After a second left turn the aircraft began a descent from 2,700 ft (see Figures 1 and 2). As the aircraft entered a right turn at 2,100 ft, the flight instructor told the student another way for them to lose altitude was to “do spirals.” The aircraft then entered a tight descending right turn, rolling to near the recommended limit of 60° and increasing airspeed to near the maneuvering limit of 73 kts. As the aircraft rolled out of the right turn to a near wings-level attitude, three battens connecting the wing fabric to the wing structure released at the trailing edge of the left wing (see Figure 3). The left wing subsequently began to flutter, and the aircraft rapidly rolled left and entered an uncontrolled descending spiral dive. The last track data was observed at 0810, as the aircraft descended through 700 ft msl, at 20 knots. Figure 1. ADS-B flight track for N444EZ, which depicts both outbound and inbound flight tracks. Figure 2. Overhead view of the ADS-B flight track which depicts the last portion of the flight. Figure 3. Sequence of four images from the GoPro camera that captured the batten end fittings release. PERSONNEL INFORMATIONThe flight instructor’s total flight experience was provided by the operator. His pilot logbook was not located. AIRCRAFT INFORMATIONThe aircraft was owned by the flight instructor and operated by Paradise Air Hang Gliding. The operator performed most of the airplane’s maintenance, including the annual and 100-hour inspections. METEOROLOGICAL INFORMATIONA Global Data Assimilation System (GDAS) sounding showed average winds in the area of the accident were equal or greater to 14 knots at or below 5,000 ft. AIRPORT INFORMATIONThe aircraft was owned by the flight instructor and operated by Paradise Air Hang Gliding. The operator performed most of the airplane’s maintenance, including the annual and 100-hour inspections. WRECKAGE AND IMPACT INFORMATIONPostaccident examination of the fuselage revealed it was intact and impact damaged. Flight control continuity was confirmed from the control inputs to the control surfaces. The wing mast was impact damaged; the mast safety cable remained attached. The safety pin was removed from the parachute and it was partially deployed. The battens that separated during the flight were not recovered and therefore could not be examined. The engine remained attached to the airframe. The carburetors were separated from the engine and impact damaged. The fuel tank was breached and empty. All three propeller blades remained attached to the hub; the outboard portions of all the blades were impact separated. ADDITIONAL INFORMATIONThe manufacturer issued AirBorne Service Instruction SB-019, Issue 1, dated January 9, 2015. The instruction states there are several factors that can cause the hinged batten fittings to unload. 1. Damage to the latch from incorrect unloading of the fitting. 2. Over tension of the batten within the pocket. 3. Operation outside the placarded limitation of the aircraft. The Aircraft Operating Instructions advise not to exceed 60°. Additionally, the maneuvering speed, Va, for the aircraft with the XR-S wing is listed as 73 kts. FLIGHT RECORDERSThe operator had installed a GoPro HERO9 digital camera mounted on the right wing pointing toward the pilot and passenger. MEDICAL AND PATHOLOGICAL INFORMATIONThe Department of the Medical Examiner, City and County of Honolulu, performed the autopsy of the pilot. According to the autopsy report, the pilot’s cause of death was massive blunt force trauma, and the manner of death was accident. The Federal Aviation Administration (FAA) Forensic Sciences Laboratory performed toxicological testing of the postmortem tissue of the pilot. Ethanol was detected in liver tissue and muscle at 0.012 g/hg and 0.024 g/hg, respectively. Ethanol is a type of alcohol. It is the intoxicating alcohol in beer, wine, and liquor, and, if consumed, can impair judgment, psychomotor performance, cognition, and vigilance. FAA regulation imposes strict limits on flying after consuming ethanol, including prohibiting pilots from flying with a blood ethanol level of 0.04 g/dL or greater. Alcohol consumption is not the only possible source of ethanol in postmortem specimens. Ethanol can sometimes be produced by microbes in a person’s body after death. Postmortem ethanol production is made more likely by extensive traumatic injury. TESTS AND RESEARCHThe National Transportaiton Safety Board conducted a performance study for this accident. The study included a review of ADS-B and GoPro video data. The data revealed the aircraft began a steep descending turn near the end of flight. The aircraft rapidly gained speed to near its Va while in a bank near its maximum recommended bank angle of 60°. For about 10 seconds of the right turn the aircraft was near the maximum recommended bank angle and Va. Shortly after, three left batten hinges released, causing the left wing to flutter before the aircraft eventually entered a left spiral dive.
Structural failure of the wing for undetermined reasons, which resulted in a loss of control.
Source: NTSB Aviation Accident Database
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