N81DJArion Aircraft LIGHTNING LS-1 · 2009

On April 9, 2020, about 2100 eastern daylight time, an experimental, amateur-built Arion Aircraft LLC Lightning LS-1 airplane, N81DJ, was destroyed when it was involved in an accident near Mount Pleasant Regional Airport-Faison Field (LRO), Mount Pleasant, South Carolina. The pilot and the flight instructor were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.

The student pilot, who had recently purchased the airplane, and the flight instructor departed Myrtle Beach International Airport (MYR), Myrtle Beach, South Carolina, about 2011 and flew to LRO, about 65 nautical miles away. A review of Federal Aviation Administration (FAA) air traffic control (ATC) communications and Automatic Dependent Surveillance-Broadcast data revealed that ATC cleared the pilot for takeoff on Runway 36 and instructed him to fly runway heading. The pilot acknowledged by reading back the clearance correctly.

At 2013, the controller handed off the flight to departure control and the pilot reported climbing out of 600 ft mean sea level (MSL). The airplane was radar identified by the controller who subsequently issued a left turn on course and instructed the pilot to maintain visual flight rules (VFR), which was acknowledged. At 2045, ATC instructed the pilot to maintain VFR at 3,000 ft. While en route at 3,000 ft, the pilot requested a descent into LRO at 2051, which ATC acknowledged, and authorized a VFR descent at the pilot’s discretion.

The pilot advised the controller that they would be executing a touch-and-go at LRO before flying back to MYR. The controller responded by telling the pilot to remain on their beacon code. He then issued contact information for their subsequent departure and climb out of LRO, then authorized a change to the LRO common traffic advisory frequency. This was the last communication between the controller and the pilot. No additional communications were received.

ADS-B data showed the airplane enter a descending left turn on final approach to LRO runway 17; the last ADS-B-recorded position showed the airplane at an altitude of 525 ft on final approach to the runway. About 8 minutes later, ATC was notified by local law enforcement that a witness had reported that hearing an aircraft engine before the engine sound stopped near the airport. The map in figure 1 shows the airplane's approach into LRO. The ADS-B track is in blue, and an inset depicting the accident site in relation to the runway and airport property is marked. The departure end of the runway was surrounded by 75 to 100 ft tall trees about 1,700 ft south-southeast of the departure end of the runway. Beyond the trees were residential areas and a highway, followed by a water inlet and the Atlantic Ocean which was about 2 miles south-southeast of the airport.

Figure 1 - Accident airplane’s track represented by a blue line with altitude, heading and speed annotated. The inset shows expanded view of accident site in relation to the runway and airport property.

A line service employee at MYR reported that the day before the accident flight, the pilot and flight instructor completed a flight during the day. When they arrived back at MYR, they requested a fuel top off. The employee put 6.2 gallons of aviation fuel on board, which topped off both fuel tanks. No additional flights were flown until the accident flight the following evening. An additional witness stated that on the evening of the accident, the pilot and flight instructor informed her that they would be conducting a night flight and they would return late. She reported that both pilots appeared to be in good spirits as they left the building and that the airplane’s departure from MYR appeared “normal.”

According to the US Naval Observatory Astronomical Applications department, dark night conditions existed at the time of the accident. Sunset occurred at 1946 and the end of civil twilight was 2011. The moon was below the horizon at the time of the accident, and moonrise occurred about 1 hour after the accident at 2150.

A FAA inspector examined the wreckage at the accident site and reported that the airplane impacted heavily wooded flat terrain about 1/2-mile south of the departure end of runway 17. The airplane struck the tops of 75 to 100 ft-tall trees bordering the airport perimeter; several broken tree limbs, branches, and small pieces of fiberglass and plexiglass were found near the mature trees immediately adjacent to the airport perimeter security fence. The debris path beyond the initial impact point was about 250 ft long and oriented toward the south-southeast.

The airplane was heavily fragmented. Both wings were separated and were broken in multiple pieces; the main wing spar was separated from the wings in its entirety. All primary flight control surfaces were separated from their respective locations and found along the wreckage path. The engine separated from the firewall but remained attached to the lower engine mounts and was partially covered by the engine cowling. The entire airframe was fragmented into small pieces.

Flight control continuity was established through overloaded cable ends and fractured torque tubes. The rudder and elevator were fractured off at their respective mounts. The airframe could not be fully inspected due to severe fragmentation.

A portion of the fixed pitch propeller remained attached to the propeller flange and engine. The spinner was crushed in a rotational pattern, and one propeller blade was fractured and separated near its root. Eighteen inches of the opposing blade remained attached to the flange and was cleanly broken.

The engine’s top spark plugs were removed and showed normal wear; several of the top spark plugs were fractured. The rear accessory case was impact damaged which initially prevented crankshaft rotation; the coil assembly was subsequently removed so the engine crankshaft rotated freely. Compression was established on all cylinders and a lighted borescope was used to exam the cylinders, valves, and pistons. Carbon deposits were noted on the piston heads, but no additional anomalies were discovered. The carburetor which was fractured off. The engine was disassembled, and no anomalies were noted. Continuity of the fuel system could not be confirmed. Both fuel tanks were breached, and the fuel selector valve was separated from the fuselage. The valve handle was found in the left tank position. No anomalies were discovered with the airframe or engine that would have precluded normal operation.

Student Pilot

According to the autopsy report requested by the Charleston County Coroner and performed by the Department of Pathology and Medicine, Medical University of South Carolina, the cause of death for the student pilot was multiple blunt force injuries and the manner of death was accident. Except for focal atherosclerosis of 70% in the left anterior descending artery, no significant natural disease was identified by the pathologist.

Flight Instructor

According to the autopsy report requested by the Charleston County Coroner and performed by the Department of Pathology and Medicine, Medical University of South Carolina, the cause of death for the flight instructor was multiple blunt force injuries and the manner of death was accident. Except for focal atherosclerosis of 70% in the left anterior descending artery, no significant natural disease was identified by the pathologist.

Toxicology testing for both the student pilot and the flight instructor did not detect any medications that would be considered impairing or sedating.

According to the FAA's General Aviation Joint Steering Committee, a pilot's sight, supported by other senses, allows a pilot to maintain orientation while flying. However, when visibility is restricted (that is, no visual reference to the horizon or surface detected), the body's supporting senses can conflict with what is seen. When this spatial disorientation occurs, sensory conflicts and optical illusions often make it difficult for a pilot to tell which way is up. The FAA Airplane Flying Handbook (FAA-H-8083-3B) described some hazards associated with flying when visual references, such as the ground or horizon, are obscured:

The vestibular sense (motion sensing by the inner ear) in particular tends to confuse the pilot. Because of inertia, the sensory areas of the inner ear cannot detect slight changes in the attitude of the airplane, nor can they accurately sense attitude changes that occur at a uniform rate over a period of time. On the other hand, false sensations are often generated; leading the pilot to believe the attitude of the airplane has changed when in fact, it has not. These false sensations result in the pilot experiencing spatial disorientation.

The FAA publication Medical Facts for Pilots (AM-400-03/1) described several vestibular illusions associated with the operation of aircraft in low visibility conditions. Somatogravic illusions, those involving the utricle and saccule of the vestibular system, were generally placed into one of three categories, one of which was "the head-up illusion." According to the text, the head-up illusion involves a forward linear acceleration, such as takeoff, where the pilot perceives that the nose of the aircraft is pitching up. The pilot's response to this illusion would be to push the control yoke forward to pitch the nose of the aircraft down. "A night takeoff from a well-light airport into a totally dark sky (black hole) or a catapult takeoff from an aircraft carrier can also lead to this illusion and could result in a crash."