N8448J

HISTORY OF FLIGHT***This report was modified on December 15, 2020. Please see the docket for this accident to view the original report.***

On November 17, 2018, about 1835 eastern standard time, an experimental amateur-built Lancair Legacy RG, N8448J, was substantially damaged when it was involved in an accident in Gainesville, Georgia. The private pilot owner of the airplane was fatally injured, and the flight instructor was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.

The accident occurred during the third flight of the day. The first flight was local and flown solo by the flight instructor; he performed three takeoffs and landings at Lee Gilmer Memorial Airport (GVL), Gainesville, Georgia. Both pilots flew the airplane on the second flight from GVL to Charleston Executive Airport (JZI), Charleston, South Carolina. The accident occurred on the third fight, which departed JZI about 1728, and arrived in the vicinity of GVL at 1835, about 1 hour after sunset.

As the airplane approached GVL, the flight instructor requested clearance from the air traffic controller for a practice GPS approach to runway 23, which the controller approved. Runway 23 was at an elevation of 1,276.9 ft mean sea level (msl) and equipped with a two-light precision approach path indicator (PAPI), located on the left side.

A witness in an airplane waiting to takeoff from runway 23 saw the accident airplane approach the runway. He indicated that he saw the landing lights, which "became dim and they appeared to roll 180 degrees" before the accident.

The flight instructor recalled that the pilot was flying the airplane on the approach when the airplane suddenly became inverted. He did not recall any further details.

According to flight data recorded by the airplane's primary flight display (PFD), while at an altitude of 3,500 ft msl with the autopilot engaged, the airplane arrived at the initial approach fix from the southeast and turned left onto the inbound course. About 12 seconds before the airplane reached the final approach fix, the autopilot vertical mode changed from altitude hold mode to glidepath mode. Just after the airplane passed the final approach fix at an indicated airspeed of 165 knots, the flaps were extended to 17°. The pitch attitude then changed from 0° to about 9°nose down, the indicated airspeed increased from 165 to 177 knots, and the airplane descended below the glidepath. The autopilot elevator servo began applying torque to the elevator in the nose-up direction, and the airplane then stabilized slightly above the glidepath for about 16 seconds. The pitch attitude then increased slightly, and the airplane drifted above the glidepath, as the autopilot began applying torque to the elevator servo in the nose-down direction. About 2.6 nautical miles from the runway at an altitude of 2,200 ft msl (923 ft above the runway elevation) and an indicated airspeed of 138 knots, the landing gear were lowered and the airplane drifted farther above the glidepath. The elevator servo torque increased, and as a result, the electric pitch trim (controlled by the autopilot, when engaged) increased continuously from a value of 8 units to 67 units in the nose-down direction (which is at or near the full nose down position; it remained at this value until the recording ended), as the elevator servo continued to apply torque in the nose-down direction. The pitch attitude decreased to about 2.5° nose down, however the airplane remained above the glidepath. The course deviation indicator (CDI) increased to nearly the full scale "fly down" indication. The engine power parameter was 42%, where it remained for most of the approach. About 1.6 miles from the runway, at an altitude of 1,900 ft msl (623 ft above the runway) and an indicated airspeed of 127 knots, just as the pitch trim servo reached the value of 67 units, the autopilot was disengaged. About 15 seconds later, the flaps were extended to 40°, remained there for about 5 seconds, and were then fully retracted. As the flaps were retracting, the airplane was descending through the glidepath, the descent rate increased from about 600 ft per minute (fpm) to about 1,200 fpm, and the pitch attitude began to slowly increase from about 2° nose down to 2° nose up. The roll attitude varied between 8° left wing down and 3° right wing down after the flaps were retracted. The engine power was reduced to 32% about 4 seconds before the recorded data ended. The last recorded data point was captured when the airplane was about 0.3 mile from the runway, on the extended runway centerline, at an altitude of 1,323 ft msl (46 ft above the runway). The indicated airspeed was 110 knots, the descent rate was 1,029 fpm, the wings were level, and the pitch attitude was about 2.5° nose up. The CDI indicated full scale "fly up" indication.

About 0.1 mile from the runway, while on the extended runway centerline, the airplane struck tree tops that were about the same elevation as the runway (the trees were about 50 ft tall and located in a valley), at the edge of a 4-lane divided highway oriented perpendicular to the runway. The airplane descended and impacted terrain and a wooden platform that held the localizer antenna for runway 05, located about 500 ft from the approach end of runway 23.

A review of the PFD flight data for each flight on the day of the accident did not reveal any indications of preflight checks of the elevator trim or autopilot system.

PERSONNEL INFORMATIONExamination of the pilot's logbook revealed the last entry was dated August 21, 2017, before he purchased the accident airplane. The logbook contained complex and high-performance endorsements. His experience in the accident airplane was documented in an airplane usage logbook and an email printout; both were found in the wreckage. The records indicated that he flew with another pilot for at least 92 of the 96 flight hours in the accident airplane but did not indicate the nature of those flights or details to document currency.

AIRCRAFT INFORMATIONThe two-seat, low-wing, composite, retractable tricycle design airplane was built in 2015. It was equipped with an autopilot and an electric pitch, roll, and yaw trim system.

According to a Lancair Owners and Builders Organization Lancair Legacy training manual, deployment of the flaps causes the nose to pitch down, requiring up-elevator trim. It further states that "flight without an operational pitch trim system is difficult."

According to the Garmin G3X Pilot's Guide, a section titled "Overpowering Autopilot Servos" reads:

In the context of this discussion, "overpowering" refers to any pressure or force applied to the pitch controls when the autopilot is engaged. A small amount of pressure or force on the pitch controls can cause the autopilot automatic trim to run to an out-of-trim condition. Therefore, any application of pressure or force to the controls should be avoided when the autopilot is engaged.

Overpowering the autopilot during flight will cause the autopilot's automatic trim to run, resulting in an out-of-trim condition or cause the trim to hit the stop if the action is prolonged. In this case, larger than anticipated control forces are required after the autopilot is disengaged.

The pilot's guide also notes that in addition to being disengaged manually, the autopilot can also disengage automatically in the event of a system failure, invalid sensor data, or the inability to compute default autopilot modes. The guide did not indicate that the autopilot would disengage automatically due to excessive control or trim forces. No failures were noted in the recorded data, however the guide did not provide details on which failure conditions are captured by the recording system.

METEOROLOGICAL INFORMATIONAccording to U.S. Naval Observatory records, the sun had set at 1730, civil twilight ended at 1757, and the moon was in the waxing gibbous phase with 70% of the moons disk illuminated.

AIRPORT INFORMATIONThe two-seat, low-wing, composite, retractable tricycle design airplane was built in 2015. It was equipped with an autopilot and an electric pitch, roll, and yaw trim system.

According to a Lancair Owners and Builders Organization Lancair Legacy training manual, deployment of the flaps causes the nose to pitch down, requiring up-elevator trim. It further states that "flight without an operational pitch trim system is difficult."

According to the Garmin G3X Pilot's Guide, a section titled "Overpowering Autopilot Servos" reads:

In the context of this discussion, "overpowering" refers to any pressure or force applied to the pitch controls when the autopilot is engaged. A small amount of pressure or force on the pitch controls can cause the autopilot automatic trim to run to an out-of-trim condition. Therefore, any application of pressure or force to the controls should be avoided when the autopilot is engaged.

Overpowering the autopilot during flight will cause the autopilot's automatic trim to run, resulting in an out-of-trim condition or cause the trim to hit the stop if the action is prolonged. In this case, larger than anticipated control forces are required after the autopilot is disengaged.

The pilot's guide also notes that in addition to being disengaged manually, the autopilot can also disengage automatically in the event of a system failure, invalid sensor data, or the inability to compute default autopilot modes. The guide did not indicate that the autopilot would disengage automatically due to excessive control or trim forces. No failures were noted in the recorded data, however the guide did not provide details on which failure conditions are captured by the recording system.

WRECKAGE AND IMPACT INFORMATIONA 175-ft-long debris path extended from the localizer platform along a heading of 215° magnetic to the main wreckage which came to rest upright, on a heading of about 225°.

Additional debris...