CESSNA 182 — Reliance, TN

What happened

The instrument-rated private pilot departed on an instrument flight rules (IFR) flight and climbed to 9,000 ft mean sea level (msl) on a southeast heading. Radar data indicated that for about the first 2 hours and 30 minutes, the airplane maintained a relatively straight course. Twice the pilot requested air traffic control (ATC) provide radar vectors around weather, confirming with one controller that the airplane was equipped with on-board weather observation capability. During cruise flight, while flying at an airspeed above the airplane’s published maneuvering speed in an area with a valid Convective SIGMET, the airplane encountered the leading edge of precipitation and building cumuliform clouds in convective updrafts. This weather system was associated with a line of forecast thunderstorms and other pilots had reported the presence of severe to extreme turbulence while flying in the vicinity of it. The accident airplane’s heading and altitude changed several times during the final portion of the flight, and these deviations were not instructed by the controller or announced by the pilot.

Following a second right turn the controller commented to the pilot, “it looks like you are in a little bit of a descent in a turn is everything alright?” The pilot did not reply to that communication and radar contact with the airplane was lost. A radar performance study indicated that when the airplane was last observed by radar, while flying at an altitude of about 8,850 ft msl, it was operating at a calibrated airspeed of 134 knots, which was 35 knots greater than the published maneuvering speed. Although the radar data did not capture the final descent, the airplane likely began descending after encountering severe to extreme turbulence. During that descent, the airplane’s airspeed which was already well above the published maneuvering speed likely increased and an in-flight break-up occurred, separating both wings and a majority of the right horizontal stabilizer and right elevator from the fuselage.

The postaccident examination of the airframe revealed that all fracture surfaces displayed features consistent with overload failure with no evidence of preexisting cracking. The examination of the engine revealed no evidence of any preimpact failures or malfunctions. The airplane was equipped with a Ballistic Recovery Systems (BRS), and that system’s parachute and riser (lanyard) were not recovered following the accident.

Examination of the BRS airframe system components revealed that the fire pin actuator was inside the rocket cone with the activation cable still attached, which was consistent with normal activation. Evidence indicated that the forward straps that connected to each front main spar, and the rear straps that were connected to the left and right attach plates on the rear bulkhead, remained connected to their respective bolts at the 3-point shackle. The 3-point shackle, which had separate attach points (bolts) for the forward and aft straps, and for the riser (lanyard) of the parachute, was located within the main wreckage. However, the riser for the airframe parachute was not attached to the 3-point shackle. The 3-point shackle bolt for the parachute riser was not visibly deformed. The other two bolts of the 3-point shackle that secured the forward and aft straps also did not exhibit any visible damage. Examination of a portion of the rear harness revealed that the shock absorption stitching pattern was not peeled/torn, indicating that there was no force applied to the rear harness at the 3-point shackle level.

Based on this information, it is likely that the pilot activated the airframe parachute at some point during the accident sequence, the parachute bag properly deployed from its canister, and the forward harness straps opened from their stowed position; however, with the parachute riser not attached to the 3-point shackle, the BRS parachute would have been useless. Because the parachute and riser were not located, it could not be determined why the parachute riser, which last had maintenance performed nearly 6 years earlier, was not attached to the 3-point shackle.

The pilot’s logbook was not located; therefore, the date of his last flight review and his instrument currency could not be determined. About 7 months before the accident, he last reported having accumulated 341 total hours of flight experience, of which 265 hours were in the accident airplane make and model.

Toxicological testing results were positive for amphetamine, quetiapine, hydroxychloroquine, tadalafil, acetaminophen and ethanol. The FAA considers amphetamine and quetiapine as “Do Not Issue/Do Not Fly” medications. Whether the effects of the pilot’s use of amphetamine, quetiapine, hydroxychloroquine, or any associated underlying conditions contributed to the accident or affected his decision making could not be determined. Some or all of the small amount of detected ethanol could have been the result of postmortem production, and it is unlikely that ethanol effects contributed to the accident.

In summary, the relatively low-time instrument pilot, who was flying while using multiple unapproved medications, flew into an area of a forecast convective weather that included precipitation and building cumuliform clouds in convective updrafts. These conditions were associated with a line of thunderstorms and severe to extreme turbulence, the latter of which by definition can render an airplane practically impossible to control. While flying well above the published maneuvering speed for the airplane’s weight, the airplane likely began descending with a corresponding airspeed increase, followed by an abrupt or full-control input that resulted in the in-flight breakup.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.