California

The pilot reported that, while holding short of the runway, he set the parking brake while waiting for his takeoff clearance. Upon receiving takeoff clearance, he reached down to the parking brake handle and, "quickly pushed the parking brakes back in"; however, he did not visually verify that he disengaged the parking brake. During the takeoff roll, he noticed that the airplane was not accelerating beyond about 70 knots and decided to abort the takeoff. The airplane subsequently veered to the left, exited the departure end of the runway, and impacted an airport perimeter fence. The pilot reported that he must have not fully disengaged the parking brake before takeoff and that there were no mechanical issues with the airplane that would have precluded normal operation. Postaccident examination of the airplane revealed that the parking brake handle was partially extended, which likely resulted in the airplane’s decreased acceleration during the takeoff roll.

The crew was conducting an on-demand charter flight with eight passengers onboard. As the flight crew taxied the airplane to the departure runway, the copilot called air traffic control using his mobile phone to obtain the departure clearance and release. According to the pilot, while continuing to taxi, he stopped the airplane short of the runway where he performed a rudder bias check (the last item in the taxi checklist) and applied the parking brake without verbalizing the parking brake or rudder bias actions because the copilot was on the phone. After the pilot lined up on the runway and shortly before takeoff, the flight crew discussed and corrected a NO TAKEOFF annunciation for an unsafe trim setting. After the copilot confirmed takeoff power was set, he stated that the airplane was barely moving then said that something was not right, to which the pilot replied the airplane was rolling and to call the airspeeds. About 16 seconds later, the pilot indicated that the airplane was using more runway than he expected then made callouts for takeoff-decision speed and rotation speed. The pilot stated that he pulled the yoke back twice, but the airplane did not lift off. Shortly after, the pilot applied full thrust reversers and maximum braking, then the airplane exited the departure end of the runway, impacted a ditch, and came to rest 1,990 ft beyond the departure end of the runway. The airplane was destroyed by a postcrash fire, and the crew and passengers were not injured.

The pilot began the takeoff roll in visual meteorological conditions. The airplane was airborne about 1,300 ft down the runway, which was about 75% of the normal ground roll distance for the airplane’s weight and the takeoff environment. About 2 seconds after rotation, the airplane rolled left. Three seconds later, the airplane had reached an altitude of about 80 ft above ground level and was in a 90° left bank. The nose then dropped as the airplane rolled inverted and struck the ground in a right-wing-low, nose-down attitude. The airplane was destroyed. Postaccident examination did not reveal any anomalies with the airframe or engines that would have precluded normal operation. The landing gear, flap, and trim positions were appropriate for takeoff and flight control continuity was confirmed. The symmetry of damage between both propeller assemblies indicated that both engines were producing equal and high amounts of power at impact. The autopsy revealed no natural disease was present that could pose a significant hazard to flight safety. Review of surveillance video footage from before the accident revealed that the elevator was in the almost full nose-up (or trailing edge up) position during the taxi and the beginning of the takeoff roll. Surveillance footage also showed that the pilot did not perform a preflight inspection of the airplane or control check before the accident flight. According to the pilot’s friend who was also in the hangar, as the accident pilot was pushing the airplane back into his hangar on the night before the accident, he manipulated and locked the elevator in the trailing edge up position to clear an obstacle in the hangar. However, no evidence of an installed elevator control lock was found in the cabin after the accident. The loss of control during takeoff was likely due to the pilot’s use of an unapproved elevator control lock device. Despite video evidence of the elevator locked in the trailing edge up position before the accident, an examination revealed no evidence of an installed control lock in the cabin. Therefore, during the night before the accident, the pilot likely placed an unapproved object between the elevator balance weight and the trailing edge of the horizontal stabilizer to lock the elevator in the trailing edge up position. The loss of control was also due to the pilot’s failure to correctly position the elevator before takeoff. The pilot’s friend at the hangar also reported that the pilot was running about one hour late; the night before, he was trying to troubleshoot an electrical issue in the airplane that caused a circuit breaker to keep tripping, which may have become a distraction to the pilot. The pilot had the opportunity to detect his error in not freeing the elevator both before boarding the airplane and again while in the airplane, either via a control check or detecting an anomalous aft position of the yoke. The pilot directed his attention to the arrival of a motorbike in the hangar alley shortly after he pulled the airplane out of the hangar, which likely distracted the pilot and further delayed his departure. He did not conduct a preflight inspection of the airplane or control check before the accident flight, due either to distraction or time pressure.

The commercial pilot departed for a cross-country, personal flight with no flight plan filed. No evidence was found that the pilot received a preflight weather briefing; therefore, it could not be determined if he checked or received any weather information before or during the accident flight. Visual meteorological conditions existed at the departure airport; however, during the departure climb, the weather transitioned to instrument meteorological conditions (IMC) with precipitation, microburst, and rain showers over the accident area. During the takeoff clearance, the air traffic controller cautioned the pilot about deteriorating weather conditions about 4 miles east of the airport. Radar data showed that, about 5 1/2 minutes after takeoff, the airplane had climbed to about 7,800 ft above ground level before it started a rapid descending right turn and subsequently impacted the ground about 9.6 miles east of the departure airport. Recorded data from the airplane’s Appareo Stratus 2S (portable ADS-B receiver and attitude heading and reference system) revealed that, during the last 15 seconds of the flight, the airplane’s attitude changed erratically with the pitch angle fluctuating between 45° nose-down and 75°nose-up, and the bank angle fluctuating between 170° left and 150° right while descending from 5,500 to 500 ft above ground level, indicative of a loss of airplane control shortly after the airplane entered the clouds. Several witnesses located near the accident site reported seeing the airplane exit the clouds at a high descent rate, followed by airplane parts breaking off. One witness reported that he saw the airplane exit the overcast cloud layer with a nose down pitch of about 60°and remain in that attitude for about 4 to 5 seconds “before initiating a high-speed dive recovery,” at the bottom of which, the airplane began to roll right as the left horizontal stabilizer separated from the airplane, immediately followed by the remaining empennage. He added that the left wing then appeared to shear off near the left engine, followed by the wing igniting. An outdoor home security camera, located about 0.5 mile north-northwest of the accident location, captured the airplane exiting the clouds trailing black smoke and then igniting. Examination of the debris field, airplane component damage patterns, and the fracture surfaces of separated parts revealed that both wings and the one-piece horizontal stabilizer and elevators were separated from the empennage in flight due to overstress, which resulted from excessive air loads. Although the airplane was equipped with an autopilot, the erratic variations in heading and altitude during the last 15 seconds of the flight indicated that the pilot was likely hand-flying the airplane; therefore, he likely induced the excessive air loads while attempting to regain airplane control. Conditions conducive to the development of spatial orientation existed around the time of the in-flight breakup, including restricted visibility and the flight entering IMC. The flight track data was consistent with the known effects of spatial disorientation and a resultant loss of airplane control. Therefore, the pilot likely lost airplane control after inadvertently entering IMC due to spatial disorientation, which resulted in the exceedance of the airplane’s design stress limits and subsequent in-flight breakup. Contributing to accident was the pilot’s improper decision to conduct the flight under visual flight rules despite encountering IMC and continuing the flight when the conditions deteriorated. Toxicology testing on specimens from the pilot detected the presence of delta-9-tetrahydrocanninol (THC) in heart blood, which indicated that the pilot had used marijuana at some point before the flight. Although there is no direct relationship between postmortem blood levels and antemortem effects from THC, it does undergo postmortem redistribution. Therefore, the antemortem THC level was likely lower than detected postmortem level due to postmortem redistribution from use of marijuana days previously, and it is unlikely that the pilot’s use of marijuana contributed to his poor decision-making the day of the accident. The toxicology testing also detected 67 ng/mL of the sedating antihistamine diphenhydramine. Generally, diphenhydramine is expected to cause sedating effects between 25 to 1,120 ng/mL. However, diphenhydramine undergoes postmortem redistribution, and the postmortem heart blood level may increase by about three times. Therefore, the antemortem level of diphenhydramine was likely at or below the lowest level expected to cause significant effects, and thus it is unlikely that the pilot’s use of diphenhydramine contributed to the accident.

The pilot and four passengers were nearing the completion of a cross-county business flight. While maneuvering in the traffic pattern at the destination airport, the controller asked the pilot if he could accept a shorter runway. The pilot said he could not, so he was instructed to enter a holding pattern for sequencing; less than a minute later, the pilot said he could accept the shorter runway. He was instructed to conduct a left 270° turn to enter the traffic pattern. The pilot initiated a left bank turn and then several seconds later the bank increased, and the airplane subsequently entered a steep nose-down descent. The airplane impacted a shopping center parking lot about 1.6 miles from the destination airport. A review of the airplane's flight data revealed that, shortly after entering the left turn, and as the airplane’s bank increased, its airspeed decreased to about 59 knots, which was well below the manufacturer’s published stall speed in any configuration. Postaccident examination of the airframe and engines revealed no anomalies that would have precluded normal operation. It is likely that the pilot failed to maintain airspeed during the turn, which resulted in an exceedance of the aircraft's critical angle of attack and an aerodynamic stall.

The airplane manufacturer was conducting spin flight testing for the installation of a cargo pod when the airplane exhibited aberrant behavior and the testing was halted. The chief design engineer (CDE) was consulted, and, to provide a margin of safety for further flights, a forward center of gravity position was authorized for flaps up and flaps takeoff entries to gain more insight into the airplane's behavior on the previous flight. At the final briefing, before the next flight, the flight crew added spins with flaps in the landing configuration (flaps landing) into the test plan without the CDE's consultation or authorization. According to the pilot flying, after two wings-level, power on, flaps landing spins with left rudder and right aileron, a third spin entry was flown in the same configuration except that the entry was from a 30° left-bank turn. The airplane entered a normal spin, and, at one turn, flight controls were inputted for a normal recovery; however, the airplane settled into a fully developed spin. When recovery attempts failed, the decision was made to deploy the anti-spin parachute. After repeated unsuccessful attempts to deploy the anti-spin parachute, and when the airplane's altitude reached about 500 ft above the briefed minimum bailout altitude, both pilots called for and executed a bailout. The airplane impacted the ground and was destroyed. A postaccident examination of the anti-spin parachute system revealed that half of the connector hook had opened, which allowed the activation pin lanyard for the anti-spin parachute to become disengaged. Based on the airplane's previous aberrant behavior and the conservative parameters that the CDE had previously set, it is not likely that the CDE would have authorized abused spin entries without a prior testing buildup to those entries. Thus, the flight crew made an inappropriate decision to introduce flaps landing entry spin testing, and the failure of the anti-spin parachute contributed to the accident.

The pilot of the twin-engine, turbine-powered airplane reported that, while providing flights for skydivers throughout the day, he had a potential new hire pilot flying with him in the right seat. He added that, on the eighth flight of the day, the new pilot was flying during the approach and "approximately 200 feet south from the threshold of [runway] 15 at approximately 15 feet AGL [above ground level] the bottom violently and unexpectedly dropped out. [He] believe[d] some kind of wind shear caused the aircraft [to] slam onto [the] runway and bounce into the air at a 45 to 60-degree bank angle to the right." The prospective pilot then said, "you got it." The pilot took control of the airplane and initiated a go-around by increasing power, which aggravated the "off runway heading." The right wing contacted the ground, the airplane exited the runway to the right and impacted a fuel truck, and the right wing separated from the airplane. The impact caused the pilot to unintentionally add max power, and the airplane, with only the left engine functioning, ground looped to the right, coming to rest nose down.