California

Shortly after takeoff from Chino Airport runway 21, while climbing, the twin engine airplane rolled to the left, descended to the ground and crashed in a grassy area, bursting into flames. Both occupants were fatally injured. The airplane was operated on behalf of the Yanks Air Museum.

The pilot departed Stockton Airport on a solo flight to Chino. On a standard approach in rainy conditions, the airplane suffered two altitude deviations which the pilot attributed to a problem with the autopilot. Towards the end of the flight, the airplane descended past the Minimum Vectoring Altitude (MVA) of 7,400 feet and was issued an altitude alert by the controller, but there was no response from the pilot. The airplane entered an uncontrolled descent with a rate of about 10'000 feet per minute until it crashed in mountainous terrain. The airplane was destroyed by impact forces and the pilot was killed.

On final approach to Truckee-Tahoe Airport runway 20 in marginal weather conditions, it is believed that the pilot initiated a go around procedure. While climbing to an altitude of 7,200 feet, control was lost. The airplane entered a dive and crashed in a snow covered forest located near the airport, bursting into flames. Both occupants, Liron and Naomi Petrushka, were killed. At the time of the accident, visibility was limited due to snow showers.

On approach to Temecula-French Airport Runway 36 at night, the crew encountered foggy conditions. Due to poor visibility, the crew initiated a go around then made a right hand turn and followed a circuit for a second attempt to land. On short final, at a speed of approximately 130 knots, the airplane impacted the ground and crashed short of runway, bursting into flames. The airplane was totally destroyed and all six occupants were killed.

The airplane departed Santa Rosa-Sonoma County Airport on a ferry flight to Honolulu, carrying two pilots. It crashed in unknown circumstances into the Pacific Ocean some 54 km west of Half Moon Bay. No trace of the aircraft or the crew was found.

The airplane was engaged in a mission on behalf of the US Navy (callsign Fenix 01) when it crashed in unknown circumstances into the sea about a mile southwest off San Clemente Island NAS. Few debris were found floating on water and all three crew members were killed.

Shortly after taking off, the pilot was instructed to change from the airport tower frequency to the departure control frequency. Numerous radio transmissions followed between tower personnel and the pilot that indicated the airplane’s radio was operating normally on the tower frequency, but the pilot could not change frequencies to departure control as directed. The pilot subsequently requested and received approval to return to the departure airport. During the flight back to the airport, the pilot made radio transmissions that indicated he continued to troubleshoot the radio problems. The airplane’s flight track showed the pilot flew directly toward the runway aimpoint about 1,000 ft from, and perpendicular to, the runway during the left base turn to final and allowed the airplane to descend as low as 200 ft pressure altitude (PA). The pilot then made a right turn about .5 miles from the runway followed by a left turn towards the runway. A pilot witness near the accident location observed the airplane maneuvering and predicted the airplane was going to stall. The airplane’s airspeed decreased to about 53 knots (kts) during the left turn and video showed the airplane’s bank angle increased before the airplane aerodynamically stalled and impacted terrain. Post accident examination of the airframe, engines, and review of recorded engine monitoring data revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. Toxicology testing showed the pilot had diphenhydramine, a sedating antihistamine, in his liver and muscle tissue. While therapeutic levels could not be determined, side effects such as diminished psychomotor performance from his use of diphenhydramine were not evident from operational evidence. Thus, the effects of the pilot’s use of diphenhydramine was not a factor in this accident. The accident is consistent with the pilot becoming distracted by the reported non-critical radio anomaly and turning base leg of the traffic pattern too early during his return to the airport. The pilot then failed to maintain adequate airspeed and proper bank angle while maneuvering from base leg to final approach, resulting in an aerodynamic stall and impact with terrain.

The flight crew was supporting a United States Navy (USN) training mission and ended the flight early due to icing conditions. The flight crew calculated a landing reference speed (Vref) of 140 knots (kts) indicated airspeed (KIAS) and landing distance required of 4,200 ft for a wet runway and a flap setting of 20°. Due to underwing-mounted external storage, the landing flaps were limited to a maximum extension of 20°. The flight crew configured the airplane with 20° flaps and reported that the airplane touched down at 140 kts. Although the runway was 8,001 ft long, an arresting cable was located 1,701 ft from the runway threshold, resulting in a runway distance available of about 6,300 ft. After landing, the second in command (SIC) reported that the pilot-in-command (PIC) deployed the spoilers and brakes, then announced that the airplane was not slowing down. The PIC stated that the airplane did not decelerate normally, that the brake anti-skid system was active, and that the airplane seemed to be hydroplaning. He cycled the brakes, which had no effect.The airplane subsequently overran the departure end of the runway, breached an ocean sea wall and came to rest in a nose-down attitude on a sandbar. The airport weather observation system recorded that 0.06 inches of liquid equivalent precipitation fell between 18 and 9 minutes before the accident. In the 4 hours before the accident, the airport received 0.31 inches of liquid equivalent precipitation. A landing performance study conducted by the airplane manufacturer modeled a variety of landing scenarios considered during the investigation. The modeling used factual information provided by the investigation, including ADS-B data, as well as manufacturer-provided airplane performance data specific to the airplane. The study considered the effect on landing distance of both a wet and dry runway, a contaminated runway, both full and intermittent hydroplaning, a localized tailwind (which was not present in the weather data), and an inboard brake failure. The study showed that the most likely scenario, based on the available data, was that the airplane touched down with a ground speed well in excess of the 140 kts Vref speed reported by the crew, and that subsequent to the touchdown encountered full hydroplaning at speeds above 104 kts. The airplane sat overnight on the sandbar and was submerged in saltwater before the airplane was recovered. As a result, the airplane’s braking system could not be functionally tested. However, the physical evidence from the brakes as found post accident, combined with the results of the landing distance modeling, did not indicate that a brake failure occurred. Similarly, ADS-B data did not support the presence of a localized tailwind when such a landing was modeled in the study. Thus, it’s likely that the flight crew landed too fast and then encountered hydroplaning during the landing roll as a result of a recent heavy rain shower, which diminished the calculated stopping distance.

The pilot of the single-engine airplane was operating in the airport traffic pattern and had been making position reports on the airport’s common traffic advisory frequency (CTAF). The pilot of the multi-engine airplane made an initial radio call on the CTAF 10 miles from the airport, announcing his intention to perform a straight-in approach for landing. Both pilots continued to make appropriate position reports, but did not communicate with each other until the multi engine airplane was about one mile from the airport and the single-engine airplane had turned onto the base leg of the traffic pattern for landing. Realizing that the multi-engine airplane was converging upon him, the pilot of the single-engine airplane announced a go-around, and the airplanes collided on final approach for the runway about 150 ft above ground level (agl). Examination of the airplanes revealed no evidence of mechanical malfunctions or anomalies that would have precluded normal operation. The multi-engine airplane’s wing flaps and landing gear were both retracted at the accident site, consistent with the pilot’s failure to configure the airplane for landing, and flight track information indicated that the pilot maintained a ground speed of about 180 knots throughout the approach until the collision occurred, which may have reduced the time available for him to see and avoid the single engine airplane. The toxicology report for the pilot of the single-engine airplane revealed THC, metabolites for THC, metabolites for cocaine, and ketamine; the low amounts of each drug were not considered causal to the accident. The toxicology report for the multi-engine airplane pilot revealed THC, and metabolites of THC; the low amounts of each drug were not considered causal to the accident.

The pilots were performing skydiving flights while the right-seated pilot was training the left-seated pilot on the operation. The pilots completed six flights without incident and completed the drop of the skydivers on the accident flight normally. The right-seated pilot could not completely recollect the minutes leading up to the accident due to his injuries. He did recall that airplane was descending as expected with the power at idle. The recorded ADS-B data revealed that after turning onto final approach, the airplane then completed a right 360° turn presumably because the altitude was too high. The right-seated pilot attempted to increase the power by slightly nudging the throttle forward and thought the engine power did not increase as expected. A performance study revealed that in the last 70 seconds of recorded data, the airplane underwent a series of speed and thrust oscillations consistent with a pilot increasing and then decreasing the power lever. The right seat pilot recalls aiming for an open dirt field and observing a berm in the immediate flight path. In an effort to avoid the berm, he maneuvered the airplane into a right turn. The airplane landed short of the runway, resulting in a collision with the berm. The engine was producing power at the time of impact. Postaccident examination of the airplane revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The right-seated pilot was in the process of training the left-seated pilot and stated that he took over the controls during the final approach. It is unknown when he took over the controls, so it is unknown which pilot was at the controls during the speed oscillations. The right-seated pilot likely took over the controls too late and the airplane impacted the terrain. The left-seated pilot’s ability to hear the changes in engine power might have been hindered because she was listening to music through her headset at an elevated decibel level. The airplane was modified by a Supplemental Type Certificate that replaces the original Pratt & Whitney PT-6 turbine engine with a Honeywell TPE331 turbine engine. The TPE331 engine’s characteristics are such that if the airplane is on final approach with the power near idle, the throttle sensitivity (change in thrust per unit of power lever movement) increases around the transition between the propellergoverning and underspeed-governing modes of the engine, which corresponds to a zero-thrust condition. Near this transition point, small movements of the power lever (about ¼ to ½ inch of deflection) can result in relatively large thrust changes that can surprise pilots inexperienced with this behavior and result in pilot-induced oscillations (PIO). Given the thrust oscillations observed shortly before the end of the ADS-B data, it is likely that the left-seated pilot was at the controls and experienced such a PIO on a short final approach to land.