WPR24FA309

The pilots departed in separate airplanes (a Nanchang CJ-6A and a Yak 52) as a formation flight from the same airport, with the Yak as the lead airplane and the CJ-6A as the dash 2 (wingman) off the Yak’s right wing. According to the Yak pilot, during the flight the pilots briefed their detachment procedure over the radio because they were bound for separate destinations. The briefed procedure was for them to accelerate from 210 kilometers per hour (kph) to 250 kph, at which time the CJ-6A would pitch up and bank left toward the east while the Yak would continue straight. However, during the detachment, and while the Yak pilot looked away briefly to scan his instruments, the CJ-6A entered a slightly inverted and nose-low position above the Yak and the airplanes collided. The Yak’s propeller blades separated and the pilot subsequently made a forced landing on a nearby road, while the CJ-6A rolled right several times and then impacted the ground. Postaccident examination of the CJ-6A and Yak did not reveal any preimpact mechanical anomalies or malfunctions that would have precluded normal operation. The CJ-6A accident site signatures indicated that the airplane impacted the ground in a wings-level and slightly nose-low attitude as most of the energy was absorbed by the lower engine bay. Paint transfer markings and damage signatures from both airplanes indicated that the airplanes collided when the CJ-6A was inverted and canted slightly right of the Yak’s longitudinal axis. The Yak’s propeller impacted the CJ-6A’s left wing and the Yak’s left wing impacted the CJ-6A’s vertical stabilizer, which resulted in a partial separation of the airfoil. There was insufficient evidence to determine either airplane’s final movements prior to the midair collision. The CJ-6A was not equipped with an ejection seat; however, the pilot had a parachute and may have decided to jump from the airplane since the wreckage indicates that the pilot’s canopy was fully open at impact. However, a witness reported that the airplane was in a roll prior to its collision with terrain, so the pilot may not have been able to initiate a jump. Toxicological testing detected the presence of ethanol in the CJ-6A pilot’s cavity blood and gastric contents. Ethanol was not detected in the pilot’s vitreous fluid, which is the preferred specimen type. The other two tested specimen types also contained n propanol. In the presence of extensive injury, this indicates that the detected ethanol likely was from postmortem sources rather than alcohol consumption. It is unlikely that the CJ-6A pilot was impaired by the effects of ethanol at the time of the accident. The pilots were both part of an association that teaches pilots the fundamentals of formation flight through various clinics. The detachment procedure they used was not in the association’s formation flight manual. In addition, while the Yak pilot reported that they briefed the procedure, there were no recordings to show how thedetachment procedure was communicated and whether there were any interpretation errors. The pilot of the CJ-6A did not exhibit any abnormal behavior over the radio or on the ground prior to departure and the flight was not in an area of adverse weather conditions, so it is unknown why the CJ-6A pilot rolled into a nearly inverted position during the detachment. While the accident was initiated by the CJ-6A pilot’s improper roll during the detachment procedure, the Yak pilot failed to continue monitoring the CJ-6A during a critical time as he turned his attention away from the airplane during the detachment.

On September 22, 2024, at about 1248 Pacific daylight time, a Nanchang CJ-6A airplane, N313YK, and a Yakovlev Yak 52 airplane, N5287, were substantially damaged when they were involved in a midair collision near Lancaster, California. The pilot of the CJ-6A was fatally injured and the pilot of the Yak 52 received minor injuries. Both airplanes were operated as Title 14 Code of Federal Regulations Part 91 personal flights. According to the pilot of the Yak, they had planned to fly in formation with the Yak as the lead airplane and the CJ-6A following the Yak off its right wing as the “dash 2” (wingman). During the uneventful flight from Watsonville, California, they briefed their detachment procedure over a shared radio frequency. The plan was for them to accelerate from 210 kph to 250 kph, at which time the pilot of the CJ-6A would pitch up and bank left to continue his flight to Payson, Arizona, while the pilot of the Yak would continue straight and level and proceed to San Diego, California. The pilot of the Yak stated that, immediately after they accelerated to their planned speed, he observed the CJ-6A pitch up and bank left. After looking away briefly, he observed the CJ-6A abeam as it began to overbank to about 120° and approached the Yak in an approximately 35° nose low attitude. After the airplanes collided the pilot noticed that his propeller blades had separated, at which time he lost sight of the CJ-6A. A witness observed the CJ-6A roll right four times and then impact the ground, which was immediately followed by a plume of dust. The pilot of the Yak made a left turn as he looked for a suitable place to land and eventually touched down on a nearby road. Figure 1. Flight track of N5287 (Yak) movements at the time of the accident and after. An autopsy of the CJ-6A pilot was completed by the County of Los Angeles, Department of the Medical Examiner, Los Angeles, California. According to the autopsy report, the cause of death was blunt force trauma and the manner of death was an accident. Toxicological testing by the County of Los Angeles Department of the Medical Examiner Forensic Sciences Laboratories detected ethanol at 0.054 g/dL in the pilot’s cavity blood. Further toxicological testing by the FAA Forensic Sciences Laboratory detected ethanol at 0.058 g/dL in the pilot’s cavity blood and at 0.036 g/dL in his gastric contents. Ethanol was not detected in his vitreous fluid. N-propanol was detected in the pilot’s cavity blood and gastric contents, but not in the vitreous fluid. Ethanol is the intoxicating alcohol in beer, wine, and liquor, and, if consumed, can impair judgment, psychomotor performance, cognition, and vigilance. N-propanol is another alcohol that can be produced by microbes in a person’s body tissues and fluids after death. Detection of n-propanol in a postmortem specimen potentially is indicative of postmortem microbial activity in the specimen with or without associated ethanol production. According to the Red StarPilots Association (RPA) website, the organization is composed of over 500 members operating a variety of jet- and propeller-driven aircraft, including Yak and Nanchang airplanes. A family member reported that the accident pilot had owned the Nanchang CJ-6A for about 10 years and had been a member of RPA for about that same length of time. The RPA also reported that the pilot was the president of the organization at the time of the accident. The RPA maintains a Formation Manual that includes instructions on the fundamentals of formation flight and covers basic and advanced maneuvers. In 1993 RPA formed a Formation and Safety Team (FAST) to develop and codify standards for formation flying throughout the warbird community. The manual serves as the basis for these fundamentals, which include wingman procedures and techniques, operating procedures, contingency procedures, communications procedures and techniques, hand signals, and aircraft signals. According to the president of RPA, the maneuver that the two pilots had briefed was not covered in the RPA manual and is not something the organization teaches in its FAST formation training courses. According to the association, the RPA formation manual and 14 Code of Federal Regulations Part 91.11 do not prohibit other formation maneuvers as long as they are thoroughly briefed by the participating pilots. The CJ-6A came to rest upright in desert terrain oriented on a northwestern heading at a field elevation of about 2,310 ft mean sea level. Most of the major structural components of the airplane were accounted for at the accident site except the left elevator. The left side antenna from the vertical stabilizer was located about 0.5 nautical miles west of the main wreckage. A ground scar was located beneath the right wing, and another ground signature was located under the engine. The empennage, which was loosely attached to the aft fuselage, was composed of the vertical stabilizer, both horizontal stabilizers, and the right elevator. The CJ-6A displayed multiple paint transfer signatures, score marks, tears, gouges, and separations. The left wing contained a 3-foot-long tear about midspan, with wooden propeller fragments inside the wing. Yellow paint transfer marks and light grey or white scuffing and track marks were observed aft of the tear. The scuffing was oriented about 25° to the right of the longitudinal axis of the airplane. White/light grey scuffing was also observed on the outboard top skin of the left horizontal stabilizer oriented 47° to the right of the longitudinal axis. The left elevator was not recovered. The leading edge of the left horizontal stabilizer exhibited a chordwise tear and was deformed from midspan to the stabilizer tip, with an impression and paint deterioration at the leading edge of the horizontal stabilizer tip. Additional light grey striated marks were observed on the top skin of the aft fuselage that tracked aft and to the left of the longitudinal axis of theairplane. These fuselage striations were just forward of the leading edge of the vertical stabilizer, which was crushed and partially separated from the fuselage. Postaccident examination of the CJ-6A revealed no preimpact mechanical anomalies or malfunctions with the airframe or engine that would have precluded normal operation. Figure 2. CJ-6A damage signatures after midair collision. The Yak came to rest upright on the right edge of a road about 1.5 nautical miles southeast of the CJ-6A oriented on a southeast heading at a field elevation of about 2,350 ft mean sea level. The airplane’s major structures were accounted for at the accident site. The left wing exhibited a long chordwise tear from about mid span to the trailing edge surrounded by numerous paint transfer marks. The top of the cowling was crushed, a portion of the cowling had separated, and both propeller blades had separated at their blade roots. The left wing of the Yak exhibited white/light grey scuffing that was oriented 47° relative to the longitudinal axis of the airplane. An arching red paint transfer mark that had an approximate diameter of 4 ft 7 inches was observed on the top skin of the inboard left wing. The left-side canopy plexiglass at the aft cockpit was broken and a portion of the left-side canopy frame was bent. About midspan was an approximately 1-ft-7-inch-long gouge along the chordwise axis of the left wing that terminated in a concaved depression. The pilot of the Yak reported no preimpact mechanical malfunctions or anomalies that would have precluded normal operation. Figure 3. Yak damage signatures after midair collision. Occupant Information