NTSB Factual Report

HISTORY OF FLIGHT

On May 25, 2015, at 0818 mountain daylight time, a Yakovlev Yak 52 airplane, N124FS, was substantially damaged during an in-flight collision terrain near Syracuse, Kansas. The pilot was fatally injured. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The local flight originated from the Syracuse-Hamilton County Municipal Airport (3K3), Syracuse, Kansas about 0755.

A friend of the accident pilot, who also owned a Yak 52, stated that they had planned to meet at the airport about 1000 to conduct a fly-by in conjunction with the local Memorial Day events. When he arrived at the airport about 0900, the accident pilot's car was there, but his airplane was gone. He noted that the accident pilot commonly used his airplane to check on his cattle. He attempted to contact the accident pilot over the radio without success. He subsequently took off about 1000 and held north of town. When the accident pilot did not arrive, he conducted a single airplane fly-by. He was notified of the accident after returning from the flight.

A witness reported that the airplane was initially eastbound. She observed it make a right 180-degree turn to a west course. The airplane then "dipped down" (descended) until she lost sight of it momentarily, before it climbed back up. She noted that the airplane banked again and she was able to see both wings. She added that the wings were red, while the body of the airplane was white. The airplane leveled off and then "dipped" again, causing her to momentarily lose sight of it again until it climbed up. The airplane then began what appeared to be a normal turn to the left toward the south when it "fell straight down." She explained that it did not appear to bank, but that it nosed down. The airplane descended below her line of sight and she heard a "funny" sound. When the airplane did not climb back up again, she thought that it had crashed. She notified the local authorities at that time.

Authorities received a call regarding a possible airplane crash at 0819. The accident site was located about 1130 after an extensive search of the local area.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with single-engine land airplane rating. He was issued a third class airman medical certificate with a limitation for near and distant vision corrective lenses on September 12, 2013. On his medical certificate application, the pilot noted a total flight time of 1,000 hours, with no flight time within the preceding six month time period.

The pilot's logbook was reviewed by the NTSB. According to the logbook, the pilot had accumulated a total flight time of about 656 hours in single-engine land airplanes, 541 hours as pilot-in-command, 99 hours dual instruction received, and 31 hours night flight time. The initial logbook entry was dated October 25, 1994, and appeared to correspond to the accident pilot's initial flight lesson. Three entries corresponding to the accident airplane were dated November 6, 2011; November 27, 2011; and November 28, 2011. These entries totaled 5.1 hours. The next and final logbook entry was dated November 27, 2014. According to the entry, this flight was conducted in a Beech V35A airplane. This entry also included a remark, "Flight Review." However, a complete flight review endorsement was not located in the logbook. The logbook did include an endorsement for the operation of high-performance airplanes.

With respect to recording flight time, pilots are required to document the flight training and aeronautical experience used to meet the requirements for a rating, certificate, flight review, or recent flight experience as specified by the regulations. (Ref: 14 CFR 61.51) However, pilots are not required to document all flight time.

AIRCRAFT INFORMATION

The accident airplane was a 1981 Yakovlev Yak-52, serial number 811614. It was a two-place, tandem seating, single-engine airplane, with a retractable tricycle landing gear configuration. The airplane was powered by a 360-horsepower, nine-cylinder Vendeneyev M14P radial engine, serial number KR032039. The accident airplane was issued an FAA experimental category, exhibition airworthiness certificate in May 1993. The accident pilot purchased the airplane in October 2011.

According to the airplane maintenance records, the most recent condition inspection was completed on May 1, 2014. At the time of that inspection, the airframe and engine had accumulated 2,661.3 hours and 947.2 hours total time, respectively. The recording hour (Hobbs) meter indicated 1,174.4 hours at that time. No subsequent maintenance entries were recorded in either the airframe or the engine logbook. The recording hour (Hobbs) meter was damaged and a definitive reading could not be obtained.

METEOROLOGICAL INFORMATION

Weather conditions recorded by the 3K3 Automated Weather Observing System, at 0815, were: wind from 280 degrees at 3 knots, 10 miles visibility, clear sky, temperature 13 degrees Celsius, dew point 11 degrees Celsius, and an altimeter setting of 29.84 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The airplane impacted an open field about 3 miles southeast of 3K3. The fuselage was oriented on an approximate 230-degree magnetic heading. A ground impact mark was located about 21 feet west of the main wreckage. The impact mark was about 31 feet long and up to about 1.75 feet deep. The initial portion of the impact mark was oriented on an approximate 090-degree bearing, while the final portion was oriented about 110-degrees. The outboard portion of the right wing, about 5 feet in length, and the right main wheel assembly were located adjacent to and in the impact mark, respectively. Local authorities reported a small fuel spill at the accident site. A wetted area of ground with a faint fuel odor was observed adjacent to the left wing fuel tank during the on-scene examination.

The main wreckage consisted of the remainder of the airplane; specifically, the cowling, engine, propeller, fuselage, remaining portion of the right wing, the entire left wing, and the empennage. The engine cowling was deformed and partially separated. The engine was dislocated aft and to the right, with corresponding damage to the engine mount. The fuselage was deformed along its entire length. The forward and aft cockpit areas were deformed and compromised.

The left wing was dislocated relative to the fuselage, but remained attached. The wing exhibited leading edge crushing over the inboard and outboard portions. The inboard portion of the wing spar was bent forward, with corresponding deformation and tearing of the inboard closure rib. The lower-forward spar attachment lug was bent forward and partially separated; appearance of the fracture surface was consistent with overstress failure. The left wing attachment lugs on the fuselage carry-through spar were intact. The wing attachment bolts were securely installed. The left main fuel tank was deformed and breached within the wing structure. The left main landing gear assembly remained attached to the wing and was in the up and locked position when observed during the on-scene examination.

The left aileron and flap remained attached to the wing; however, the aileron was dislocated outboard. Aileron control continuity was confirmed to the wing root. The aileron push-pull control tube was separated at the wing root consistent with an overstress failure. The flap push-pull control tube was dislocated inboard. The connecting links between the control tube and flap had separated from the flap, remaining attached to the control tube. The fracture surfaces appeared consistent with overstress failures. The flap connecting rod linkage remained attached to the fuselage actuator and was disconnected to facilitate recovery.

The outboard 5-foot section of the right wing had separated from the remainder of the wing assembly. It was located 20 feet west of the main wreckage immediately adjacent to the ground impact scar. The leading edge exhibited aft crushing at the tip and the entire wing section was deformed. The right aileron remained attached to the wing section. The entire aileron was deformed similar to the wing section. The center section of the aileron torque tube exhibited separations from the inboard and outboard sections near the hinges, with the separations consistent in appearance to overstress failures. The aileron control tube remained attached to the control surface. However, the control tube was separated about one foot forward of the aileron attachment point; that separation also appeared consistent with overstress failure. A portion of the wing spar had separated from the outboard wing section. The spar section was deformed. The outboard aileron bellcrank remained attached to the spar section, with portions of the aileron control tube and aileron push-pull tube attached. Appearance of the tube separations was consistent with overstress failure.

The inboard portion of the right wing remained partially attached to the fuselage at the spar. The inboard wing exhibited leading edge crushing and deformation over the entire section. The wing skin had separated from the spar over the outboard portion of the wing section. The spar was separated near mid-span; however, the separation appeared consistent with an overstress failure. The inboard wing spar attachment lugs were intact. The upper attachment lug common to the fuselage carry-through spar had separated, with the lug remaining attached to the wing spar. Appearance of the fracture surface was consistent with overstress failure. The lower attachment lug remained secured to the lug on the fuselage carry-through spar. The wing attachment bolts remained securely installed. The aileron push-pull tube common to the mid-section of the wing, including the mid-span bellcrank, was intact. Tube separations at the inboard and outboard ends of the wing section were consistent in appearance with overstress failures. The flap remained attached to the wing. The push-pull control tube and corresponding connecting links remained attached to the flap. The inboard end of the push-pull control tube exhibited a fracture surface consistent with an overstress failure. The right main landing gear strut remained attached to the trunion. The trunion remained secured to the wing; however, the underlying wing structure had partially separated from the wing. The main wheel assembly had separated from the strut and was located at the impact mark. The landing actuator remained attached to the wing, but had separated from the strut.

The empennage appeared intact, with the exception of the right horizontal stabilizer and elevator. The right horizontal stabilizer was deformed aft and upward over the entire span. The right elevator was separated and located at the accident site; the elevator was deformed consistent with impact.

Three cylinders were dislocated from the crankcase, but remained with the engine. One propeller blade was separated at the hub and fragmented. The outboard one-foot portion of the blade (blade tip) was recovered at the accident site, about 21 feet east-northeast of the main wreckage. The second propeller blade remained attached to the hub. That blade exhibited a delamination near mid-span, but appeared otherwise intact. All flight controls were located at the accident site.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy of the pilot was conducted at Brock's Mortuary, Hays, Kansas, on May 26, 2015, by the District Coroner, XXVI Judicial District of Kansas. The pilot's death was attributed to multiple blunt traumatic injuries sustained in the accident.

The FAA Civil Aerospace Medical Institute toxicology report stated:

Atenolol detected in Liver

0.053 (ug/mL, ug/g) Atenolol detected in Blood (Cavity)

Diphenhydramine detected in Liver

0.181 (ug/ml, ug/g) Diphenhydramine detected in Blood (Cavity)

14.478 (ug/mL, ug/g) Fluoxetine detected in Liver

0.896 (ug/mL, ug/g) Fluoxetine detected in Blood (Cavity)

Losartan detected in Liver

Losartan detected in Blood (Cavity)

Norfluoxetine detected in Liver

Norfluoxetine detected in Blood (Cavity)

Atenolol and losartan are blood pressure medications available by prescription, commonly marketed with the names Tenormin and Cozaar (atenolol is a beta-blocker). Diphenhydramine is a sedating antihistamine available over-the-counter in a number of products intended for the treatment of allergies, colds, and insomnia including some using the Benadryl and Unisom brand names. Fluoxetine is a prescription antidepressant commonly marketed with the name Prozac.

TESTS AND RESEARCH

GPS data related to the accident flight was recovered from a handheld GPS receiver. The initial data point was recorded at 0741 near the hangar area at 3K3. The data indicated that the pilot taxied to runway 31 and departed about 0755. After takeoff, the pilot proceeded west of the airport about 6 miles before reversing course; the airplane's altitude was about 3,500 feet during this portion of the flight. About 0803, the pilot maneuvered in an area about 1.5 miles to 3.0 southwest of the airport for approximately 6 minutes. The range relative to the airport was 1.25 miles to 3.25 miles, and altitudes varied from about 3,350 feet to about 4,450 feet, during that timeframe. Beginning about 0812, the pilot flew along the Arkansas River for about 4 miles before turning south and maneuvering south-southeast of the airport at altitudes ranging from about 3,500 feet to 4,100 feet. The final data point was recorded at 0817:51 (hhmm:ss). It was located 2.95 miles southeast of the runway 31 threshold and about 394 feet west of the accident site. The associated altitude was 3,714 feet, which was about 500 feet above ground level.

Shortly before the accident, the pilot overflew a residence located about 0.25 mile northeast of the accident site. The first overflight occurred at 0817:00, after which the pilot entered a left turn and flew a 0.60 mile long holding pattern type course and returned for a second overflight about 40 seconds later. The altitudes associated with the first and second overflights were 3,317 feet and 3,589 feet, respectively. Immediately after the second overflight, the airplane appeared to enter a left turn. The final data point was recorded after the airplane had completed about 90 degrees of heading change in that turn. The calculated average groundspeed over the final 10 seconds of GPS data was about 101 knots.

ADDITIONAL INFORMATION

A Pilot's Operating Handbook/Flight Manual specific to the accident airplane was not available to the NTSB. However, based on the accident airplane airspeed indicator markings, the wings level, flaps up aerodynamic stall speed was about 60 knots. The flaps down stall speed was approximately 55 knots. These airspeeds corresponded to online references attributed to Yak 52 airplanes.

The FAA Pilot's Handbook of Aeronautical Knowledge and Airplane Flying Handbook provide information related to aerodynamic stalls. The handbooks note that the aerodynamic stall speed is greater when an airplane is in a constant altitude or climbing turn as compared to when in straight and level flight.

NTSB Probable Cause

The pilot’s failure to maintain airplane control while maneuvering at low altitude, which resulted in the airplane’s wing exceeding its critical angle-of-attack and a subsequent aerodynamic stall .