N93316

HISTORY OF FLIGHTOn January 29, 2018, about 0945 Pacific standard time, a Cessna 152, N93316, was substantially damaged when it impacted terrain near Concord, California. The airline transport pilot was fatally injured. The airplane was privately owned and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed in the area and no flight plan was filed. The flight originated from Buchanan Field Airport (CCR), Concord, California, about 0936, with an unknown destination.

About 0935, the CCR tower controller cleared the pilot for takeoff from runway 19L. Shortly after takeoff, at 0938, the controller advised the pilot that a frequency change was approved, which the pilot acknowledged. There were no further radio communications from the pilot, and there was no available radar data that correlated to the accident airplane.

A local rancher who drove into the area of the accident site about 1000 - 1005 that morning, noticed the airplane wreckage and notified the local authorities. He stated that the weather at the time was clear and there was no wind. Furthermore, he stated that the security guards at the gate located about 3/4 mile west of the accident site, mentioned that they heard a "screeching sound" about 0945 before he arrived in the area. One of the security guards stated that the weather was hazy but the visibility good, as he could see the mountains to the east. PERSONNEL INFORMATIONThe pilot held an airline transport pilot certificate with a rating for airplane multiengine land with commercial privileges for airplane single-engine and private privileges for glider. In addition, he held a flight instructor certificate for airplane single-engine. The pilot was issued a third-class Federal Aviation Administration airman medical certificate on May 23, 2016, with a limitation that stated, "must have available glasses for near vision." On the application for this medical certificate, the pilot reported 3,040 total hours of flight experience, with 60 hours in the 6 months before the exam.

The medical certificate expired on May 31, 2017. The pilot's BasicMed comprehensive medical examination checklist was dated May 12, 2017, and he completed the BasicMed course on July 16, 2017.

Records obtained from the physician who the pilot had reported was his BasicMed examining physician, revealed no evidence that the pilot had been seen for a BasicMed examination. Additionally, the office staff said that they had no appointment records of a visit by the accident pilot on the reported date. AIRCRAFT INFORMATIONThe two-seat, high-wing, fixed-gear airplane was manufactured in 1981. It was powered by a Lycoming O-235 engine rated at 110 horsepower and was equipped with a fixed-pitch propeller.

The airframe and engine maintenance logbooks were not located. METEOROLOGICAL INFORMATIONAt 0953, the recorded weather observation at CCR, included calm wind, 5 miles visibility in mist, clear sky, temperature 11°C, dew point 9°C, and an altimeter setting of 30.29 inches of mercury. Previous observations from CCR indicated restricted visibility conditions due to mist from 0553 through 0953.

No precipitation was reported or forecasted for the area. No SIGMETs were valid in the area at the time of the accident. AIRMET Sierra was issued for IFR conditions for the interior part of California at 0645, valid through 1300. Modeling estimated the wind to be from 060° about 10 knots, the probability of light turbulence, and a potential for low-level wind shear at the accident site. AIRPORT INFORMATIONThe two-seat, high-wing, fixed-gear airplane was manufactured in 1981. It was powered by a Lycoming O-235 engine rated at 110 horsepower and was equipped with a fixed-pitch propeller.

The airframe and engine maintenance logbooks were not located. WRECKAGE AND IMPACT INFORMATIONThe wreckage was located at an elevation of about 156 ft mean sea level. The airplane impacted level terrain in a near wings level and steep nose-down attitude. The airplane came to rest upright and was oriented on a heading of about 270°.

The first point of impact was identified by impressions in an asphalt road and adjacent dirt consistent with the landing gear and right wing. The propeller blade tip was located in the disturbed area of the asphalt and dirt, just forward of the landing gear impressions. The main wreckage came to rest about 290 ft from the initial impact point; windscreen fragments and various airplane components were scattered along the debris path.

The airplane's wings remained attached at their respective wing roots and were angled downward about 45.º Both wing's leading edges sustained substantial damage. Both flaps and ailerons were attached. Fuel was observed in both tanks, about several inches in depth pooled at the leading edge portion of the tanks. Both fuel caps were examined and were intact. The flaps were observed in the retracted position. The cabin area was crushed. The empennage appeared to be intact. Flight control continuity was established with the ailerons to the wing root and with the elevators to the aft portion of the cabin. Rudder continuity could not be established. Due to the impact damage, most of the flight instruments could not be observed.

All engine components and accessories were present except the carburetor, which had separated and was located about 30 ft past the main wreckage to the south. The engine remained partially attached to the airframe. All rocker covers were removed, and the cylinder overhead areas were observed to be lubricated and unremarkable. The crankshaft was rotated by hand, using a tool attached to the rear gear section; rotational continuity was established throughout the engine, accessory section, and valve train. During crankshaft rotation, thumb compression and suction were obtained on all cylinders. A borescope inspection of the cylinders revealed normal operational signatures.

The two-bladed propeller separated from the crankshaft propeller flange. One blade was bent aft and twisted back about mid-span. A 2-to-3 inch section of the second blade's tip was separated. Portions of the blade tip were located near the initial impact point.

The top sparkplugs were removed; all the spark plug electrodes were normal in color and exhibited normal to worn-out wear signatures when compared to the Champion Check-a-Plug comparison chart. The left and right magnetos were removed and produced spark on their ignition leads when rotated by hand.

The carburetor sustained substantial impact damage and the fuel bowl section had separated. The fuel bowl was clear of contamination, the main jet was free of obstructions, and the float assembly was destroyed during the accident sequence. The vacuum pump was intact; disassembly revealed that the drive shaft was intact, and no anomalies were noted.

The onsite examination of the airplane engine revealed no evidence of pre-impact mechanical malfunctions or failures that would have precluded normal operation.

A follow up examination of the airframe revealed that the right rudder cable was separated at multiple locations where it passed through the aft bulkhead. The cable did not display evidence of corrosion. Evidence of rubbing was observed on the lower portion of the bulkhead. The left rudder cable was frayed and partially separated in the same area. No additional evidence of mechanical malfunction was noted. MEDICAL AND PATHOLOGICAL INFORMATIONThe Contra Costa County Office of the Medical Examiner, Costa County, California, conducted an autopsy on the pilot. The medical examiner determined that the cause of death was "multiple blunt force injuries."

The FAA's Forensic Sciences Laboratory performed toxicological testing on the pilot. Testing was negative for carbon monoxide and volatiles. Bupropion and its metabolite, hydroxybupropion, were detected in the liver and cavity blood (0.086 µg/ml and 0.197 µg/ml respectively); cetirizine was detected at 0.011 µg/ml in cavity blood; and metoprolol were detected and atorvastatin in blood and liver. Metoprolol and atorvastatin are generally not considered to be sedating or impairing.

Bupropion is an antidepressant used to treat depression and help patients quit smoking, often marketed with the names Wellbutrin and Zyban. It carries two warnings: 1) a dose dependent risk of seizures; and 2) may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery). Bupropion's half-life ranges from 4 to 24 hours, it is transformed to a less active metabolite hydroxybupropion. In depressed patients, the maximum improvement in symptoms occurs at plasma levels between 0.050 and 0.100 µg/ml.

Cetirizine is a sedating antihistamine available over the counter and by prescription, often marketed with the name Zyrtec. It is also the active metabolite of hydroxyzine. It carries the following warning for patients, "When using this product, drowsiness may occur, avoid alcoholic drinks, alcohol, sedatives, and tranquilizers may increase drowsiness, and be careful when driving a motor vehicle or operating machinery." The dose dependent accepted therapeutic blood levels range is from 0.170 to 1.45 µg/ml.