Accident Overview
On January 22, 2020, at 1211 Pacific standard time, a Beech B36TC Bonanza (registration N36TT) was substantially damaged in an accident near Corona, California. The aircraft was operating as a Title 14 Code of Federal Regulations Part 91 personal flight. The two pilots and two passengers on board sustained fatal injuries.
Flight History
The flight originated from Corona Municipal Airport (AJO) after refueling. The aircraft landed on runway 7 and taxied to a self-serve fuel tank, where the left-seated pilot added 78.06 gallons of fuel. The right-seated pilot paid, and they departed about 30 minutes later. A witness observed a backfire during engine start, characterized by a loud bang, black smoke, and an arcing sound. The witness later saw the aircraft depart.
Review of airport security camera video showed the aircraft midway down the runway at a relatively level pitch attitude. It briefly became airborne, then touched down again. The windsock indicated an estimated 5-knot tailwind. The aircraft again became airborne but remained close to the runway, with wings rocking. It flew over about 200 feet of grass. In the final 5 seconds on the runway, its ground speed was about 65 knots, increasing to 70 knots, consistent with a 0.057 G acceleration. The aircraft touched down just before contacting a 6-foot-high chain-link airport perimeter fence. It then struck a berm, became inverted, and traveled over the berm before coming to rest on the east side. The aircraft was consumed by a post-impact fire. Witnesses reported the aircraft lifted off about one-third down the runway, assumed a nose-high attitude, and bounced back down several times.
Personnel Information
The left-seat pilot’s personal notebook, recovered from the wreckage, indicated about 45 flight hours in the past year and an estimated 3.7 hours in the accident airplane over three flights, the last in April 2019. It was unknown whether he acted as pilot-in-command on those flights. He owned and regularly flew a 1978 Piper PA-28-161 Warrior II, equipped with a Lycoming O-320 engine and lever-type throttle quadrant.
The right-seat pilot owned the accident airplane. According to aircraft logbooks, he had flown over 650 hours in the airplane—about 5 hours in 2019, none in 2018, and 5 hours in 2017. His personal logbooks were not located.
Aircraft Information
The Beechcraft B36TC Bonanza is an all-metal, low-wing airplane accommodating four to six seats. It was equipped with vernier-style push-pull controls for throttle, propeller, and mixture, located on the control console below the control wheel column. The airplane had traditional toe brakes on both main landing gear, with optional copilot brake pedals installed. It also featured optional dual control columns (T-Type), providing control yokes for both front seats.
Weight and Balance
Weight and balance computations were based on an empty weight of 2,662 lbs from the last weight record in 1998. The fuel quantity at the time of the accident was unknown. Calculated takeoff conditions assumed either 85 gallons (78 added plus 7 estimated remaining) or a full 102 gallons. At 85 gallons, gross weight was 3,813 lbs with a center of gravity (CG) of 82.6 inches. At 102 gallons, gross weight was 3,910 lbs with a CG of 83.1 inches. The maximum authorized gross takeoff weight was 3,850 lbs, with a CG range of 80 to 87.7 inches. The Pilot's Operating Handbook (POH) specified a takeoff distance of about 1,400 feet at maximum gross weight with flaps retracted, a rotation speed of 70 knots, and 82 knots to clear a 50-foot obstacle.
Wreckage and Impact
The accident site was in soft dirt about 360 feet from the departure end of the runway. The main wreckage, consisting of the engine and fuselage remains, came to rest inverted near tall brush, with surrounding terrain burned within 5 to 10 feet. The aircraft was largely consumed by post-impact fire; most fuselage, wings, and skin panels were destroyed.
Initial ground contact marks were parallel indentations about 105 inches apart in vegetation. These continued toward the fence, where four fence posts were folded over. A center indentation appeared between the wheel tracks. The craters matched the landing gear dimensions. The marks extended about 20 feet up a berm.
Engine Examination
Postaccident examination found no evidence of catastrophic engine failure. All cylinders had a light oil film; combustion chambers were undamaged. Dirt ingestion appeared to result from a broken intake manifold during impact. Manual rotation of the crankshaft yielded thumb compression on all cylinders. Magnetos produced spark when rotated. The turbocharger shaft moved freely.
The throttle, mixture, and propeller control knobs were found full forward, but it could not be determined if that was the impact setting due to possible cable movement. The auxiliary fuel pump switch was in the off position. The flaps lever was at 0°, and the landing gear lever was in the extended position.
Control continuity was established to melted bellcranks and airframe portions. Only the left control yoke remained; the right yoke was consumed by fire. The elevator trim tabs were found in the full down position (full nose-up trim), with an actuator measurement of about 2 inches, corresponding to 27° tab down—the maximum travel limit. The POH specified a takeoff elevator trim setting of 3° nose-up.
The landing gear were down, and the flaps appeared up.