No fatalities

11 Sep 2021: BEECH 35-B33 (N8983M) — Baker, NV

Baker, NV, United States

On 11 Sep 2021, a BEECH 35-B33 (registration N8983M) was involved in an aviation accident near Baker, NV. No fatalities were reported. Investigators recorded the probable cause as: A total loss of engine power during the initial climb due to the failure of the No. 5 connecting rod bearing. This summary draws on records from NTSB; 10 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

On September 11, 2021, a Beech BE35-B33 (N8983M) suffered a total loss of engine power after takeoff near Baker, Nevada. The pilot performed a forced landing, during which the landing gear collapsed, substantially damaging the aircraft. The pilot was uninjured. Postaccident examination revealed two holes in the crankcase, no engine oil, and fatigue fractures in the No. 5 connecting rod.

Accident Overview

On September 11, 2021, at about 1300 Pacific daylight time, a Beech BE35-B33, registration N8983M, was substantially damaged in an accident near Baker, Nevada. The pilot, who was the sole occupant, was not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.

Pilot Report

According to the pilot, prior to the flight a mechanic replaced the exhaust pushrod for the No. 1 cylinder. The engine was ground tested at various power settings with no anomalies noted, and the mechanic deemed the airplane safe to fly to the pilot's home airport. The pilot departed from a dirt runway. After attaining a positive rate of climb and airspeed, he raised the landing gear. As the gear retracted, he heard a loud bang, followed by a total loss of engine power. The pilot extended the landing gear and executed a forced landing onto open desert terrain. During the landing roll, the nose landing gear and right main landing gear collapsed, resulting in substantial damage to the fuselage and right wing.

Postaccident Examination

Postaccident examination of the engine revealed two holes in the top of the engine crankcase at cylinder Nos. 5 and 6. No oil was indicated on the oil dipstick. The undercarriage of the airframe from the nose to the tail was covered in oil, as was the top portion of the cowling.

NTSB Materials Laboratory Findings

The assemblies for cylinder Nos. 5 and 6, including piston assemblies, connecting rod pieces, and bearing pieces, were examined by the NTSB Materials Laboratory in Washington, DC. The examination showed that portions of the No. 5 connecting rod exhibited a dark tint, consistent with exposure to high heat. The bearing for the No. 5 connecting rod was severely worn, deformed, flattened, and darkened, consistent with high heat exposure. The connecting rod strap was fractured into multiple pieces. One portion near the exterior surface exhibited ratchet marks and curving crack arrest lines, consistent with fatigue. Another portion of the fractured strap showed relatively smooth fracture features with curving crack arrest lines and ratchet marks, also consistent with fatigue. For both portions, the fatigue origins were located at the radius for the attachment bolt boss. Examination of the crankshaft revealed scoring, deposited material, and heat tint damage on the journal for the No. 5 connecting rod. Scoring and pitting damage was observed on the journal for the No. 6 connecting rod. The remaining journals for the connecting rods and the main journals exhibited no damage.

Contributing factors

Aircraft power plant — FailureFatigue/wear/corrosion