Beechcraft 58TC N6748V

Summary

On 11 October 2021 at about 14:57 local time, a Beechcraft 58TC registered N6748V was involved in an accident near Mesa, Colorado, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

11 October 2021 at 14:57

Classification

Accident

Location

Mesa, Colorado, United States

Coordinates

39.2065, -108.1237

Aircraft

Beechcraft 58TC

Registration

N6748V

Category

Airplane

Year built

1980

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Delta → Rock Springs

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

CEN22FA011

1 person died.

The maintenance personnel’s failure to properly tighten the turbocharger oil line and the right engine propeller governor, which resulted in a loss of engine power. Contributing to the accident was the loss of airplane control following the loss of engine power.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot departed on a personal flight that was the first flight after completion of the airplane’s most recent annual inspection. Recorded air traffic control communications revealed that pilot had climbed through 11,000 ft for 14,000 ft. The flight track showed that, after the airplane reached 14,000 ft, it descended about 1,000 ft, climbed to 15,000 ft, and then descended rapidly toward terrain. The airplane impacted a rocky mountainside about 25 nautical miles north of the departure airport. The wreckage debris path was about 30 ft long and consisted mostly of paint chips, shards of windscreen, various small debris, and a large outboard section of the right wing that had separated on impact. The empennage was distorted to the left and remained partially attached to the rear fuselage. The bottom of the airplane exhibited impact damage and scoring from the rocky terrain. The left engine was mostly separated from the leftwing nacelle, and the right engine remained attached to the right-wing nacelle. All six propeller blades were relatively undamaged and did not exhibit leading-edge damage or scoring, which was consistent with minimal, if any, rotation during impact. The right engine compartment, propeller blades, and right-side nose compartment were covered in a layer of engine oil. The engine throttle levers were found near the idle position, and the mixture and propeller control levers were found near the forward position. The pilot’s seatbelt and shoulder harness were not latched during the accident and the pilot was ejected from the airplane. On the right engine, the oil line from the turbocharger wastegate control valve outlet to the inlet side of the turbo pressure controller was loose at the wastegate outlet end. Also on the right engine, the propeller governor had fractured near the mounting base and remained attached to the mounting pad, but three of the four mounting nuts were loose. According to a discrepancy in the maintenance records from the most recent annual inspection, oil was found around the right engine propeller governor. Although the corrective action noted in the maintenance records was to remove the left engine propeller governor and install a new gasket, the mechanics indicated that the reference to the left engine was likely an inadvertent error and that they actually replaced the gasket on the right engine. However, the right engine propeller governor was not properly reinstalled. It is also likely that the turbocharger oil line was not properly tightened. These loose connections likely resulted in a loss of oil during the flight, which led to a loss of engine power. The pilot likely experienced difficulty handling the airplane during the emergency and lost control of the airplane.

Quoted verbatim from the NTSB record.