Beech 58TC accident near Mesa, Colorado, October 11, 2021
On October 11, 2021 at about 2:57 pm local time, a 1980 Beech 58TC, registered N6748V, was destroyed in an accident during enroute near Mesa, Colorado. It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 11, 2021 · about 2:57 pm local time
- Place
- Mesa, Colorado · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech 58TC, built 1980 · all 58TCs on the register
- Registration
- N6748V · registry record · serial TK-120
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of control in flight during enroute defining event
- Loss of engine power (partial) during enroute
The NTSB's findings
- Personnel issues › Task performance › Maintenance › Installation › Maintenance personnel
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › (general) › Not attained/maintained
- Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Aircraft › Aircraft systems › Equipment/furnishings › Flight compartment equipment › Not used/operated
Pilot
- Certificate: private
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 3,851 hours in all; 0 in the last 90 days; 0 in the last 30 days
- Last flight review: October 1, 2019
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 3,429.3 hours
- Last inspection: annual inspection, October 1, 2021; 0 hours since
- Maximum gross weight: 6,240 lb
- Seats: 6
- Landing gear: retractable
- Engine 1: Cont Motor TSIO-520-WB (piston); 3,429 hours total
- Engine 2: Cont Motor TSIO-520-WB (piston); 3,429 hours total
The flight
- Departed from: AJZ Delta CO at 2:43 pm
- Destination: RKS Rock Springs WY
- Flight plan: IFR
Weather at the time
- Light: daylight
- Wind: from 100° at 15 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 46°F (8°C), dew point 34°F (1°C)
- Altimeter: 29.83 inHg
- Observation at 8:53 am from KGJT, 20 miles away
Weather report (METAR): KGJT 111453Z AUTO 10015KT 10SM CLR 08/01 A2983 RMK AO2 PK WND 11026/1354 SLP074 T00830011 57014
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
13 documents, released by the NTSB on September 7, 2023. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | NTSB Investigation Summary | PDF, 13 pages · our copy | View Download |
| 2 | Maintenance Records | PDF, 33 pages · our copy | View Download |
| 3 | Memorandum for Record A�� Mechanics | PDF, 3 pages · our copy | View Download |
| 4 | Fuel Receipt | PDF, 1 page · our copy | View Download |
| 5 | Pilot Logbook Excerpts | PDF, 11 pages | View Download |
| 6 | Photos | PDF, 18 pages · our copy | View Download |
| 7 | Autopsy Memo | PDF, 1 page · our copy | View Download |
| 8 | Toxicological Report | PDF, 1 page · our copy | View Download |
| 9 | Statement of Party Representatives to NTSB Investigation | PDF, 1 page · our copy | View Download |
| 10 | Release of Aircraft Wreckage, NTSB Form 6120.15 | PDF, 1 page · our copy | View Download |
| 11 | Air Traffic Control Recording | video · our copy | View Download |
| 12 | Air Traffic Control - Track Data (Opsvue) | data file · our copy | Download |
| 13 | Video File - FBO Surveillance Video of Accident Takeoff | MOV file · our copy | Download |
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.
