ERA11FA406 · Mooney Aircraft CORP. M20K
Mooney Aircraft CORP. M20K · Accident: part(s) separation from aircraft during initial climb
From Augusta Regional At Bush Field (AGS) to Augusta Regional At Bush Field (AGS)
Event
- NTSB case
- ERA11FA406
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 1 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Mooney Aircraft CORP. M20K
- Aircraft type
- Mooney M20
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N777CV
- Operator
- Wilson Thomas S MD · private individual
- Onboard fatalities
- Unknown
- Route
- From Augusta Regional At Bush Field (AGS), Augusta, GATo Augusta Regional At Bush Field (AGS), Augusta, GA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Initial climb
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Part(s) separation from aircraft
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft oper/perf/capability
- Aircraft › Aircraft propeller/rotor
- Personnel issues › Action/decision
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, not marked as estimated; no uncertainty radius is established.
NTSB narrative
Maintenance personnel reported that, 2 days before the accident, they were hired by the pilot to prepare the airplane for a maintenance ferry flight following a gear-up landing. While inspecting the airplane, the mechanic noted that the three-blade propeller was bent, so he removed it. Subsequently, the pilot provided maintenance personnel with a two-blade propeller, which they installed. However, when the mechanic attempted to replace the spinner, it would not fit properly. Therefore, he did not sign off the logbooks and advised the pilot that the airplane should not be flown. Review of the airplane's records revealed that the airplane had a supplemental type certificate for an engine conversion kit that required a three-blade propeller.
On the day of the accident, another mechanic conducted a run-up of the engine and noted that the propeller was not working correctly. The supplier of the two-blade propeller advised the mechanic that the airplane should not be flown in that condition. The mechanic discussed the anomaly with the pilot and advised him not to fly the airplane until the issue was resolved. The pilot acknowledged the discrepancy but chose to fly the airplane. Shortly after takeoff, witnesses observed the propeller separate from the airplane. Subsequently, the airplane spiraled to the ground in a nose-down attitude.
Examinations revealed that the propeller attachment bolts had failed, which resulted in the separation of the propeller from the airplane. Five of the six propeller mounting studs exhibited evidence of high-stress fatigue cracking, which indicates that a severe spectrum of cyclic loading in the propeller/engine system occurred, likely as the result of using an unapproved propeller on the airplane.
Probable cause
The pilot’s decision to fly the airplane after maintenance personnel advised him that the airplane should not be flown because the pilot provided an incorrect propeller for installation and the subsequent failure of the propeller attachment bolts and the separation of the propeller.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA11FA406
- Event ID
- 20110718X33733
- Case number
- ERA11FA406
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 8161f8e12253c1e028a0dfdc2da6ed37bdb3e0617b67f06ea7ef54090211834f; retrieved 2026-09-13T21:35:58.616Z.