ERA21LA222 · Mooney Aircraft CORP. M20K
Mooney Aircraft CORP. M20K · Accident: loss of engine power (total) en route
From Orlando Apopka Airport (X04) to Birmingham-Shuttlesworth International Airport (BHM)
Event
- NTSB case
- ERA21LA222
- 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
- 0 · all aircraft and ground
- Ground fatalities
- 0
- 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
- N9514R
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Orlando Apopka Airport (X04), Apopka, FLTo Birmingham-Shuttlesworth International Airport (BHM), Birmingham, AL
- Aircraft age
- About 41 years (built 1980)
- 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
- En route
- 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
- Loss of engine power (total)
- 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 power plant
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot reported that, while en route to the destination airport, the airplane lost total engine power. The pilot declared an emergency with air traffic control and began to divert to the nearest airport. The pilot recognized that the airplane would not be able to glide to the airport, and he decided to land on a road with the landing gear and flaps retracted. The pilot and passenger sustained serious injuries, and the airplane was substantially damaged. A postaccident teardown examination of the engine revealed that the No. 4 connecting rod was fractured midspan. One of the No. 4 connecting rod bolt nuts was found in the oil pan and exhibited no signs of pre- or postaccident damage. The cotter pin for that nut was not found; the other No. 4 connecting rod nut was found secured to its bolt with the cotter pin installed. Additionally, all other connecting rod bolt nuts remained attached to their respective bolts with cotter pins in place. Thus, it is likely that the nut found in the oil pan was not secured with a cotter pin and that the unsecured No. 4 connecting rod bolt nut became loose over time and backed out of the connecting rod bolt during the accident flight, resulting in the total loss of engine power. Review of maintenance records revealed that the engine had accumulated about 1,240 hours of operation since major overhaul, which was completed more than 28 years before the accident. The engine manufacturer recommended that the engine be overhauled every 2,000 hours or 12 calendar years, whichever occurred first. The investigation could not determine when the No. 4 connecting rod nut was installed without a cotter pin.
Probable cause
Maintenance personnel’s failure to properly secure the No. 4 connecting rod bolt nut with a cotter pin, resulting in a total loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA21LA222
- Event ID
- 20210520103119
- Case number
- ERA21LA222
- 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, cause areas. 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: 252bb2a801b6ac91adab5d557bd7f3d01e95b93488ccb124381a28d25d1aae88; retrieved 2026-09-16T14:04:18.462Z.