ERA09LA238 · Byron J. Moore Zealot
Byron J. Moore Zealot · Accident: loss of engine power (total) en route
From Grass Roots Airpark (06FD) to Grass Roots Airpark (06FD)
Event
- NTSB case
- ERA09LA238
- 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
- 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
Byron J. Moore Zealot
- Aircraft type
- Byron J Moore ZEALOT
- Category
- Glider
- 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
- N61ZT
- Operator
- Fredric P. Griffith · private individual
- Onboard fatalities
- Unknown
- Route
- From Grass Roots Airpark (06FD), Mascotte, FLTo Grass Roots Airpark (06FD), Mascotte, FL
- 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
- En route · cruise
- 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 handling/service
- Aircraft › Fluids/miscellaneous hardware
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot stated that he was in cruise flight at 1,800 feet when the motorized glider experienced a total loss of engine power. He attempted an engine restart with negative results and made a forced landing. The current owner stated that he purchased the motor glider about 4 months before the accident. The engine had been removed by the previous owner, rebuilt, serviced, installed on the glider, and placed in storage. A Federal Aviation Administration inspector disassembled the engine after the accident. Prior to disassembly, the oil tank indicated that it was full of oil. Disassembly of the engine revealed the rotary valve disc drive gear had failed due to insufficient lubrication. There were about 2 ounces of oil drained from the oil bath reservoir. The engine manufacturer's installation manual indicated that if the vent plug in the engine case is not removed when servicing the engine with oil. The oil reservoir can indicate it is full of oil, and an air bubble can form which will prevent oil from filling the chamber. This will result in significant heat, and cause catastrophic failure of the drive gear due to insufficient lubrication. The previous owner stated that he did not remove the vent plug when he serviced the oil after the engine was rebuilt and installed on the motor glider.
Probable cause
A loss of engine power due to oil starvation as a result of the previous owner's improper servicing of the engine oil.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA09LA238
- Event ID
- 20090410X92304
- Case number
- ERA09LA238
- 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. 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: 97d653ff66446eaf30d71d1c13993064f9255f1689e270463444363f68748fcd; retrieved 2026-09-15T10:55:18.433Z.