MIA99LA228 · William John Schulz WJS JAYBIRD WJS JAYBIR
William John Schulz WJS JAYBIRD WJS JAYBIR · Accident: partial loss of engine power (mechanical failure) en route
From Bob White Field (X61) to Mid Florida at Eustis Airport (X55)
Event
- NTSB case
- MIA99LA228
- 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
William John Schulz WJS JAYBIRD WJS JAYBIR
- Aircraft type
- William John Schulz WJS JAYBIRD
- 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
- N735BS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Bob White Field (X61), Zellwood, FLTo Mid Florida at Eustis Airport (X55), Eustis, 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
- First occurrenceThe 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
- Partial loss of engine power (mechanical failure)
- 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
- Engine assembly, rocker arm/tappet › Undertorqued
- Pilot in command › Maintenance, installation, improper
Approximate · Estimated position: the centre of Tangerine, FL, the place the record names. Not the accident site.
NTSB narrative
The pilot stated he was enroute to Mid Florida Airport, Eustis, Florida, when a partial power loss and the inability to hold altitude necessitated a precautionary landing. The pilot said he executed a landing with a left quartering tailwind due to utility lines and trees blocking an approach into the wind. The aircraft bounced, and on the second bounce the right landing gear bent and the wind lifted the left wing. The aircraft slid, and slowly nosed over, coming to rest upside down, resulting in substantial damage to the aircraft. According to the pilot, the reason for engine power loss was due to insufficient torque on the jam nut exhaust valve adjuster (rocker arm) to number 4 cylinder.
Probable cause
the pilot's improper torqueing of a rocker arm adjusting jam nut, that resulted in the adjuster loosening, and a partial loss of engine power. This resulted in the pilot making an off airport precautionary landing and subsequent nose over, during which the aircraft received substantial damage.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MIA99LA228
- Event ID
- 20001212X19595
- Case number
- MIA99LA228
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: 635c4bae4facb3c0872eb5282ad862dbd1cc56f8d37550ecc44bdce6e8d00093; retrieved 2026-09-22T14:19:24.465Z.