SEA99LA093 · Modrow AVID FLYER
Modrow AVID FLYER · Accident: loss of engine power en route
From Bremerton National Airport (PWT) to an unrecorded destination
Event
- NTSB case
- SEA99LA093
- 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
Modrow AVID FLYER
- Aircraft type
- Modrow AVID FLYER
- 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
- N700RM
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Bremerton National Airport (PWT), Bremerton, WATo not recorded
- 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
- Loss of engine power
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Stall
- 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, bearing › Failure
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The Rotax engine in the amateur-built airplane seized while in flight. The pilot performed an emergency landing, with the airplane sustaining substantial damage. NTSB examination of the crankshaft, bearings and rods, and associated componentry, found no evidence of a general lack of lubrication. The labyrinth sleeve, located between the two front (PTO, or power takeoff end) bearings showed evidence of circular scoring and material transfer contact between the bore of the sleeve and the crankshaft surface, similar to that which would occur with foreign matter in the clearance space between the sleeve and crankshaft. A portion of what appeared to be a melted bearing retainer ring was found in one bearing. The flat face on the magneto side of the labyrinth sleeve was darkened and contained foreign material deposits which appeared similar in color and nature to the material of the bearing retainer ring. The PTO side of the labyrinth sleeve was configured with a ring at the inner and outer diameters, with a hollowed out region in between. The hollow contained foreign material deposits, as did the surface of the inner diameter ring. Little discoloration was noted on the PTO side of the labyrinth sleeve. The bore of the labyrinth ring showed a large amount of circumferential scoring and material transfer. The corresponding area on the surface of the crankshaft contained similar scoring and material transfer, consistent with contact between these two surfaces. The ball bearings in both of the PTO bearing assemblies were unevenly spaced, indicating that their retainer rings were either lost or somehow ineffective in keeping the balls evenly spaced.
Probable cause
Engine seizing due to failure of main bearing assemblies. Factors include foreign material in the labyrinth sleeve, and a stall encountered while the pilot was attempting his emergency landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA99LA093
- Event ID
- 20001212X19123
- Case number
- SEA99LA093
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1999-06-23.
- API snapshot SHA-256: 75f3f9c11e0250f2aa7a460398d0104a427e09f1a8fb05e1b8d784dd2dbdae48; retrieved 2026-09-21T20:30:07.941Z.