SEA06CA108 · Grumman AA-1B
Grumman AA-1B · Accident: airframe, component or system failure en route
From Skypark Airport (BTF) to Skypark Airport (BTF)
Event
- NTSB case
- SEA06CA108
- 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
Grumman AA-1B
- Aircraft type
- Grumman AA-1
- 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
- N8866L
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Skypark Airport (BTF), Bountiful, UTTo Skypark Airport (BTF), Bountiful, UT
- 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
- Airframe, component or system 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
- Pilot in command › Distance/altitude, misjudged
- Window, flight compartment window/windshield › Obstructed
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 this was the first flight following the airplane's annual inspection. The flight departed on runway 16 and proceeded to a point 5 to 10 miles south of the airport, "when there was a gush of oil from the front of the plane that covered the windshield." The pilot was not able to see through the windshield "at all." She returned to the airport and attempted to land on runway 34, but was "too high and fast." The pilot then entered the traffic pattern for runway 16. After landing, she applied the brakes, "but by then there was not much runway left." The airplane overran the runway and impacted a metal pipe. According to an FAA inspector who examined the airplane, the nose gear collapsed and there was damage to the firewall. The inspector determined that the source of oil on the windshield was a displaced crankshaft seal. Examination of the airplane's maintenance records by the inspector revealed that the mechanic who performed the annual inspection had replaced the crankshaft plug, but not the crankshaft seal.
Probable cause
An obstructed windshield which resulted in the pilot misjudging the distance/altitude during an emergency landing. An oil leak as a result of a leaking crankshaft seal was a factor.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA06CA108
- Event ID
- 20060628X00846
- Case number
- SEA06CA108
- 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, 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: c2992b4f6402ec8eb4be1d317192c77b93b50435306b5bff73c060bc556f793c; retrieved 2026-09-21T18:45:41.949Z.