MIA92LA139 · Extra Flugzeugbau 300
Extra Flugzeugbau 300 · Accident: airframe, component or system failure en route
From 1X4 · Boynton Beach, FL to Dover Civil Air Terminal/Dover Air Force Base (DOV)
Event
- NTSB case
- MIA92LA139
- 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
Extra Flugzeugbau 300
- Aircraft type
- Extra 300
- 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
- N300XL
- Operator
- Lillberg, John W. & Leslie J.
- Onboard fatalities
- Unknown
- Route
- From 1X4 · Boynton Beach, FLTo Dover Civil Air Terminal/Dover Air Force Base (DOV), Dover, DE
- 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 › Visual lookout, restricted
- Propeller system/accessories, governor › Open
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
DURING CRUISE FLT THE PLT REPORTED THAT THE ENG RPM INCREASED WITHOUT MOVEMENT OF ANY COCKPIT CONTROL. HE RETARDED THEN ADVANCED THE THROTTLE BUT THE ENG RPM DID NOT GO HIGHER THAN 1,700. DURING THE EMERGENCY DESCENT, OIL BEGAN COVERING THE WINDSCREEN. HE TURNED TO LAND AT A NEARBY AIRPORT BUT DIVERTED TO A CLOSER ARPT. WHILE ON FINAL APCH TO A RWY, HE REALIZED THAT THE FLT WAS HIGH & FAST & ADDED POWER TO GO AROUND, BUT THE ENG RPM DID NOT INCREASE. HE PERFORMED A 290-DEGREE TURN & LANDED LONG ON AN ADJACENT GRASS RWY. THE AIRPLANE TRAVELLED OFF THE END, THROUGH A FENCE, THEN CAME TO REST IN A DITCH. EXAM OF THE ENG COMPARTMENT REVEALED THAT THE COVER ASSY OF THE PROPELLER GOVERNOR SEPARATED FROM THE BODY. THE COVER IS SECURED TO THE BODY BY A CLAMP. THE CLAMP WAS TIGHTLY SECURED TO THE BODY. THE GOVERNOR HAD BEEN MODIFIED IN 1988 AFTER MANUFACTURE & HAD ACCUMULATED 430 HRS. THE ACFT HAD ACCUMULATED 530 HRS SINCE MANUFACTURE. THE GOVERNOR HAD BEEN REMOVED & REINSTALLED SEVERAL TIMES. THE FLYWEIGHTS WERE NOT LOCATED. NO DETERMINATION COULD BE MADE AS TO THE REASON FOR THE CAP TO SEPARATE FROM THE BODY.
Probable cause
SEPARATION OF THE PROPELLER GOVERNOR COVER FROM THE BODY FOR UNDETERMINED REASONS AND VISUAL RESTRICTION OF THE PILOT DUE TO LEAKING OIL WHICH COVERED THE WINDSCREEN.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MIA92LA139
- Event ID
- 20001211X14938
- Case number
- MIA92LA139
- 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: d95c1d05cf0f122e827ba3253e3a8e088bec68490ba96bd1d250f621aefda816; retrieved 2026-09-23T03:02:19.103Z.