CHI04FA203 · Knoepflein Lancair Legacy 2000
Knoepflein Lancair Legacy 2000 · Accident: total loss of engine power (mechanical failure) en route
From Wittman Regional Airport (OSH) to Lebanon Springfield Airport - George Hoerter Field (6I2)
Event
- NTSB case
- CHI04FA203
- 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
- 1 · 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
Knoepflein Lancair Legacy 2000
- Aircraft type
- Knoepflein LANCAIR LEGACY 2000
- 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
- N98SN
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Wittman Regional Airport (OSH), Oshkosh, WITo Lebanon Springfield Airport - George Hoerter Field (6I2), Lebanon, KY
- 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
- Total loss of engine power (mechanical failure)
- 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
- Pole
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Engine assembly, cylinder › Overtemperature
- Engine assembly, piston › Failure, total
- Pilot in command › Clearance, not maintained
- Pilot in command › In-flight planning/decision, poor
- Pilot in command › Operation with known deficiencies in equipment, continued
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The amateur-built airplane was destroyed when it impacted a light pole and terrain during an off airport landing following a loss of engine power. The airplane was at an altitude of 8,000 feet mean sea level (msl), 15 miles southeast of the airport, when the pilot informed air traffic control (ATC) that he was having an engine problem and he needed to land. The controller cleared the airplane to land on either runway 32 or runway 21. The pilot told the controller, "Alright uh if you don't mind I'm going to circle around up here and uh see if I can iron out the problem and then uh I'll try to let you know what I need to do." Two minutes later, the controller informed the pilot that he was now eight miles from the airport. The pilot responded that he had the airport in site. The controller informed the pilot that runway 32 was the closest runway to his present position to which the pilot responded that he would enter a left base for runway 21. Nineteen seconds later, the pilot reported he was "really having problems" and he was going to land on runway 32. The pilot then stated that he was losing altitude "really bad" and he did not think he was going to make it to the airport. The airplane contacted a light pole and the terrain along a 4-lane divided roadway. The pilot was also the aircraft builder. He installed a supercharger system on the Continental IO-550 engine. Acquaintances of the pilot reported he told them he was experiencing problems with high oil temperatures and high cylinder head temperatures on the number one and number three cylinders. One acquaintance stated the pilot mentioned the problem approximately 10 months prior to the accident and others stated the pilot talked about the continuing problem on the day prior to the accident. Post accident inspection of the engine revealed a hole in the top of the engine case near the number two cylinder. An engine teardown revealed the engine had suffered internal heat and impact damage. Metal debris was found throughout the engine. All of the pistons and cylinders sustained heat and/or impact damage. The number three piston head was burned through along an approximate 60 degree arc around the circumference and down the side of the head past the rings The piston head was black in color. The piston rings were distorted and were out of their grooves. The airplane was equipped with an electronic flight instrument system (EFIS). The EFIS data showed the engine oil pressure was at its maximum of 69 pounds per square inch (psi) prior to takeoff and it decreased throughout the flight as the oil temperature increased. The data also indicated that after the pilot informed ATC of the engine problem, the airplane's rate of descent varied between 100 and 4,000 feet per minute.
Probable cause
A loss of engine power due to high engine temperatures which resulted in a failure of the number three piston, the pilot's continued operation of the airplane with known high temperature problems, the pilot's poor inflight planning, and the pilot's failure to maintain a proper emergency descent rate. A factor associated with the accident was the light pole that the airplane contacted.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI04FA203
- Event ID
- 20040804X01144
- Case number
- CHI04FA203
- 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: 641fd1febf14d57ec07536cdaba2b494dec6f1dcef64454c74924b0112484c46; retrieved 2026-09-20T18:24:00.287Z.