ANC06LA005 · Crisenbery Northman 2+2
Crisenbery Northman 2+2 · Accident: total loss of engine power (mechanical failure) en route
From Nenana, AK to Fairbanks International Airport (PAFA)
Event
- NTSB case
- ANC06LA005
- 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
Crisenbery Northman 2+2
- Aircraft type
- Crisenbery NORTHMAN 2
- 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
- N239PT
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Nenana, AKTo Fairbanks International Airport (PAFA), Fairbanks, AK
- 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
- Tree(s)
- 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
- Fluid, oil › Loss, total
- Lubricating system, oil filter/screen › Cracked
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
In preparation for a cross-country personal flight in an amateur built experimental airplane, the private certificated pilot preheated the engine, conducted a preflight, and started the engine to warm it up. After departure, he leveled the airplane in cruise flight, with an outside ambient temperature of about 12 degrees F. About 15 minutes after takeoff, the engine lost power and the propeller stopped. The pilot attempted to restart the engine, but it would not rotate, and he selected an area of small trees for a forced landing. Following the accident, the pilot said he noticed oil covering the belly of the airplane. The airplane was equipped with a remote oil filter housing which was designed for racing/automotive use, and was mounted on the firewall for ease of servicing. The filter is comprised of a rectangular cast aluminum housing. The center of each half of the housing has a raised horizontal rib along the longest axis of the case that incorporates an oil passage. An examination of the housing revealed a vertical, 1.25 inch crack in the center rib of the upper housing half. The crack was also visible on the inside of the housing in the center of the horizontal oil passage. The inner and outer filter screen rubber gaskets were undamaged. The mechanism for the initiation of the crack was not determined.
Probable cause
A loss of engine power during cruise flight due to a cracked oil filter housing and subsequent loss of engine oil, which resulted in a forced landing in trees.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC06LA005
- Event ID
- 20051024X01711
- Case number
- ANC06LA005
- 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: 248986ad182cb3f8106419bd22b35ccdf1d1e4fdad26fa0ca918c8a5793fe7ec; retrieved 2026-09-22T05:18:02.032Z.