CHI05FA049 · Piper PA-23-250
Piper PA-23-250 · Accident: loss of engine power en route
From Menominee–Marinette Twin County Airport (MNM) to Gogebic Iron County Airport (IWD)
Event
- NTSB case
- CHI05FA049
- 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
- 5 · 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
Piper PA-23-250
- Aircraft type
- Piper PA-23
- 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
- N5398M
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Menominee–Marinette Twin County Airport (MNM), Menominee, MITo Gogebic Iron County Airport (IWD), Ironwood, MI
- 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/spin
- 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, cylinder › Fatigue
- Engine assembly, cylinder › Fractured
- Pilot in command › Aircraft control, not maintained
- Pilot in command › Airspeed(vmc), not maintained
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The twin-engine airplane was substantially damaged during an in-flight collision with terrain following a loss of control in the airport traffic pattern. Approximately 20 minutes prior to the accident the pilot transmitted: "I've got single engine problems here mayday mayday." Radar track data depicted the aircraft established on a northwest course at 3,500 feet mean sea level. At the time the pilot reported the engine failure, track data showed the aircraft entered a descending left turn, losing 1,000 feet and reaching a south heading 24 seconds later. The pilot regained control of the aircraft and air traffic control provided guidance to the destination airport, which was the nearest airport. The pilot subsequently established the aircraft on approach to the airport. The pilot stated that he was going to circle the airport to the left and hand pump the gear down. The aircraft impacted terrain approximately one-quarter mile south of the runway in the side yard of a residence. The residence was located adjacent to airport property. A line of trees about 40 feet in height was located approximately 19 feet west of the accident site. No evidence of a tree strike was observed. The airplane came to rest resting on the nose and the wings. The empennage was oriented vertically, approximately 65 degrees relative to the terrain. The landing gear was extended. Examination of the left engine revealed a separation of the No. 4 cylinder head. The cylinder head had separated between the second and third cooling fin. Metallurgical examination revealed that the fracture was consistent fatigue cracking. Examination of the left propeller and propeller governor did not reveal any anomalies preventing normal operation of the feathering mechanism. Observations during the left propeller teardown were consistent with the propeller not being in the feathered position at the time of the accident. Maintenance records indicated that approximately 345 hours had accumulated on both engines since overhaul. No other anomalies were observed. According to the aircraft manufacturer's documentation, the accident aircraft hydraulic system was powered by one engine-driven hydraulic pump mounted on the left engine. Hydraulic pressure was used to control the retractable landing gear and the flaps. In the event the left engine loses power the hydraulic pump is not powered and emergency gear extension must be used.
Probable cause
Fatigue fracture of an engine cylinder resulting in a loss of power on the left engine. Additional causes were the pilot's failure to maintain minimum control airspeed (Vmc), the resulting loss of aircraft control, and an inadvertent stall/spin. Contributing factors were the pilot's failure to feather the propeller on the failed engine and his decision to turn toward the inoperative engine during the circling maneuver. Additional factors were the inoperative hydraulic system pump and the emergency landing gear actuation which caused the pilot to circle prior to landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI05FA049
- Event ID
- 20050104X00012
- Case number
- CHI05FA049
- 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: a13ceb64bac1d3356366266f4360e89e576e911b4f0cb5849ab6f6a1ded44be2; retrieved 2026-09-20T18:10:13.356Z.