CEN16LA043 · Hickham LANCAIR IV-P
Hickham LANCAIR IV-P · Accident: loss of engine power (total) while maneuvering
From Shawano Municipal Airport (EZS) to Shawano Municipal Airport (EZS)
Event
- NTSB case
- CEN16LA043
- 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
Hickham LANCAIR IV-P
- Aircraft type
- Hickham LANCAIR IV-P
- 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
- N10UU
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Shawano Municipal Airport (EZS), Shawano, WITo Shawano Municipal Airport (EZS), Shawano, WI
- Aircraft age
- About 13 years (built 2002)
- 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
- Maneuvering
- Defining eventThe 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 (total)
- 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
- Aircraft › Aircraft power plant
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While practicing an emergency descent during a dual training flight, the pilot receiving instruction entered the airplane into a steep dive, which resulted in a 0.5-G load factor for about 5 seconds and a transient drop in engine oil pressure of about 15 psi. As the descent continued, engine speed steadily increased beyond the maximum operating limit of 2,700 rpm. While still in the dive, the pilot initiated a left turn with a 3-G load factor, during which the engine oversped to 3,390 rpm. The engine immediately began to run rough, and subsequently experienced a total loss of power. The pilot executed a forced landing to a field with the landing gear and flaps retracted, during which the airplane struck a rock wall and tumbled.
Postaccident examination revealed that 8 teeth on the left magneto distributor drive gear and 16 teeth on the right gear had fractured. No evidence of progressive damage or material anomaly was observed with the distributor drive gear teeth. The nylon gear teeth were most likely damaged by the abnormal shock loads on the gear train during the engine overspeed. The damage to the gear teeth resulted in a dual magneto failure and subsequent loss of engine power.
The flight profile of a low-G pushover to a steep dive, which was accompanied by a drop in engine oil pressure, may have led to the propeller governor not supplying adequate oil pressure to the propeller, which subsequently contributed to the engine overspeed and the failure of the magnetos.
Probable cause
A total loss of engine power due to a dual magneto failure, as a result of an exceedance of the engine’s operating limitations while maneuvering.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN16LA043
- Event ID
- 20151117X83015
- Case number
- CEN16LA043
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: aa0de53b5a5376662456357227f8d95c875a7c755c2df17fa0ab1f879a61268d; retrieved 2026-09-16T02:58:24.926Z.