# NTSB CHI92LA015: North American Navion D, N10JF, Lake Geneva, WI, October 20, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 20, 1991, 16:00 local (21:00 UTC)
- Place: Lake Geneva, WI
- Coordinates: 42.579452, -88.419349 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.5795&lon=-88.4193&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report August 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 15339
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI92LA015
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15339/pdf
- Page: https://openairdocs.org/ntsb/CHI92LA015

## Probable cause

FATIGUE FAILURE OF THE CRANKSHAFT.  A FACTOR IN THE ACCIDENT WAS INADEQUATE QUALITY CONTROL BY OTHER MAINTENANCE PERSONNEL.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - mech failure/malf, cruise
  - engine assembly,crankshaft - fatigue (cause)
  - maintenance,overhaul,major
  - inadequate quality control, other maintenance personnel (contributing factor)
- Gear collapsed, descent - emergency
  - terrain condition - rough/uneven

## Analysis

THE PILOT CLIMBED TO CRUISE ALTITUDE AND HAD SET POWER BEFORE THE ENGINE VIBRATED BRIEFLY AND QUIT.  THE PILOT EXECUTED A FORCED LANDING IN A ROUGH FIELD.  ENGINE TEARDOWN REVEALED A BROKEN CRANKSHAFT.  THE FRACTURE SURFACE SHOWED FATIGUE EMANATING FROM A SCRATCH IN A FILLET AT THE NUMBER 2 MAIN BEARING JOURNAL.

## Aircraft

- Registration: [N10JF](https://openairdocs.org/aircraft/N10JF), registered now, S/N NAV-4-1391 (OpenAirDocs)
- Reported make and model: NORTH AMERICAN NAVION D
- Registry model: [North American NAVION D](https://openairdocs.org/model/north-american-navion-d) (registry code 6150142) (OpenAirDocs)
- Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: NAV-4-1391
- Airframe hours: 5200
- Engines: CONTINENTAL I0-520B 285 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Rempert, Roger L.
- Registered owner: Rempert, Roger L.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 5, 1991, 95 hours before
- Departed: C59, DELAVAN, WI
- Destination: ENW, KENOSHA, WI
- Airport: C02, Americana, runway 23, 4,100 × 75 ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 1,500 total, 500 in this make and model, 1,500 as pilot in command, 100 in the last 90 days, 25 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 230° at 14 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Altimeter: 30.00 inHg
- Observed at: JVL, 29 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19911020047079A](https://openairdocs.org/incident/19911020047079A), Oct 20, 1991: Tmpson NAVIOND, Lake Geneva, WI, Substantial damage. Lost power,collapsed right gear on forced landing. Crankshaft had broken due to fatigue cracks.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.