# NTSB CHI91LA215: Cessna 182A, N4735D, Menomonee Falls, WI, July 5, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 5, 1991, 18:15 local (23:15 UTC)
- Place: Menomonee Falls, WI
- Coordinates: 43.140758, -88.120971 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.1408&lon=-88.1210&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report March 10, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 15118
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI91LA215
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15118/pdf
- Page: https://openairdocs.org/ntsb/CHI91LA215

## Probable cause

THE FATIGUE INDUCED PROPELLER BLADE FAILURE. A RELATED FACTOR WAS THE OPERATOR'S DELAYED PROPELLER OVERHAUL.

## Sequence of events

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

- Airframe/component/system failure/malfunction, takeoff - roll/run
  - propeller system/accessories,blade - fatigue (cause)
  - propeller system/accessories,blade - failure,total
  - maintenance,overhaul - delayed, company/operator management (contributing factor)

## Analysis

SHORTLY AFTER THE PILOT APPLIED FULL POWER FOR THE TAKEOFF GROUND ROLL, ONE PROPELLER BLADE FAILED AND SEPARATED FROM THE HUB ASSEMBLY.  THE ENGINE THEN BROKE FREE OF THE ENGINE MOUNTS.  POST ACCIDENT METALLURGICAL EXAMINATION OF THE PROPELLER BLADE AND HUB ASSEMBLY REVEALED THE FAILURE WAS DUE TO FATIGUE.  THE POINT OF ORIGIN WAS THE FIRST THREAD OF THE THREADED HUB.  THE PROPELLER HAD BEEN INSTALLED ON JULY 11, 1975, AND HAD ACCUMULATED 1227.57 HOURS AT THE TIME OF THE ACCIDENT.  THE PROPELLER HAD NOT BEEN OVERHAULED.  THE MANUFACTURER RECOMMENDS PROPELLER OVERHAUL AT INTERVALS NOT TO EXCEED 5 CALENDAR YEARS.  AN AIRWORTHINESS DIRECTIVE EFFECTIVE 33 DAYS AFTER THE ACCIDENT REQUIRES A PENETRANT INSPECTION OF THE PROPELLER  BLADE THREADED RETENTION AREA, AND A MODIFICATION OF THE PROPELLER ASSEMBLY FOR EARLY DETECTION OF FAILURE.

## Aircraft

- Registration: [N4735D](https://openairdocs.org/deregistered/N4735D-2014-10-14), registration cancelled 2014-10-14, S/N 34835, built 1957 (OpenAirDocs)
- Reported make and model: CESSNA 182A
- Registry model: [Cessna 182A](https://openairdocs.org/model/cessna-182a) (registry code 2072704) (OpenAirDocs)
- Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 34835
- Airframe hours: 4200
- Engines: CONTINENTAL O-470-L 235 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Robert D. Blanchard
- Registered owner: Robert D. Blanchard
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 2, 1991, 90 hours before
- Airport: 76C, Aeropark, runway 18, 2,600 × 50 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 668 total, 520 in this make and model, 628 as pilot in command, 19 in the last 90 days, 9 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 15 statute miles
- Lowest ceiling: none

## 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 19910705026539A](https://openairdocs.org/incident/19910705026539A), Jul 5, 1991: Cessna 182A, Menomonee Falls, WI, Substantial damage. Prop blade separated on takeoff roll. Vibration separated engine. Stopped safely. AD issued post accident on prop

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.

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