# NTSB MKC85LA071: Cessna 152, N67399, Norwalk, IA, March 14, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 14, 1985, 11:09 local (17:09 UTC)
- Place: Norwalk, IA
- Coordinates: 41.489009, -93.680313 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.4890&lon=-93.6803&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 33920
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC85LA071
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/33920/pdf
- Page: https://openairdocs.org/ntsb/MKC85LA071

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, cruise - normal
  - accessory drive assy,drive gear - fatigue (cause)
  - accessory drive assy,drive gear - failure,total (cause)
  - maintenance,overhaul - inadequate, other maintenance personnel (cause)
- Forced landing, cruise - normal
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - ground (contributing factor)
  - terrain condition - soft (contributing factor)

## Analysis

APPROACHING DES MOINES AIRPORT THE PLT RPTD TO APPROACH CONTROL OF ENG PROBLEMS AND WANTED TO KNOW WHAT AIRPORT WAS CLOSE FOR AN PRECAUTIONARY LANDING. AN ATTEMPT WAS MADE TO LAND AT AN AIRSTRIP 3 MI EAST OF HIS PRESENT POSN. UNABLE TO LAND AT THE AIRSTRIP THE ACFT MADE A LANDING TO A FIELD WHERE IT SUSTAINED SUBSTANTIAL DAMAGE. INSPECTION OF THE ENG REVEALED A BROKEN CRANKSHAFT IDLER GEAR. FATIGUE PROGRESSION WAS EVIDENT ON THE FRACTURE SURFACES EXAMINED. ALSO NOTED WAS AN ELLIPTICAL DEFORMATION OF THE THREADED PORTION OF THE RETAINING BOLT BELOW THE BOLT HEAD. THIS DEFORMATION WAS OF THE SAME THICKNESS AS THE BOLTFLANGE AND LOCKNUT PLATE. VISUAL INSPECTION OF THE FRACTURE SURFACES GAVE NO EVIDENCE OF UNUSUAL CONTACT OR WEAR PATTERN PRIOR TO FAILURE.

## Aircraft

- Registration: [N67399](https://openairdocs.org/deregistered/N67399-1991-03-28), registration cancelled 1991-03-28, S/N 15281815 (OpenAirDocs)
- Reported make and model: CESSNA 152
- Registry model: [Cessna 152](https://openairdocs.org/model/cessna-152) (registry code 2071835) (OpenAirDocs)
- Category: Airplane
- Serial number: 15281815
- Airframe hours: 2773
- Engines: LYCOMING O-235 L2C 110 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Registered owner: Proflight, Inc.
- Airworthiness certificate: Standard, Normal
- Departed: MLE, OMAHA, NE
- Destination: DSM, DES MOINES, IA
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 25; student; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 43 total, 43 in this make and model, 17 as pilot in command, 17 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 17 knots, gusting 22
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 45 °F, dew point 30 °F
- Altimeter: 30.00 inHg
- Observed at: DSM, 6 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 19850314006889A](https://openairdocs.org/incident/19850314006889A), Mar 14, 1985: Cessna 152, Norwalk, IA, Substantial damage. Crankshaft idler gear failed, resulting in an engine power loss. Pilot made an emergency landing in a muddy field.

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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