# NTSB CHI89LA141: Cessna R172K, N736DA, Wisconsin Dells, WI, July 22, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 22, 1989, 12:15 local (17:15 UTC)
- Place: Wisconsin Dells, WI
- Coordinates: 43.620567, -89.770683 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.6206&lon=-89.7707&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report July 9, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 14386
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI89LA141
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14386/pdf
- Page: https://openairdocs.org/ntsb/CHI89LA141

## Probable cause

FAILURE OF THE PILOT TO INSURE THE OIL FILLER CAP WAS PROPERLY SECURED WHEN HE SERVICED THE AIRCRAFT BEFORE TAKEOFF, AND SUBSEQUENT LOSS OF OIL AND OIL EXHAUSTION.  THE TREE WAS CONSIDERED TO BE A CONTRIBUTING FACTOR.

## 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 - normal
  - lubricating system,oil filler cap - loose (cause)
  - aircraft service - improper, pilot in command (cause)
  - fluid,oil - leak (cause)
  - fluid,oil - exhaustion (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - object - tree(s) (contributing factor)

## Analysis

WHILE EN ROUTE, THE PLT HEARD A 'MUFFLED POP' FROM THE ENG. APRX 30 SEC LATER, HE NOTICED SMOKE ENTERING THE COCKPIT & SOME POWER LOSS. OIL PRESSURE WAS OBSERVED GOING TO ZERO. THE PLT SHUT OFF THE FUEL & MADE AN EMERG LANDING. DRG THE LANDING, THE LEFT WING STRUCK A TREE & THE ACFT WAS DAMAGED. A POST-ACDNT INSPN REVEALED THE OIL FILLER CAP WAS LOOSE & HANGING FROM ITS CHAIN. A TEARDOWN INSPN OF THE ENG REVEALED NO EVIDENCE OF MECHANICAL DEFECTS WHICH WOULD HAVE ACCOUNTED FOR THE OIL LOSS.

## Aircraft

- Registration: [N736DA](https://openairdocs.org/deregistered/N736DA-1990-12-03), registration cancelled 1990-12-03, S/N R1722434 (OpenAirDocs)
- Reported make and model: CESSNA R172K
- Registry model: [Cessna R172K](https://openairdocs.org/model/cessna-r172k) (registry code 2072431) (OpenAirDocs)
- Category: Airplane
- Serial number: R1722434
- Airframe hours: 1938
- Engines: CONTINENTAL IO-360-K 195 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Robert B. Toenjes
- Registered owner: Robert B Toenses
- Last inspection: Annual, July 17, 1989, 2 hours before
- Departed: C25, WAVERLY, IA
- Destination: FLD, FOND DU LAC, WI

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 59; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 154 total, 69 in this make and model, 154 as pilot in command, 4 in the last 90 days, 4 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 60° at 10 knots
- Visibility: 5 statute miles
- Lowest ceiling: 2,200 ft overcast
- Temperature: -0 °F, dew point -0 °F
- Altimeter: 30.00 inHg

## 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 19890722024769A](https://openairdocs.org/incident/19890722024769A), Jul 22, 1989: Cessna R172K, Wisconsin Dells, WI, Substantial damage. Lost oil pressure en route. On forced landing hit a tree. Oil cap off.

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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