# NTSB DEN85LA024: Cessna 185C, N5831T, Williston, ND, November 8, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: November 8, 1984, 10:45 local (16:45 UTC)
- Place: Williston, ND
- Coordinates: 48.159801, -103.629402 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.1598&lon=-103.6294&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16599
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN85LA024
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16599/pdf
- Page: https://openairdocs.org/ntsb/DEN85LA024

## Analysis

THE ACFT COLLIDED WITH A BRIDGE DURING AN ABORTED TAKEOFF AFTER FAILING TO GET AIRBORNE. THE PLT ABORTED THE TAKEOFF BUTTHE ACFT FAILED TO STOP IN TIME TO AVOID A COLLISION WITH A RAILROAD BRIDGE ABUTMENT MADE OF CONCRETE. THE PLT STATED THAT THE ACFT HAD BEEN SUBJECTED TO SUB-FREEZING TEMPS WITH WATER INSIDE THE PONTOONS. THE SWELLING FROM THE FREEZING WATER (ICE) COMPROMISED THE FLOATS WHICH DEVELOPED LEAKS OF SEVERE NATURE; ENOUGH TO ALLOW THE ACFT TO SINK IN AN EST TWO HOURS. THE REASON THE ACFT DID NOT SINK WHEN LEFT UNATTENTED FOR 2 WKS WAS BECAUSE IT WAS AGROUND. WHEN THE PLT PUMPED THE WATER (NO ICE INSIDE ACCORDING TO HIM) OUT AND LAUNCHED THE ACFT HE MADE NO FURTHER PRE-FLT CHECKS BUT IMMEDIATELY STARTED A TAKEOFF TAXI.

## Sequence of events

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

- In flight collision with object, takeoff - initial climb
  - landing gear,float assembly - buckled (contributing factor)
  - landing gear,float assembly - leak (contributing factor)
  - landing gear,float assembly - previous damage (contributing factor)
  - aircraft preflight - inadequate, pilot in command (cause)
  - judgment - poor, pilot in command (cause)
  - aborted takeoff - delayed, pilot in command (cause)
- In flight collision with terrain/water, takeoff - initial climb

## Aircraft

- Registration: [N5831T](https://openairdocs.org/deregistered/N5831T-2021-12-04), registration cancelled 2021-12-04, S/N 185-0731, built 1964 (OpenAirDocs)
- Reported make and model: CESSNA 185C
- Registry model: [Cessna 185C](https://openairdocs.org/model/cessna-185c) (registry code 2072808) (OpenAirDocs)
- Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 1850731
- Airframe hours: 4000
- Engines: CONTINENTAL IO-470-F 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Rocjard Ziesmer
- Airworthiness certificate: Standard, Normal
- Destination: GREAT FALLS, MT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 27; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 1,614 total, 1,396 in this make and model, 1,494 as pilot in command, 34 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 20° at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: 600 ft overcast
- Temperature: 28 °F, dew point 25 °F
- Altimeter: 29.00 inHg
- Observed at: ISN, 2 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 19841108074379A](https://openairdocs.org/incident/19841108074379A), Nov 8, 1984: Cessna 185, Williston, ND, Substantial damage. Tried takeoff, no clearance with control zone IFR. Would not fly. Water in floats. Aborted, hit bridge piling, sank

## Other investigations on N5831T (1)

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

- [NTSB FTW67F0617](https://openairdocs.org/ntsb/FTW67F0617), May 18, 1967: Cessna 185C (N5831T), Houma, LA, substantial damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; 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.