# NTSB CHI98LA016: Piper PA-18-150, N9691P, Williston, ND, October 11, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 11, 1997, 10:30 local (15:30 UTC) - Place: Williston, ND - Coordinates: 48.160453, -103.630973 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.1605&lon=-103.6310&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 29, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 10767 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI98LA016 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10767/pdf - Page: https://openairdocs.org/ntsb/CHI98LA016 ## Probable cause the pilot's inadequate preflight planning/preparation, and his selection of an unsuitable area for landing. The adverse weather condition (low ceiling) and submerged object were related factors. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - preflight planning/preparation - inadequate, pilot in command (cause) - weather condition - low ceiling (contributing factor) - precautionary landing - performed, pilot in command - On ground/water collision with object, landing - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause) - object - submerged object (contributing factor) ## Analysis The pilot decided to land before reaching his original destination due to deteriorating weather conditions. During a landing on the Missouri River, the airplane's floats contacted an unknown object in the water. The airplane subsequently rolled over and sank in the river. The pilot reported he did not obtain a weather briefing before the flight. ## Factual narrative On October 11, 1997, at 1030 central daylight time, a float equipped Piper PA-18-150, N9691P, operated by a commercial pilot collided with debris and nosed over into the Missouri River while landing on the river 20 miles southwest of Williston, North Dakota. The pilot was not injured. The airplane was substantially damaged. Instrument meteorological conditions prevailed and a flight plan was not filed. The flight originated from Poplar, Montana, with an original destination of Bismark, North Dakota. The pilot reported that he was ferrying the airplane from Alaska to Florida when the accident occurred. The pilot reported that he was following the Missouri River en route to Bismark when he encountered 700 to 900 foot ceilings and visibilities of 3 to 5 miles which eventually deteriorated to 500 to 700 foot ceilings and visibilities of 3 miles. He reported that due to the weather conditions he decided to land in Williston and wait for the weather to improve. The pilot reported that while flying down river from Williston, he noticed a "significant" amount of debris floating in the river with no suitable areas on which to land. He reported that he continued toward Williston and when 20 to 25 miles away, "... I came upon a long straight stretch of river that was suitable for landing and opted to set down here and not continue the flight." The pilot reported that upon landing he added power to maintain the airplane on step so he could taxi to a boat launch area. He reported that as he added power the "... floats impacted something in the water, perhaps a submerged log floating downstream, and the aircraft pitched dramatically nose-down into the water, and yawed to the right toward the shoreline. I stood on the left rudder to attempt to straighten directional control as the plane plowed into the water, and the right float impacted rocks on the shore before I could arrest the directional control." The airplane began sinking at which time the pilot exited the airplane. He reported that as the airplane began to roll over he jumped into the water and began to swim. He reported that he had trouble swimming because he was wearing hip- boots. Once he was able to remove the boots e was able to swim and a bystander helped him to shore. The pilot reported that he did not obtain a weather briefing prior to the flight, but had attempted to contact flight service en route to no avail. ## Aircraft - Registration: [N9691P](https://openairdocs.org/aircraft/N9691P), registered now, S/N 18-7709040 (OpenAirDocs) - Reported make and model: Piper PA-18-150 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Category: Airplane - Serial number: 18-7709040 - Airframe hours: 1517 - Engines: Lycoming O-320-A2B 150 horsepower reciprocating - Damage: Substantial damage - Flight: Ferry, Part 91 - Registered owner: Dennis G. Safranek - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 23, 1997, 61 hours before - Departed: POPLAR, MT - Destination: BISMARK, ND ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; commercial, flight instructor; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 9,000 total, 1,400 in this make and model, 9,000 as pilot in command, 70 in the last 90 days, 35 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: 60° at 4 knots - Visibility: 4 statute miles - Lowest ceiling: 300 ft overcast - Temperature: 50 °F, dew point 50 °F - Altimeter: 29.00 inHg - Observed at: ISN, 20 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 19971011031279A](https://openairdocs.org/incident/19971011031279A), Oct 11, 1997: Williston, ND, Destroyed. Acft landed on the Missouri river due to adverse weather, Williston, ND. (-23) departed poplar, Montana at 0845 for bismarck, ND (aircraft was being ferried to… 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.