# NTSB FTW97LA310: Waco KNF, Wamsutter, WY, August 15, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 15, 1997, 11:05 local (17:05 UTC) - Place: Wamsutter, WY - Coordinates: 41.660499, -107.969276 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.6605&lon=-107.9693&mi=10 - Phase of flight: [Uncontrolled descent](https://openairdocs.org/ntsb-phases/650) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 2, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 20313 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW97LA310 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20313/pdf - Page: https://openairdocs.org/ntsb/FTW97LA310 ## Probable cause The pilot's failure to maintain directional control during the precautionary landing. A factor was a wind gust. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, descent - uncontrolled - weather condition - downdraft - precautionary landing - performed, pilot in command - Loss of control - on ground/water, landing - roll - weather condition - gusts (contributing factor) - directional control - not maintained, pilot in command (cause) ## Analysis The pilot said he encountered a desert wave and when he could not arrest the descent using full power, he chose to make a precautionary landing on a gravel road. He made a wheel landing but a wind gust caused the airplane to become airborne again. As the airplane settled back to the ground, a wind gust lifted the right wing and pitched the nose down. The airplane collided with a ditch and nosed over. ## Factual narrative On August 15, 1997, approximately 1105 mountain daylight time, a Waco KNF, NC698N, was substantially damaged when it collided with terrain during a precautionary landing near Wamsutter, Wyoming. The commercial pilot, the only occupant aboard, was not injured. Visual meteorological conditions prevailed, and a VFR flight plan had been filed. The flight originated at Rawlins, Wyoming, approximately 1000. In his accident report, the pilot said he was about 5 to 10 miles west of Rawlins when he experienced "a lifting action (desert wave). . .holding (a constant) altitude produced an indicated airspeed of about 10 knots higher than normal and required a power reduction to avoid engine overspeed." As the pilot approached Wamsutter, he encountered "an opposite wind effect. . .(with) full power RPM and holding climb speed resulted in a very slow descent." When the airplane continued descending below 200 feet agl (above ground level), the pilot chose to make a precautionary landing on a gravel road. The pilot made a wheel landing but a wind gust caused the airplane to become airborne again. As the airplane settled back to the ground, "a really weird and severe (wind) gust lifted the right wing beyond any amount of aileron control (clear to the stop) and pitched the plane nose down into a ditch alongside the road)," where it nosed over. Weather documents used by Casper, Wyoming, Flight Service Station (FSS) personnel to brief the pilot were submitted for review. The Rock Springs area forecast (TAF), issued at 1142 and valid for a 24-hour period beginning at 1200, indicated the wind would be from 270 degrees at 25 knots, with gusts to 37 knots. The Rawlins area forecast, covering the same time period, indicated the wind would be from 230 degrees at 22 knots, with gusts to 32 knots. AIRMET (Airman's Meteorological Information) Tango update 2, issued at 0745 and valid until 1400, predicted occasional moderate turbulence below FL (flight level) 180 (18,000 feet) due to moderate northwesterly winds. The airplane's true indicated airspeed, as filed by the pilot on his VFR flight plan, was 65 knots. ## Aircraft - Registration: NC698N (not matched to a registry record) - Reported make and model: Waco KNF - Category: Airplane - Serial number: 3246 - Engines: Kinner K-5 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: William C. Phelps - Airworthiness certificate: Standard, Normal - Departed: RWL, RAWLINS, WY - Destination: RKS, ROCK SPRINGS, WY - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: rear; flight hours: 7,780 total, 104 in this make and model, 5,541 as pilot in command, 68 in the last 90 days, 68 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 27 knots, gusting 38 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 39 °F - Altimeter: 29.00 inHg - Observed at: RKS, 49 nm away 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.