# NTSB CHI99LA297: Weatherly 201B, N197SK, Oberlin, KS, August 8, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 8, 1999, 07:45 local (12:45 UTC) - Place: Oberlin, KS - Coordinates: 39.820407, -100.529548 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.8204&lon=-100.5295&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 18, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 47072 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI99LA297 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47072/pdf - Page: https://openairdocs.org/ntsb/CHI99LA297 ## Probable cause Engine failure due to an undertorqued carburetor fulcrum screw. Contributing factors were the muddy terrain and the low altitude of the aerial operation. ## 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, maneuvering - aerial application - fuel system,carburetor float - undertorqued (cause) - In flight collision with terrain/water, emergency landing - terrain condition - muddy (contributing factor) - altitude - low (contributing factor) ## Analysis The airplane impacted a muddy field following a loss of engine power during an aerial application. The Bendix NA-R9B carburetor fulcrum screw and the carburetor float pivot pin exhibited chatter marks. The fulcrum screw was removed after turning it 1/2 of a turn. The fulcrum screw safety wire was broken. The NA-R9B float carburetor technical overhaul manual states that the fulcrum screw is to be torqued to a value of 100-120 in-lbs. ## Factual narrative On August 8, 1999, at 0745 central daylight time, a Weatherly 201B, N197SK, operated and piloted by a commercial pilot, impacted a muddy field following a loss of engine power during an aerial application of a field, located approximately 3 miles west and 1-1/4 miles south of Oberlin, Kansas. Instrument meteorological conditions prevailed at the time of the accident. The 14 CFR Part 137 agricultural flight was not operating on a flight plan. The pilot sustained no injuries. The flight departed the pilot's private airport at 0700. The pilot stated that he was 100 feet agl "coming out of a 180 degree turn when the engine abruptly lost power. He was working a field from east to west. The oil and fuel pressure was "ok". The engine was barely running and he could not bring the power back up. He did not "pull" the carburetor heat during the loss of engine power. He stated that he did not have a choice of where to land as the engine stopped. During the landing, the main landing gear separated from the aircraft and its belly became shredded. Inspection of the airplane by the Federal Aviation Administration revealed that there was 28 gallons of fuel aboard. The Bendix NA-R9B carburetor fulcrum screw and the carburetor float pivot pin exhibited chatter marks. The fulcrum screw was removed after turning it 1/2 of a turn. The fulcrum screw safety wire was broken. The NA-R9B float carburetor technical overhaul manual states that the fulcrum screw is to be torqued to a value of 100-120 in-lbs. ## Aircraft - Registration: [N197SK](https://openairdocs.org/aircraft/N197SK), registered now, S/N 1645 (OpenAirDocs) - Reported make and model: Weatherly 201B - Registry model: [Weatherly 620B](https://openairdocs.org/model/weatherly-620b) (registry code 9630605) (OpenAirDocs) - Category: Airplane - Serial number: 1645 - Airframe hours: 847 - Engines: P&W R-985 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Richard E Shaw - Registered owner: Richard E Shaw Incorporated - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, February 5, 1999, 605 hours before - Departed: KS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 6,742 total, 536 in this make and model ## Weather - Conditions: Instrument (IMC), Day - Wind: 240° at 4 knots - Visibility: 6 statute miles - Lowest ceiling: 100 ft broken - Temperature: 64 °F, dew point 64 °F - Altimeter: 30.00 inHg - Observed at: MCK, 28 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 19990808026749A](https://openairdocs.org/incident/19990808026749A), Aug 8, 1999: Wthrly 620B, Oberlin, KS, Substantial damage. (.19) On August 8, 1999, at 0745 central daylight time, a weatherly 201B, operated and piloted by a commercial pilot impacted terrain following a partial loss… 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.