# NTSB CEN11LA541: Weatherly 620B, N90181, Hettinger, ND, July 30, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 30, 2011, 10:00 local (15:00 UTC) - Place: Hettinger, ND - Coordinates: 46.015556, -102.655555 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.0156&lon=-102.6556&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 27, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 81378 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA541 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81378/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81378 - Page: https://openairdocs.org/ntsb/CEN11LA541 ## Probable cause Internal failure of the engine for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Weatherly 620B, 1 case](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=9630605), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Weatherly 620B, 2 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=9630605), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Weatherly 620B, 2 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=9630605), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Weatherly 620B, 9 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=9630605), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The agricultural airplane was maneuvering at 500 feet above ground level when the engine lost power, and oil immediately covered the windscreen. During the forced landing, the airplane impacted a dirt berm and came to rest in a ditch. A postaccident examination of the engine showed a hole in the side of the No. 5 cylinder, which is located at the bottom of the engine. The examination also revealed that several of the connecting rods, including the No. 5 master rod, were broken. There was no evidence in the engine of scoring, thermal damage, or oil starvation. Due to the extent of the engine damage, the initial failure mode could not be determined. At the time of the accident, the engine had accumulated 43 hours since major overhaul. ## Factual narrative On July 30, 2011, approximately 1000 central daylight time, a Weatherly Aviation Company 620B single-engine airplane, N90181, sustained substantial damage following a loss of engine power while maneuvering near Hettinger, North Dakota. The commercial pilot was not injured. The airplane was registered to and operated by Air Dakota Flite, Hettinger, North Dakota. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 137 aerial application flight. The local flight departed approximately 0950. According to the pilot, while maneuvering at 500 feet above ground level, the engine lost power and oil immediately covered the windscreen. The pilot initiated a forced landing to a road. During the forced landing, the main landing gear collied with a dirt berm on the side of the road, and the airplane entered a ditch. The airplane came to rest upright and the pilot exited the airplane. An examination of the airplane showed the firewall was damaged. A review of the airplane's maintenance records revealed the Pratt & Whitney R-985 AN-14B radial engine (serial number 13084) underwent its most recent annual inspection on July 5, 2011, at a total time of 5,274 hours, and 15.4 hours since major overhaul. At the time of the accident, the engine had accumulated 43 hours since major overhaul. According to the Federal Aviation Administration (FAA) inspector who responded to the accident site, the airplane was involved in an accident in 2009. During that accident, the engine separated from the airframe. After that accident, the engine received a major overhaul that was completed on December 29, 2009. There is no record in the NTSB database regarding an accident involving N90181 in 2009. On October 18, 2011, the engine was examined and disassembled at the facilities of Tulsa Aircraft Engines, Tulsa, Oklahoma, under the supervision of two FAA inspectors. Examination of the engine showed a hole in the side of the number 5 cylinder, which is located at the bottom of the engine. The examination also revealed that several of the connecting rods, including the master rod were broken. The number 5 cylinder is the engine's master rod cylinder. Additionally, there was no evidence in the engine of scoring, thermal damage, or oil starvation. Due to the damage in the engine, the initial failure mode could not be determined. ## Aircraft - Registration: [N90181](https://openairdocs.org/aircraft/N90181), registered now, S/N 1613, built 1996 (OpenAirDocs) - Reported make and model: WEATHERLY AVIATION CO INC 620B - Registry model: [Weatherly 620B](https://openairdocs.org/model/weatherly-620b) (registry code 9630605) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 1613 - Airframe hours: 1315 - Engines: Pratt & Whitney R-985-AN-14B 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Air Dakota Flite - Registered owner: Air Dakota Flite - Airworthiness certificate: Standard, Utility - Last inspection: Annual, July 5, 2011 - Departed: HEI, Hettinger, ND - Destination: HEI, Hettinger, ND ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review September 15, 2009; seat: front; flight hours: 24,000 total, 1,500 in this make and model, 23,800 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 61 °F - Altimeter: 30.06 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 20110730016639A](https://openairdocs.org/incident/20110730016639A), Jul 30, 2011: Weatherly Aviation Co Inc 620B, Hettinger, ND, Substantial damage. Airacrat involved in arial spray operations when engine top cylinder barrel seperated from the head and caused oil to blow back on windscreeen, forcing pilot… ## Docket (5 files) The files NTSB released with the investigation on January 26, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81378. 1.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 302 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361642&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation - Pilot (item 2, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361644&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot-Master.PDF - FAA Inspector Statement (item 3, .PDF, 247 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361643&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF - FAA Inspector Examination Statement (item 4, .PDF, 49 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361646&FileExtension=.PDF&FileName=FAA%20Inspector%20Examination%20Statement-Redacted.PDF - Excerpts of Maintenance Records (item 5, .PDF, 591 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361647&FileExtension=.PDF&FileName=Excerpts%20of%20Maintenance%20Records-Redacted.PDF 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.