# NTSB WPR16LA135: Bert N Norris RV-6, N916BN, St. Maries, ID, July 4, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 4, 2016, 09:30 local (16:30 UTC) - Place: St. Maries, ID - Coordinates: 47.323333, -116.569168 - Nearby events: https://openairdocs.org/map.md?lat=47.3233&lon=-116.5692&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Fuel related](https://openairdocs.org/ntsb-events/190) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report October 17, 2017 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 93523 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR16LA135 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93523/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93523 - Page: https://openairdocs.org/ntsb/WPR16LA135 ## Probable cause A partial loss of engine power due to carburetor icing, which resulted from the pilot’s failure to apply carburetor heat. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ice/rain protection system: intake anti-ice, deice](https://openairdocs.org/ntsb-findings/01023020): Aircraft › Aircraft systems · Not used/operated (probable cause); cases with it: [Norris Bert N RV-6, 1 case](https://openairdocs.org/ntsb-findings/01023020/cases.md?model=05602W5), [All aircraft, 108 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Norris Bert N RV-6, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=05602W5), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Norris Bert N RV-6, 1 case](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=05602W5), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Norris Bert N RV-6, 1 case](https://openairdocs.org/ntsb-events/190/sequence.md?model=05602W5), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Norris Bert N RV-6, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05602W5), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Norris Bert N RV-6, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=05602W5), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The private pilot reported that, on short final to the runway, the engine lost partial power. The pilot then switched fuel tanks, activated the boost pump, and pumped the throttle, but engine power was not restored. The pilot subsequently landed in a field about 300 to 500 ft short of the runway, and the airplane nosed over. Postaccident examination of the airplane and engine revealed no mechanical anomalies that would have precluded normal operation. The pilot stated that he believed that the loss of power was due to carburetor ice because he might not have applied carburetor heat during the flight. The weather conditions at the time of the accident were conducive to moderate carburetor icing at cruise power settings and serious carburetor icing at descent power settings. It is likely that the loss of engine power resulted from carburetor icing due to the pilot's failure to apply carburetor heat. ## Factual narrative On July 4, 2016, about 0930 Pacific daylight time, a Bert N. Norris RV-6, experimental amateur-built conventional gear airplane, was substantially damaged during a forced landing following a loss of engine power near St. Maries Municipal Airport (S72), St. Maries, Idaho. The airplane was registered to a private individual and operated by the pilot as a 14 Code of Federal Regulations Part 91 personal flight. The private pilot and one passenger were not injured. Visual meteorological conditions (VMC) prevailed and a flight plan was not filed. The flight originated from Homeport Airport (11WA), Cheney, Washington, about 0910.During a telephone interview with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on the day following the accident, the pilot stated that while on short final approach to runway 28 at S72, the engine experienced a partial loss of power. He believed the power loss was due to carburetor icing, as he may not have activated the carburetor heat. He then switched fuel tanks, activated the boost pump, pumped the throttle, but was unable to restore power. The pilot reported that he subsequently landed the airplane in a field about 100 yards from the approach end of runway 28. during the landing roll, the airplane nosed over, which resulted in substantial damage to the rudder. In a written report submitted to the NTSB IIC on July 14, 2016, the pilot reported that as he approached S72 he visually confirmed that the weather was still VMC. He entered the [traffic] pattern for runway 28, began to reduce power on the engine, and while in the turn from base leg to final approach the engine completely quit. The pilot stated that he verified that the carburetor heat and the fuel boost pump were on, after which he changed the fuel selector to the opposite tank. He then looked for a place to land, but most of the fields were filled with hay bales, which prompted him to continue his turn to the airport. The pilot stated that the airplane touched down about 500 ft short of runway 28 and nosed over. The airplane sustained damage to both wings, the rudder and the elevator. According to a Federal Aviation Administration aviation safety inspector who performed an onsite postaccident examination of the airplane, the inspector reported that he was able to rotate the propeller by hand, that the engine appeared to be in good shape, and the examination revealed no general indication of engine failure that would have been causal to the accident. Additionally, the inspector reported that the pilot relayed to him that carburetor heat might not have been applied during the flight, which may have caused the engine to lose power during the approach to the airport. According to a carburetor icing probability chart, the reported temperature and dew point at the time of the accident were in a range for moderate carburetor icing at cruise power settings and serious carburetor icing at descent power settings. ## Aircraft - Registration: [N916BN](https://openairdocs.org/aircraft/N916BN), registered now, S/N 21085, built 1998 (OpenAirDocs) - Reported make and model: BERT N Norris RV-6 - Registry model: [Norris Bert N RV-6](https://openairdocs.org/model/norris-bert-n-rv-6) (registry code 05602W5) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 21085 - Year built: 1998 - Airframe hours: 972.39 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Continuous airworthiness, July 3, 2016, 3 hours before - Departed: 11WA, Cheney, WA - Destination: S72, St. Maries, ID - Airport: S72, St. Maries Municipal Airport, runway 28, 3,354 × 60 ft, asphalt - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review April 17, 2015; seat: left; restraint: 4-point; flight hours: 1,420 total, 1 in this make and model, 1,390 as pilot in command, 30 in the last 90 days, 3 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 11 knots, gusting 16 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 39 °F - Altimeter: 29.97 inHg - Observed at: COE, 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 20160704010659A](https://openairdocs.org/incident/20160704010659A), Jul 4, 2016: Norris Bert N RV-6, St. Maries, ID, Substantial damage. On July 4, 2016, about 0930 pacific daylight time, an RV-6 airplane, was substantially damaged during a forced landing following a loss of engine power at St.… ## Docket (4 files) The files NTSB released with the investigation on August 21, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93523. 3.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455539&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Weather Data (item 2, .PDF, 337 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455540&FileExtension=.PDF&FileName=Weather%20Data-Master.PDF - Record of Conversation - Robert Vietzke (Pilot) (item 3, .PDF, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455541&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Robert%20Vietzke%20(Pilot)-Master.PDF - Record of Report from FAA Inspector (item 4, .PDF, 116 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40455542&FileExtension=.PDF&FileName=Record%20of%20Report%20from%20FAA%20Inspector-Master.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.