# NTSB ANC16CA056: Brian Turner Northern Explorer, N907BT, Chickaloon, AK, August 8, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 7, 2016, 21:00 local (Aug 8, 2016, 05:00 UTC) - Place: Chickaloon, AK - Coordinates: 61.724998, -148.069168 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.7250&lon=-148.0692&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR go-around: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 18, 2017 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA Anchorage FSDO - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 93808 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC16CA056 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93808/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93808 - Page: https://openairdocs.org/ntsb/ANC16CA056 ## Probable cause A partial loss of engine power due to carburetor icing, which resulted from the pilot’s failure to use carburetor heat. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Brian Turner NORTHERN EXPLORER, 1 case](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=05634NZ), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Not used/operated (probable cause); cases with it: [Brian Turner NORTHERN EXPLORER, 1 case](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=05634NZ), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/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: [Brian Turner NORTHERN EXPLORER, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=05634NZ), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR go-around: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Brian Turner NORTHERN EXPLORER, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05634NZ), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Brian Turner NORTHERN EXPLORER, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05634NZ), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Brian Turner NORTHERN EXPLORER, 2 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=05634NZ), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that he was conducting a low reconnaissance in his tailwheel-equipped airplane of a potential grass landing site in remote mountainous terrain during the late evening hours. While conducting the low reconnaissance, he engaged the carburetor heat, descended over the landing site, disengaged the carburetor heat, applied full throttle, and then departed from the landing site. As the airplane departed from the landing site, he reported that the engine revolutions per minute (rpm) were "very low" due to carburetor ice. He stated that due to the loss of power the airplane was capable of level flight, but unable to climb. As the airplane approached rising terrain, he turned about 180 degrees, and landed in an area of thick vegetation about 20 miles per hour. During the landing sequence, the propeller and left wing impacted terrain. The airplane sustained substantial damage to both wings and the fuselage. The pilot further reported that the airplane did not have a carburetor temperature gauge installed. The pilot verified that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. In the recommendation section of the National Transportation Safety Board Accident/Incident Reporting Form 6120.1, the pilot stated that the accident may have been avoided if he did not utilize the landing site at that time of the day. The Federal Aviation Administration has published Special Airworthiness Information Bulletin CE-09-35 Carburetor Icing Prevention (2009). This document discusses carburetor icing and states in part: Pilots should be aware that carburetor icing doesn't just occur in freezing conditions, it can occur at temperatures well above freezing temperatures when there is visible moisture or high humidity. Icing can occur in the carburetor at temperatures above freezing because vaporization of fuel, combined with the expansion of air as it flows through the carburetor, (Venturi Effect) causes sudden cooling, sometimes by a significant amount within a fraction of a second. Carburetor ice can be detected by a drop in rpm in fixed pitch propeller airplanes and a drop in manifold pressure in constant speed propeller airplanes. In both types, usually there will be a roughness in engine operation. The pilot should respond to carburetor icing by applying full carburetor heat immediately. The engine may run rough initially for a short time while ice melts. ## Factual narrative The pilot reported that he was conducting a low reconnaissance in his tailwheel-equipped airplane of a potential grass landing site in remote mountainous terrain during the late evening hours. While conducting the low reconnaissance, he engaged the carburetor heat, descended over the landing site, disengaged the carburetor heat, applied full throttle, and then departed from the landing site. As the airplane departed from the landing site, he reported that the engine revolutions per minute (rpm) were "very low" due to carburetor ice. He stated that due to the loss of power the airplane was capable of level flight, but unable to climb. As the airplane approached rising terrain, he turned about 180 degrees, and landed in an area of thick vegetation about 20 miles per hour. During the landing sequence, the propeller and left wing impacted terrain. The airplane sustained substantial damage to both wings and the fuselage. The pilot further reported that the airplane did not have a carburetor temperature gauge installed. The pilot verified that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. In the recommendation section of the National Transportation Safety Board Accident/Incident Reporting Form 6120.1, the pilot stated that the accident may have been avoided if he did not utilize the landing site at that time of the day. The Federal Aviation Administration has published Special Airworthiness Information Bulletin CE-09-35 Carburetor Icing Prevention (2009). This document discusses carburetor icing and states in part: Pilots should be aware that carburetor icing doesn't just occur in freezing conditions, it can occur at temperatures well above freezing temperatures when there is visible moisture or high humidity. Icing can occur in the carburetor at temperatures above freezing because vaporization of fuel, combined with the expansion of air as it flows through the carburetor, (Venturi Effect) causes sudden cooling, sometimes by a significant amount within a fraction of a second. Carburetor ice can be detected by a drop in rpm in fixed pitch propeller airplanes and a drop in manifold pressure in constant speed propeller airplanes. In both types, usually there will be a roughness in engine operation. The pilot should respond to carburetor icing by applying full carburetor heat immediately. The engine may run rough initially for a short time while ice melts. ## Aircraft - Registration: [N907BT](https://openairdocs.org/aircraft/N907BT), registered now, S/N 072515, built 2015 (OpenAirDocs) - Reported make and model: BRIAN TURNER NORTHERN EXPLORER - Registry model: [Brian Turner NORTHERN EXPLORER](https://openairdocs.org/model/brian-turner-northern-explorer) (registry code 05634NZ) (OpenAirDocs) - Registry engine: [Lycoming O-320-A2B](https://openairdocs.org/engine/lycoming-o-320-a2b) (registry code 42101, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 072515 - Year built: 2015 - Airframe hours: 205 - Engines: Lycoming O-320-A2B 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: 100 hour, June 8, 2016 - Departed: 7AK4, WASILLA, AK - Destination: 7AK4, WASILLA, AK - Equipment: Satellite tracking device, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; injuries: none; private; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review November 11, 2014; seat: front; restraint: 3-point; flight hours: 600 total, 500 in this make and model, 600 as pilot in command, 150 in the last 90 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft overcast - Temperature: 61 °F, dew point 57 °F - Altimeter: 29.55 inHg - Observed at: PAAQ, 30 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 20160807023979A](https://openairdocs.org/incident/20160807023979A), Aug 7, 2016: 2015 Brian Turner NORTHERN EXPLORER, Chickaloon, AK, Substantial damage. Pilot stated while "buzzing" a potential landing strip, on the second go-around aircraft experienced caburator ice and he made a forced landing on a… ## Other investigations on N907BT (1) 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. - [NTSB ANC25LA106](https://openairdocs.org/ntsb/ANC25LA106), Aug 6, 2025: Brian Turner Northern Explorer (N907BT), Delta Junction, AK, substantial damage. Probable cause: The pilot’s failure to maintain obstacle clearance during landing, which resulted in an impact with trees. ## Docket (3 files) The files NTSB released with the investigation on December 14, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93808. 2.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 778 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40447577&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Photographs (item 2, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40447578&FileExtension=.PDF&FileName=Accident%20Photographs%20-Master.PDF - Pilot's Statement (item 3, .PDF, 102 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40447579&FileExtension=.PDF&FileName=Pilot%27s%20Statement-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.