# NTSB CEN15LA407: Alon A2, N6359V, Laramie, WY, September 11, 2015 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: September 11, 2015, 07:40 local (13:40 UTC) - Place: Laramie, WY - Coordinates: 41.26472, -105.474998 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.2647&lon=-105.4750&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-climb to cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report February 17, 2016 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Continental Motors, Inc., FAA Denver FSDO - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 91967 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN15LA407 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91967/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91967 - Page: https://openairdocs.org/ntsb/CEN15LA407 ## Probable cause The pilot’s failure to use carburetor heat in cruise flight while operating in an area conducive to serious carburetor icing, which resulted in a loss of engine power and an off-airport landing. Contributing to the accident was the pilot's decision to continue flight toward rising mountainous terrain when the airplane could not maintain altitude. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=0540102), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=0540102), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [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: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/01023020/cases.md?model=0540102), [All aircraft, 108 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md) - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=0540102), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=0540102), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Decision related to condition (probable cause); cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=0540102), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Alon A2, 2 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=0540102), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-climb to cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=0540102), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Alon A2, 3 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=0540102), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Alon A2, 7 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0540102), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot reported that, after departing and then making a slow circling climb to about 9,500 ft mean sea level (msl), the airplane was unable to climb any higher and was occasionally descending. The pilot began to fly on course toward higher terrain, and the engine suddenly began to lose power. The pilot applied carburetor heat, but engine power was not restored. The airspeed then slowed, and the airplane descended. The airplane impacted the concrete median barrier on the highway in a narrow mountain pass at an estimated terrain elevation of 7,980 ft msl and then came to rest upright. There was a fuel spill at the scene but no postimpact fire, and the injured pilot was able to exit the airplane without assistance. A postaccident examination of the airplane and engine found no preaccident mechanical malfunctions or failures that would have precluded normal operation. The pilot reported that the airplane had been recently fitted with a 4-point inertial reel shoulder harness system and that it is likely that his use of that shoulder harness system prevented him from sustaining a more serious injury. The weather conditions about the time of the accident were conducive to the accumulation of serious carburetor icing at all power settings. Federal Aviation Administration guidance states that, when conditions are conductive to carburetor icing, the pilot should immediately apply carburetor heat and that the heat should be left on until the pilot is certain that all of the ice has been removed. It is likely that the engine began to lose power due to carburetor ice and that the timely application of carburetor heat would have restored engine power. ## Factual narrative On September 11, 2015, about 0740 mountain daylight time, an Alon A2 Aircoupe, single-engine airplane, N6359V, impacted terrain during climb to cruise near Laramie, Wyoming. The pilot was seriously injured. The airplane sustained substantial damage to both wings and the fuselage. The airplane was registered to and operated by a private individual, as a 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions (VMC) prevailed at the accident site and a flight plan had not been filed. The airplane departed Laramie Regional Airport (LAR), Laramie, Wyoming, about 0720 and was destined for North Platte Regional Airport (LBF), North Platte, Nebraska.The pilot reported that after departing LAR he had circled near the airport to slowly climb to about 9,500 feet above mean sea level (msl). On reaching 9,500 ft. the airplane would not climb any higher and was occasionally descending. The pilot began to fly on course toward higher terrain when the engine suddenly began to lose power. The pilot applied carburetor heat, which had no effect. The airspeed slowed and the airplane descended. The pilot attempted to force land the airplane on a highway and reported that he lost sight of the highway just before impact. The airplane, traveling eastbound, impacted the concrete median barrier on the interstate highway in a narrow mountain pass at an estimated terrain elevation of 7,980 feet msl and came to rest upright on the shoulder of the westbound lane of traffic. Witnesses saw the crash and immediately called 9-1-1. There was a fuel spill at the scene, but no postimpact fire, and the injured pilot was able to exit the airplane without assistance. The pilot noted that the airplane had been recently fitted with a 4-point inertial reel shoulder harness system and he was certain that that shoulder harness system saved him from a much more serious injury. A postaccident examination of the airplane and engine found no preimpact anomalies which would have prevented normal operation. The nearest aviation weather reporting station was located at LAR, about 10 miles west from the accident site. At 0753, the LAR automated surface observing system reported the following weather conditions: wind 180 degrees at 7 knots, visibility 10 miles, clear of clouds, temperature 8 degrees Celsius (C), dew point 6 degrees C, and an altimeter setting of 30.39 inches of Mercury. Data from the National Oceanic and Atmospheric Administration showed that, at the accident location, at 0750, the altitude of the sun was about 13 degrees above the horizon and the azimuth of the sun was about 095 degrees. Apparent sunrise occurred at 0638. The carburetor icing probability chart from Federal Aviation Administration (FAA) Special Airworthiness Information Bulletin (SAIB): CE-09-35 Carburetor Icing Prevention, June 30, 2009, shows a probability of serious icing at all power settings at the temperature and dew point reported at the time of the accident. ADDITIONALINFORMATION: The FAA Pilot's Handbook of Aeronautical Knowledge states that when conditions are conductive to carburetor icing that carburetor heat should be applied immediately and should be left on until the pilot is certain all the ice has been removed. Additionally, if ice is present the application of partial carburetor heat or leaving heat on for an insufficient time might aggravate the situation. ## Aircraft - Registration: [N6359V](https://openairdocs.org/deregistered/N6359V-2019-01-29), registration cancelled 2019-01-29, S/N A-35, built 1965 (OpenAirDocs) - Reported make and model: ALON A2 - Registry model: [Alon A2](https://openairdocs.org/model/alon-a2) (registry code 0540102) (OpenAirDocs) - Registry engine: [Continental C90 series](https://openairdocs.org/engine/continental-c90-series) (registry code 17009, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: A-35 - Year built: 1965 - Airframe hours: 2875 - Engines: CONTINENTAL C90-16F 90 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 20, 2015, 13 hours before - Departed: LAR, LARAMIE, WY - Destination: LBF, NORTH PLATTE, NE - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: serious; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review June 20, 2014; seat: left; restraint: 4-point; flight hours: 213 total, 67 in this make and model, 149 as pilot in command, 21 in the last 90 days, 18 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 46 °F, dew point 43 °F - Altimeter: 30.38 inHg - Turbulence: Light - Observed at: KLAR, 10 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 20150911016089A](https://openairdocs.org/incident/20150911016089A), Sep 11, 2015: Alon A2, Laramie, WY, Substantial damage. PIC operated aircoupe A-2 registration N6359V from klar enroute to klbf PIC reported aircraft loss of power followed by an unrecoverable descent into… ## Other investigations on N6359V (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 CHI67D0021](https://openairdocs.org/ntsb/CHI67D0021), May 28, 1966: Alon A-2 (N6359V), Menomonee Fls, WI, substantial damage ## Docket (7 files) The files NTSB released with the investigation on January 12, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91967. 3.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (Best Copy) (item 1, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435508&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20(Best%20Copy)-Master.PDF - Summary of Findings (item 2, .PDF, 78 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435509&FileExtension=.PDF&FileName=Summary%20of%20Findings-Master.PDF - Maps (item 3, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435510&FileExtension=.PDF&FileName=Maps-Master.PDF - Weather Summary (item 4, .PDF, 539 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435511&FileExtension=.PDF&FileName=Weather%20Summary-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 5, .PDF, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435512&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 6, .PDF, 86 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435513&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Master.PDF - Photos (item 7, .PDF, 4 photos, 250 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435514&FileExtension=.PDF&FileName=Photos-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.