# NTSB WPR11FA120: Aeronca O-58C, N47503, San Luis Obispo, CA, February 3, 2011 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: February 3, 2011, 09:45 local (17:45 UTC) - Place: San Luis Obispo, CA - Coordinates: 35.312778, -120.675003 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.3128&lon=-120.6750&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: Fatal - Injuries: 1 fatal, 1 minor - Status: Completed, report May 3, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO, Teledyne Continental Motors - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 78275 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11FA120 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78275/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78275 - Page: https://openairdocs.org/ntsb/WPR11FA120 ## Probable cause The pilot’s delay in using carburetor heat, which resulted in a loss of engine power due to an encounter with carburetor icing conditions. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Contributed to outcome (probable cause); cases with it: [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/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: [All aircraft, 108 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/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: [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The airplane was in cruise flight at 3,500 feet mean sea level when the engine lost power. The pilot restarted the engine, and it ran for about 20 seconds before again losing power. He applied carburetor heat, but the cycle of losing power and restarting for a few seconds occurred several times. The pilot attempted to land in a field, but collided with trees at the edge of the field. There was no evidence of preimpact mechanical malfunction found during a postaccident examination of the airframe and engine. The meteorological conditions at the time of the accident were conductive to serious carburetor icing at cruise power. Although the pilot applied carburetor heat after the initial power loss, the engine likely did not run long enough to melt the ice and restore power. ## Factual narrative HISTORY OF FLIGHT On February 3, 2011, about 0945 Pacific standard time, an Aeronca 0-58C, N47503, collided with trees near San Luis Obispo, California. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot sustained minor injuries, and one passenger sustained fatal injuries; the airplane sustained substantial damage to the fuselage and wings. The cross-country personal flight departed Paso Robles, California, about 0920, with a planned destination of Oceano, California. Visual meteorological conditions prevailed, and no flight plan had been filed. A Federal Aviation Administration (FAA) inspector interviewed the pilot, and provided the following information. The pilot stated that the airplane was in cruise flight at 3,500 feet mean sea level (msl). The engine started to cough and lose power. He attempted to restart the engine, and it ran for about 20 seconds. He then applied carburetor heat, but the cycle of losing power and restarting for a few seconds occurred several times. The pilot attempted to land in a field, but collided with trees at the edge of the field. PERSONNEL INFORMATION The pilot reported that he held a private pilot certificate with a rating for airplane single-engine land. He was issued a third-class medical certificate on July 19, 2010, with the limitation that he must wear corrective lenses. The pilot reported that he had a total flight time of 315 hours. He logged 4.1 hours in the last 90 days, and 0.5 in the last 30 days. He stated that he had 20 hours in this make and model, and completed a biennial flight review on September 3, 2010. AIRCRAFT INFORMATION The airplane was an Aeronca O-58C (L-3B), serial number 43-8212. The owner reported that the airplane had a total airframe time of 910 hours. It had an annual inspection on April 30, 2010. The engine was a Continental Motors A-65-8, serial number 5292968. METEOROLOGICAL INFORMATION The closest official weather observation station was San Luis Obispo, California (KSBP), which was 4 nautical miles (nm) southeast of the accident site. The elevation of the weather observation station was 212 feet msl. An aviation routine weather report (METAR) for KSBP was issued at 0956 PST. It stated: wind calm; visibility 10 miles; sky clear; temperature 9/48 degrees Celsius/Fahrenheit; dew point 4/39 degrees Celsius/Fahrenheit; altimeter 30.48 inches of mercury; relative humidity 71 percent. TESTS AND RESEARCH Examination of the airframe and engine was conducted on February 8, 2011, at the facilities of Aircraft Recovery Services, Pearblossom, California. No evidence of preimpact mechanical malfunction was noted during the examination of the airframe and engine. Detailed examination notes are in the public docket. ADDITIONAL INFORMATION The FAA Aircraft Certification Service published Special Airworthiness Information Bulletin (SAIB) CE-09-35 on June 30, 2009, to inform pilots of the potential hazardsassociated with carburetor icing. The SAIB noted 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. It states that 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 (the venturi effect) causes sudden cooling, a significant amount of ice can build up within a fraction of a second. The SAIB contains a graph that illustrates the probability of carburetor icing for various temperature and relative humidity conditions. The conditions for this accident fell within the range of serious icing at cruise power. The FAA’s Handbook of Aeronautical Knowledge states that application of carburetor heat will cause a further reduction in power, and possibly engine roughness as melted ice goes through the engine. It states that these symptoms can last from 30 seconds to several minutes, depending on the severity of the icing. ## Aircraft - Registration: N47503 (not matched to a registry record) - Reported make and model: AERONCA O-58C - Category: Airplane - Serial number: 43-8212 - Airframe hours: 910 - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Jeffrey B Wells - Registered owner: Jeffrey B Wells - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 30, 2010 - Departed: Paso Robles, CA - Destination: Oceano, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: minor; private, sport pilot; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review September 3, 2010; seat: front; flight hours: 313 total, 20 in this make and model, 205 as pilot in command, 4 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 39 °F - Altimeter: 30.47 inHg - Observed at: KSBP, 4 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 20110203002239A](https://openairdocs.org/incident/20110203002239A), Feb 3, 2011: Aeronca 0-58B, San Luis Obispo, CA, Destroyed, 1 fatal. Pilot stated, while in cruise level flight, engine began operating rough, so he applied carb heat, but engine subsequently shut down. Pilot stated he… ## Docket (7 files) The files NTSB released with the investigation on March 29, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78275. 3.3 MB in all. - Global Positioning Device - Specialist's Factual Report (item 1, .PDF, 634 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40352099&FileExtension=.PDF&FileName=Global%20Positioning%20Device%20-%20Specialist%27s%20Factual%20Report-Master.PDF - Global Positioning Device - Attachment 1 (item 2, .CSV, 1 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40352100&FileExtension=.csv&FileName=Global%20Positioning%20Device%20-%20Attachment%201-Master.csv - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 3, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361781&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation FAA (item 4, .PDF, 35 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363375&FileExtension=.PDF&FileName=Record%20of%20Conversation%20FAA-Master.PDF - NTSB Airframe and Engine Exam Notes (item 5, .PDF, 291 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363376&FileExtension=.PDF&FileName=NTSB%20Airframe%20and%20Engine%20Exam%20Notes-Master.PDF - Chane of Custody GPS (item 6, .PDF, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363663&FileExtension=.PDF&FileName=Chane%20of%20Custody%20GPS-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 7, .PDF, 469 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363377&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-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.