# NTSB ERA14LA208: Alon A2, N6364V, Apex, NC, April 27, 2014 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: April 27, 2014, 17:00 local (21:00 UTC) - Place: Apex, NC - Coordinates: 35.73611, -78.922775 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.7361&lon=-78.9228&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report February 4, 2015 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: CMI, FAA/FSDO - NTSB case key (mKey): 89121 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA14LA208 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/89121/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=89121 - Page: https://openairdocs.org/ntsb/ERA14LA208 ## Probable cause A total loss of engine power during initial climb for reasons that could not be determined during postaccident examination and testing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=0540102), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=0540102), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Alon A2, 2 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=0540102), [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: [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 pilot stated that, before the accident flight, the airplane had about 15 gallons of automotive gasoline in the fuel tanks. The taxi and initial takeoff were "normal"; however, when the airplane was about 100 ft above the trees that bordered the airport, the engine experienced a sudden total loss of power. The pilot then reduced the throttle and reapplied full throttle. Although the engine momentarily restarted, it then immediately lost power. The airplane subsequently impacted trees and came to rest inverted. Local authorities reported a strong fuel smell at the accident location, but the exact amount of spilled fuel could not be determined. Examination of the airframe and a subsequent test run of the engine revealed no mechanical anomalies that would have precluded normal operation. Federal Aviation Administration guidance indicates that vapor lock is a problem that mostly affects gasoline-fueled internal combustion engines and can result in a transient or complete loss of power. The guidance further states that restarting the engine from this state may be difficult because fuel can be vaporized by engine heat. Given that the ambient air temperature, the fuel flow condition (takeoff), and the likely engine temperature were conducive to the occurrence of vapor lock, it is possible that the loss of engine power was due to vapor lock; however, insufficient evidence existed to determine whether vapor lock occurred during the accident flight. The weather conditions about the time of the accident were conducive to the accumulation of carburetor icing at cruise and glide power; however, given the pilot's statement that the engine operated "normally" until the sudden loss of power and that the airplane was climbing at a high power setting, it is not likely that the carburetor accumulated ice. ## Factual narrative A subsequent examination, of the engine at a storage facility, under NTSB oversight, revealed minimal external damage. The throttle, mixture, and carburetor heat controls remained attached to the engine and operated without anomalies. The engine remained attached to the airframe and was fitted with a 5 gallon fuel container, between the wing root and the carburetor, to facilitate an engine run. The wings were removed at the wing root to facilitate transport, and continuity was not confirmed from fuel tank to the separation point. The engine started and operated through various power settings with no abnormalities noted. No anomalies were noted from the 5 gallon fuel container through the fuel system. FAA Guidance According to an NTSB accident report (ERA12LA131), testing conducted at the FAA Technical Center revealed that vapor pressure of autogas can vary widely as formulations are changed seasonally, and according to local requirements. High vapor pressure can promote vapor lock in aircraft fuel systems causing engine power to be reduced or the engine to completely fail and testing by the FAA William J. Hughes Technical Center concluded that autogas with high vapor pressure can accelerate the formation of carburetor ice. The Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25A) defines vapor lock as "A problem that mostly affects gasoline-fuelled internal combustion engines. It occurs when liquid fuel changes state from liquid to gas while still in the fuel delivery system. This disrupts the operation of the fuel pump, causing loss of feed pressure to the carburetor or fuel injection system, resulting in transient loss of power or complete stalling. Restarting the engine from this state may be difficult. The fuel can vaporize due to being heated by the engine, by the local climate, or due to a lower boiling point at high altitude." DOT/FAA/CT-87/05 "Autogas in General Aviation Aircraft," states in part "The conditions which define the worst case for vapor lock testing (i.e., most likely to result in vapor lock) are as follows. 1. Takeoff fuel flow 2. Initial fuel temperature between 38 and 43 degrees Celsius (100 to 110 degrees Fahrenheit) 3. Ambient air temperature of 29 degrees Celsius or higher (85 degrees Fahrenheit). 4. Engine at operating temperatures typically found after a prolonged idling or a hot soak. 5. ASTM class E (winter grade) fuel if the testing is for autogas" An FAA chart, titled "Conditions Favoring Carb Ice Formation," indicated that with the ambient temperature and dew point, "Icing at glide and cruise power" was probable. The accident airplane, an Alon A2 (serial number A-40), was manufactured in 1965. It was registered with the FAA on a standard airworthiness certificate for normal operations. The airplane had a total time of 1,872.36 hours as of the last annual inspection, which was completed on January 4, 2014. The airplane was powered by a Continental C90 series engine. As of the last annual inspection, theengine had accumulated a total of 1,661 hours, with 287 hours since last major overhaul. On April 27, 2014, about 1700 eastern daylight time, an Alon A2, N6364V, experienced a total loss of engine power shortly after takeoff from Deck Airpark (NC11), Apex, North Carolina. The pilot subsequently made an off-airport forced landing into a forest. The private pilot sustained minor injuries, and the passenger was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the local flight. The airplane was registered to and operated by a private individual under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. The pilot reported that the taxi and initial takeoff were "normal;" however, when the airplane was about 100 feet above the trees that bordered the airport, the engine experienced a total loss of power. The pilot retarded the throttle and immediately reapplied full throttle. The engine subsequently restarted, but immediately lost power again. He then performed a forced landing into the trees, about 500 feet past the departure end of the runway. The pilot reported that he had about 15 gallons of autogas in the fuel tanks prior to departure. The 1651 recorded weather observation at Raleigh-Durham International Airport (RDU), Raleigh, North Carolina, located approximately 10 miles to the northeast of the accident location, included wind from 210 degrees at 6 knots, 10 miles visibility, scattered clouds 25,000 feet above ground level, temperature 28.3 degrees C, dew point 8.9 degrees C; altimeter setting 29.92 inches of mercury According to pilot provided information and Federal Aviation Administration (FAA) records, the pilot held a private pilot certificate with a rating for airplane single-engine land. He held a third-class medical certificate, which was issued on August 20, 2013. The pilot reported 1471.6 total flight hours, with 38.3 of those hours in the accident airplane make and model. Initial examination of the aircraft by an FAA inspector revealed that the airplane impacted several trees and came to rest inverted between two trees, resulting in substantial damage to the wings and fuselage. Local authorities reported to the inspector that there was a strong fuel smell at the accident scene; however, the fuel tank selected at takeoff was not noted or provided to the NTSB. ## Aircraft - Registration: [N6364V](https://openairdocs.org/aircraft/N6364V), registered now, S/N A-40, 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-40 - Year built: 1965 - Airframe hours: 1878.89 - Engines: Continental C90-16F 90 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 4, 2014, 7 hours before - Departed: NC11, Apex, NC - Destination: 2GC, Grays Creek, NC - Airport: NC11, Deck Airpark, runway 22, 1,950 × 100 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 74; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review August 6, 2013; seat: left; flight hours: 1,525.5 total, 38.2 in this make and model, 1,471.5 as pilot in command, 3.2 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 48 °F - Altimeter: 29.92 inHg - Observed at: KRDU, 11 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 20140427005219A](https://openairdocs.org/incident/20140427005219A), Apr 27, 2014: Alon A2, Apex, NC, Substantial damage. Pilot reported that shortly after takeoff the engine stopped running, had no place to land and crashed into the trees. ## Docket (11 files) The files NTSB released with the investigation on December 31, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=89121. 12.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420506&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Memorandum of Record – FAA Description of Accident Scene (item 2, .PDF, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420507&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20%E2%80%93%20FAA%20Description%20of%20Accident%20Scene-Master.PDF - Memorandum for Record – Engine Exam (item 3, .PDF, 116 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420508&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20%E2%80%93%20Engine%20Exam-Master.PDF - Recent Annual Inspection [Excerpts] (item 4, .PDF, 370 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420510&FileExtension=.PDF&FileName=Recent%20Annual%20Inspection%20%5BExcerpts%5D-Redacted.PDF - Memorandum of Record RDU Weather (item 5, .PDF, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420511&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20RDU%20Weather-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 6, .PDF, 335 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420512&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 7, .PDF, 148 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420513&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.PDF - FAA Carburetor Icing Chart (item 8, .PDF, 265 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420516&FileExtension=.PDF&FileName=FAA%20Carburetor%20Icing%20Chart-Master.PDF - Photo 1 – Airplane at Rest (Photo Courtesy of FAA) (item 9, .PDF, 220 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420517&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20Airplane%20at%20Rest%20(Photo%20Courtesy%20of%20FAA)%0D%0A-Master.PDF - Photo 2 –Left Side of Airplane at Rest (Courtesy of FAA) (item 10, .PDF, 5.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420518&FileExtension=.PDF&FileName=Photo%202%20%E2%80%93Left%20Side%20of%20Airplane%20at%20Rest%20(Courtesy%20of%20FAA)%0D%0A-Master.PDF - Photo 3 – Right Side of Airplane at Rest (Courtesy of FAA) (item 11, .PDF, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420519&FileExtension=.PDF&FileName=Photo%203%20%E2%80%93%20Right%20Side%20of%20Airplane%20at%20Rest%20(Courtesy%20of%20FAA)%0D%0A-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.