# NTSB ERA14LA089: FK Lightplanes FK9 ELA SW, N611SP, Canton, GA, January 4, 2014

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 4, 2014, 15:30 local (20:30 UTC)
- Place: Canton, GA
- Coordinates: 34.230834, -84.29528 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.2308&lon=-84.2953&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report April 27, 2015
- Report: Approved by Office Director
- NTSB office: Eastern Region Aviation
- Parties: FAA/FSDO, Rotax - Technical Advisor to Austria, Austrian Civil Aviation Safety Investigation, Commission of Aircraft Accident Investigation
- SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs)
- NTSB case key (mKey): 88646
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA14LA089
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88646/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88646
- Page: https://openairdocs.org/ntsb/ERA14LA089

## Probable cause

A partial loss of engine power during cruise flight due to an overly lean fuel-air mixture, which resulted from an incorrectly installed float chamber vent line and led to a subsequent off-airport landing.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [FK Lightplanes FK9 ELA SW, 1 case](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=060008D), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md)
- [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [FK Lightplanes FK9 ELA SW, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=060008D), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md)
- [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [FK Lightplanes FK9 ELA SW, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=060008D), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [FK Lightplanes FK9 ELA SW, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=060008D), [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: [FK Lightplanes FK9 ELA SW, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=060008D), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [FK Lightplanes FK9 ELA SW, 1 case](https://openairdocs.org/ntsb-events/094/sequence.md?model=060008D), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md)

## Analysis

The pilot reported that, while in cruise flight, the engine experienced a partial power loss. The airplane was unable to maintain altitude, so the pilot chose to perform an off-airport landing to an open field. During the landing roll, the airplane encountered a berm, became airborne, and then landed hard. Examination of the engine revealed that the carburetor float chamber vent lines had been incorrectly routed to the air filter. The engine manufacturer's installation manual cautioned that the float chamber vent lines must not be routed into the slipstream or down the firewall because "pressure differences between the intake pressure in the carburetor chambers may lead to engine malfunction due to incorrect fuel supply." Therefore, it is likely that the incorrectly installed vent line resulted in back pressure to the float bowl that exceeded the normal operating range, which would have affected the engine's fuel-air mixture and led to the partial loss of engine power.

## Factual narrative

Rotax Installation Manual A review of the Rotax installation manual for the 912 Series engine, Chapter 15.1 "Requirements on the carburetor" provided a caution message which stated in part, "The float chamber venting lines have to be routed into a ram-air and vacuum free zone or into the airbox…these lines must not be routed into the slipstream or down the firewall. Pressure differences between intake pressure in the carburetor chambers may lead to engine malfunction due to incorrect fuel supply." According to a representative from the engine manufacturer, the routing of the carburetor venting line to the air filters influenced the fuel-air mixture of the engine and, in certain flight conditions, the engine may experience a lack of fuel due in part to the back pressure in the float bowl exceeding the normal operating range. FAA Special Airworthiness Information Bulletin A review of FAA Special Airworthiness Information Bulletin, CE-09-35, dated June 30, 2009, revealed that the temperature and dew point at CNI was not conducive to carburetor icing. The two-seat, high-wing, fixed-gear airplane was built in 2010. It was powered by a Rotax 912ULS 100-hp engine and was driven by a Warpdrive DUC 3-blade fixed-pitch propeller. The most recent condition inspection was completed on March 5, 2013 with a recorded aircraft time in service of 503.0 hours. According to the pilot, at the time of the accident, the aircraft had accumulated 590.9 total hours. On January 4, 2014, about 1530 eastern standard time, a FK Lightplanes FK9, light-sport airplane, N611SP, was substantially damaged following a partial loss of engine power while in cruise flight near Canton, Georgia. The pilot subsequently made an off airport forced landing to an open field. The certificated private pilot and passenger were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the flight destined for Cobb County Airport – McCollum Field (RYY), Kennesaw, Georgia. The fight originated from Mustang Field Airport (0GA1), Hartwell, Georgia, about 1500. 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. According to the pilot, while in cruise flight the fuel pressure gauge indicated a decrease in fuel pressure from 5.4 gallons per hour (gph) to 0.1 gph and the rpm subsequently decreased. After activating the auxiliary fuel pump, he was able to restart the engine; however, only partial power was restored. Unable to maintain altitude, an off airport emergency landing was performed to a nearby field. Upon landing the airplane encountered a berm, became airborne, and landed hard, which resulted in the left main landing gear and nose landing gear to separating from the airplane. The recorded weather at Cherokee County Airport (CNI), Canton, Georgia, which was located 8 miles to the northwest of the accident location, included overcast clouds at 1500 feet aboveground level, wind from 090 degrees at 9 knots, temperature 2 degrees C, and dew point -11 degrees C. The pilot, age 30, held a private and sport pilot certificate for airplane single-engine land, and a third-class medical certificated issued December 10, 2012. The pilot reported 83.7 total flight hours with 16.8 of those hours in the accident aircraft make and model. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that it came to rest with the left wing contacting the ground and the firewall was damaged. The left wing fuel tank had an undetermined amount of fuel and the right wing fuel tank was devoid of fuel. Initial examination of the engine revealed compression on all cylinders and the automotive fuel, that was located throughout the fuel system, was free of debris. Examination of the engine by a representative from the engine manufacturer, with FAA oversight, revealed that the engine remained attached to the airframe and that the spark plugs appeared "normal" in appearance. The electric fuel pump was tested and was operational, fuel was present in the fuel bowls, and the airframe fuel vent tube was observed with no blockage noted. The engine was started and operated at normal power settings utilizing the fuel from the aircraft, with no abnormalities noted. Further examination revealed that the float chamber vent lines had been routed from the carburetor into the air filter. The engine did not have, nor was it required to have, carburetor heat and utilized radiant heating from the engine to minimize carburetor icing possibilities.

## Aircraft

- Registration: [N611SP](https://openairdocs.org/aircraft/N611SP), registered now, S/N 09-419, built 2010 (OpenAirDocs)
- Reported make and model: FK LIGHTPLANES FK9 ELA SW
- Registry model: [FK Lightplanes FK9 ELA SW](https://openairdocs.org/model/fk-lightplanes-fk9-ela-sw) (registry code 060008D) (OpenAirDocs)
- Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 09-419
- Year built: 2010
- Airframe hours: 591
- Engines: Rotax 912ULS 100 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Special light-sport (Special)
- Last inspection: Condition, March 5, 2013, 61 hours before
- Departed: 0GA1, Hartwell, GA
- Destination: RYY, Atlanta, GA
- Airport: CNI, Cherokee County

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; seat: left; restraint: 3-point; flight hours: 83.6 total, 16.7 in this make and model, 45.5 as pilot in command, 7.5 in the last 90 days, 4.5 in the last 30 days, 2.5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 9 knots
- Visibility: 10 statute miles
- Lowest ceiling: 1,500 ft overcast
- Temperature: 36 °F, dew point 12 °F
- Altimeter: 30.27 inHg
- Observed at: KCNI, 8 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 20140104001119A](https://openairdocs.org/incident/20140104001119A), Jan 4, 2014: Fk Lightplanes FK9 ELA SW, Canton, GA, Substantial damage. Inspector kearby received call from the rocc on 01 January 2014 stating a lightplanes FK9 ela sw had gone down in a field near Canton, GA. At the time of the…

## Docket (14 files)

The files NTSB released with the investigation on March 31, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88646. 9.3 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 402 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40408139&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Written Statements (item 2, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407482&FileExtension=.PDF&FileName=Written%20Statements-Redacted.PDF
- Operator's Emailed Statement to FAA (item 3, .PDF, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424283&FileExtension=.PDF&FileName=Operator%27s%20Emailed%20Statement%20to%20FAA-Redacted.PDF
- Non-Volatile Memory Devices – Specialist Factual Report (item 4, .PDF, 2 photos, 198 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424284&FileExtension=.PDF&FileName=Non-Volatile%20Memory%20Devices%20%E2%80%93%20Specialist%20Factual%20Report-Master.PDF
- Non Volatile Memory Devices – Tabular Data Addendum 1 EMS D100 (item 5, .CSV, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424285&FileExtension=.csv&FileName=Non%20Volatile%20Memory%20Devices%20%E2%80%93%20Tabular%20Data%20Addendum%201%20EMS%20D100-Master.csv
- Non Volatile Memory Devices – Tabular Data Addendum 2 EFIS D120 (item 6, .CSV, 4.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424286&FileExtension=.csv&FileName=Non%20Volatile%20Memory%20Devices%20%E2%80%93%20Tabular%20Data%20Addendum%202%20EFIS%20D120-Master.csv
- Maintenance Records Most Recent Annual Inspection [Excerpts] (item 7, .PDF, 100 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424287&FileExtension=.PDF&FileName=Maintenance%20Records%20Most%20Recent%20Annual%20Inspection%20%5BExcerpts%5D-Redacted.PDF
- Memorandum for Record – Conversation with a Representative/Tech Advisor from the Engine Manufacturer (item 8, .PDF, 113 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424288&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20%E2%80%93%20Conversation%20with%20a%20Representative%2FTech%20Advisor%20from%20the%20Engine%20Manufacturer-Master.PDF
- Memorandum of Record – Canton, Georgia Weather (item 9, .PDF, 138 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424290&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20%E2%80%93%20Canton,%20Georgia%20Weather-Master.PDF
- Installation Manual for the Rotax 912 Series engine [Excerpts] (item 10, .PDF, 107 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424289&FileExtension=.PDF&FileName=Installation%20Manual%20for%20the%20Rotax%20912%20Series%20engine%20%5BExcerpts%5D-Master.PDF
- FAA Carb Ice Chart from SAIB (item 11, .PDF, 265 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424291&FileExtension=.PDF&FileName=FAA%20Carb%20Ice%20Chart%20from%20SAIB-Master.PDF
- Photo 1 – Right Side of Airplane at Rest (Courtesy of the FAA) (item 12, .PDF, 100 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424295&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20Right%20Side%20of%20Airplane%20at%20Rest%20(Courtesy%20of%20the%20FAA)-Master.PDF
- Photo 2 – Left Side of Airplane at Rest (Courtesy of the FAA) (item 13, .PDF, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424296&FileExtension=.PDF&FileName=Photo%202%20%E2%80%93%20Left%20Side%20of%20Airplane%20at%20Rest%20(Courtesy%20of%20the%20FAA)-Master.PDF
- Photo 3 – Vent Line Routing as Found (Courtesy of Rotax) (item 14, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424297&FileExtension=.PDF&FileName=Photo%203%20%E2%80%93%20Vent%20Line%20Routing%20as%20Found%20(Courtesy%20of%20Rotax)-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.

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