# NTSB CEN13LA398: Flight Design Ctls, N549LS, Sandwich, IL, July 7, 2013

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: July 7, 2013, 10:50 local (15:50 UTC)
- Place: Sandwich, IL
- Coordinates: 41.638332, -88.644447 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.6383&lon=-88.6444&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report December 2, 2013
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: Federal Aviation Administration, DuPage FSDO
- SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs)
- NTSB case key (mKey): 87414
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN13LA398
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87414/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87414
- Page: https://openairdocs.org/ntsb/CEN13LA398

## Probable cause

The pilot’s failure to recognize the formation of carburetor ice during cruise descent and apply carburetor heat, which resulted in the total loss of engine power.

## 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 · Awareness of condition (probable cause); cases with it: [Flight Design CTLS, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=060005B), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/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: [Flight Design CTLS, 3 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=060005B), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md)

## Sequence of events

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

- [Enroute-descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Flight Design CTLS, 6 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=060005B), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Flight Design CTLS, 6 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=060005B), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Flight Design CTLS, 8 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=060005B), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md)

## Analysis

The pilot reported that as the airplane was descending through about 4,700 feet mean sea level, the engine began to run rough and eventually lost complete power. He noted that the engine monitoring system indicated that there was no fuel flow, despite the airplane having about 16 gallons of automobile fuel still available. The pilot reported that his several attempts to restart the engine were unsuccessful. He requested radar vectors from air traffic control to the nearest airport; however, he was unable to reach the airfield, so the pilot made a forced landing to a cornfield. A postaccident examination did not reveal any mechanical or fuel system anomalies that would have precluded normal engine operation, and the engine subsequently started and ran without any anomalies. Additional examination of the fuel system revealed that an ample amount of uncontaminated automobile fuel was available. The weather conditions at the time of the accident were conducive to the accumulation of carburetor ice during engine operations at descent engine power settings. Additionally, the pilot’s use of automobile fuel increased the likelihood of carburetor ice accumulation because it is more volatile and therefore absorbs more heat from the mixing air when vaporizing for engine consumption. The pilot stated that he did not apply carburetor heat after the loss of engine power. It is likely that the pilot’s use of automobile fuel and his flight in weather conditions that were conducive for carburetor icing resulted in the formation of carburetor ice during the airplane’s descent.

## Factual narrative

On July 7, 2013, at 1050 central daylight time, a Flight Design GmbH model CTLS light-sport airplane, N549LS, was substantially damaged during a forced landing near Sandwich, Illinois. The commercial pilot and his passenger sustained minor injuries. The airplane was registered to and operated by a private individual, under the provisions of 14 Code of Federal Regulations Part 91, while on a visual flight rules flight plan. Day visual meteorological conditions prevailed for the pleasure flight that departed Creve Coeur Airport (1H0), St. Louis, Missouri, about 0912, and was en route to Waukegan Regional Airport (KUGN), Waukegan, Illinois. The pilot reported that as the flight descended through 4,700 feet mean sea level the engine began to run rough and eventually lost complete power. He noted that the engine monitoring system indicated that there was no fuel flow, despite the airplane having 16 gallons of automobile fuel still available between the two wing tanks. The pilot reported that his several attempts to restart the engine were unsuccessful in restoring engine power. He requested radar vectors from air traffic control to the nearest airport; however, the airplane was unable to reach an airfield and a forced landing was made into a cornfield. The nose and main landing gear collapsed during the forced landing, which resulted in substantial damage to the forward fuselage. Two Federal Aviation Administration (FAA) airworthiness inspectors examined the airplane which had been recovered from the cornfield. The postaccident examination revealed that airplane had ample amount of automobile fuel to sustain engine operation. The carburetor heat control was found in the OFF position. The engine started and ran without any anomalies for a period of about 2 minutes. The engine responded to throttle inputs during the operational test run with the electric fuel pump in the OFF position. Additional examination of the fuel system filter, gascolator bowl, and the two carburetor bowls revealed no particulate or water contamination. The postaccident examination did not reveal any mechanical or fuel system anomalies that would have prevented normal engine operation. The nearest aviation weather reporting station was located at Aurora Municipal Airport (KARR), Sugar Grove, Illinois, about 13 miles northeast of the accident site. At 1052, the KARR automated surface observing system reported the following weather conditions: wind 210 degrees true at 10 knots, visibility 10 miles, sky clear, temperature 27 degrees Celsius, dew point 19 degrees Celsius, altimeter setting 30.02 inches of mercury. A postaccident upper atmosphere model indicated that the temperature and dew point at 5,000 feet msl was 17.2 degrees Celsius and 9.9 degrees Celsius, respectively. The carburetor icing probability chart included in FAA Special Airworthiness Information Bulletin No. CE-09-35, Carburetor Icing Prevention, indicates that there was a serious risk of accumulating carburetor iceat descent engine power settings. 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. A Transport Canada report entitled The Use of Automobile Gasoline in Aviation, No. TP 10737, indicates that the likelihood of experiencing carburetor icing is higher when operating on automobile fuel. The report notes that automobile fuel has a higher volatility than aviation fuels and, as such, absorbs more heat from the mixing air while being atomized for engine consumption. The result is the potential for carburetor ice to be accumulated at higher ambient temperatures when compared to aviation fuels. When asked if he had applied carburetor heat following the loss of engine power, the pilot replied that he had never used carburetor heat in the six years that he had flown the accident airplane. Additionally, he indicated that a vast majority of his flying experience was in fuel-injected airplanes, and as such, his memorized emergency procedures did not include the application of carburetor heat following a loss of engine power.

## Aircraft

- Registration: [N549LS](https://openairdocs.org/deregistered/N549LS-2014-07-09), registration cancelled 2014-07-09, S/N 07-11-19, built 2007 (OpenAirDocs)
- Reported make and model: Flight Design GmbH CTLS
- Registry model: [Flight Design CTLS](https://openairdocs.org/model/flight-design-ctls) (registry code 060005B) (OpenAirDocs)
- Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 07-11-19
- Airframe hours: 553
- Engines: Rotax 912 ULS 100 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Daniel E. Mayworm
- Registered owner: Daniel E. Mayworm
- Airworthiness certificate: Special, Special light-sport (Special)
- Last inspection: Annual, January 9, 2013
- Departed: 1H0, St. Louis, MO
- Destination: UGN, Waukegan, IL
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 86; injuries: minor; commercial; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: sport pilot; last flight review May 24, 2013; seat: left; flight hours: 7,290 total, 440 in this make and model, 7,290 as pilot in command, 81 in the last 90 days, 9 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 210° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 66 °F
- Altimeter: 30.02 inHg
- Observed at: KARR, 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 20130707011469A](https://openairdocs.org/incident/20130707011469A), Jul 7, 2013: Flight Design Gmbh CTLS, Sandwich, IL, Substantial damage. The aircraft departed creve coeur airport(1H0), near st. louis, MO on a pleasure Flight enroute to waukegan, IL (ugn). Pilot contacted ATC and reported fuel…

## Docket (7 files)

The files NTSB released with the investigation on August 5, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87414. 2.7 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 872 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396599&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Memorandum of Conversation (Pilot Dennis Mayworm) -- 1st Interview (item 2, .PDF, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396600&FileExtension=.PDF&FileName=Memorandum%20of%20Conversation%20(Pilot%20Dennis%20Mayworm)%20--%201st%20Interview-Master.PDF
- Memorandum of Conversation (Pilot Dennis Mayworm) -- 2nd Interview (item 3, .PDF, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396897&FileExtension=.PDF&FileName=Memorandum%20of%20Conversation%20(Pilot%20Dennis%20Mayworm)%20--%202nd%20Interview-Master.PDF
- Memorandum of Conversation (FAA Inspector Victor Liberatore) (item 4, .PDF, 61 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396601&FileExtension=.PDF&FileName=Memorandum%20of%20Conversation%20(FAA%20Inspector%20Victor%20Liberatore)-Master.PDF
- FAA Speical Airworthiness Alert Bulletin No. CE-09-35 -- Carburetor Icing Prevention (item 5, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396602&FileExtension=.PDF&FileName=FAA%20Speical%20Airworthiness%20Alert%20Bulletin%20No.%20CE-09-35%20--%20Carburetor%20Icing%20Prevention-Master.PDF
- Transport Canada Report No. TP 10737 -- The Use Of Automobile Gasoline In Aviation (item 6, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396603&FileExtension=.PDF&FileName=Transport%20Canada%20Report%20No.%20TP%2010737%20--%20The%20Use%20Of%20Automobile%20Gasoline%20In%20Aviation-Master.PDF
- Weather Information (item 7, .PDF, 102 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396604&FileExtension=.PDF&FileName=Weather%20Information-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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