# NTSB CEN19LA015: Cessna 172, N3973L, Houston, TX, October 27, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 27, 2018, 09:15 local (14:15 UTC) - Place: Houston, TX - Coordinates: 29.82361, -95.675552 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.8236&lon=-95.6756&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report April 20, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Continental Motors, Federal Aviation Administration - NTSB case key (mKey): 98552 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA015 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98552/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98552 - Page: https://openairdocs.org/ntsb/CEN19LA015 ## Probable cause The pilot's failure to apply carburetor heat while operating in an area conducive to carburetor icing, which resulted in a total loss of engine power on approach and subsequent forced landing into a creek. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [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: [All aircraft, 108 cases](https://openairdocs.org/ntsb-findings/01023020/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: [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Enroute: 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) - [Enroute: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/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: 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 commercial pilot reported that, as the airplane approached the runway after a short local, personal flight, the engine lost power. The pilot checked the fuel valve, mixture, and engaged the starter, but engine power was not restored. The pilot stated that the airplane was "headed directly toward a concrete revetment on the south bank" of a creek, so he banked the airplane left, and it subsequently impacted in the creek. During recovery of the airplane, the fuel selector was found in the "both" position, and the throttle, mixture, and carburetor heat controls were found in the "forward" (off) position. Examination of the wreckage revealed no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation. The atmospheric conditions at the time that the engine lost power were conducive to serious icing at any power, moderate icing at cruise power, and serious icing at descent power. Given the evidence, it is likely that carburetor ice accumulated during the flight and that the pilot did apply carburetor heat, which resulted in a loss of all engine power. ## Factual narrative On October 27, 2018, about 0915 central daylight time, a Cessna 172 G airplane, N3973L, impacted a creek near Houston, Texas, during a forced landing following a loss of engine power. The commercial pilot and two passengers were uninjured. The airplane sustained substantial wing damage during the forced landing. The airplane was registered to IFR Flyers LLC and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions prevailed in the area about the time of the accident, and the flight was not operated on a flight plan. The local flight originated from the West Houston Airport (IWS), near Houston, Texas.According to the pilot's accident report, the purpose of the flight was an orientation flight for two Young Eagles passengers. After departing from runway 15, the pilot followed interstate highway 10 to highway 99, and then flew north about 5 miles. He then flew east and entered a final for runway 15. On short final the pilot added power, but the engine did not respond. He checked the fuel valve, mixture, and engaged the starter with no engine response. He stated, "I saw the aircraft was headed directly to the concrete revetment on the south bank of Bear Creek. I banked the aircraft left, striking the water nose down and with a left bank." A representative of the recovery company forwarded pictures of the airplane during recovery. The fuel selector was positioned on the both position and the throttle, mixture, and carburetor heat controls were in their forward positions. A National Transportation Safety Board investigator and a technical representative from the engine manufacturer examined the wreckage at a salvage yard. The airplane was at the salvage yard for several weeks before the examination. The engine oil dip stick was removed, and water flowed from the dip stick tube. A visual inspection of the motor was conducted, other than evidence of water submersion, no obvious abnormalities were noted. The engine was not free to rotate. However, after removing water from the cylinders, the engine rotated freely. The sound of the magneto impulse couplings were noted. The engine oil was drained from the sump and appeared to be a mixture of oil and water. The removed sparkplugs appeared wet from water. A thumb compression test was completed on each cylinder; suction and compression were present on each cylinder. Each cylinder was inspected via borescope and no preimpact abnormalities were observed. Both left and right magnetos, and the carburetor were removed from the engine. The magnetos were rotated by an impact driver; spark was observed on each terminal, for both magnetos. The carburetor finger screen was not contaminated. The carburetor bowl contained a dirty-brown liquid and when tested with water-detecting pasted; tested positive for water. A small amount of liquid, consistent with aviation fuel, was present in the accelerator pump section of the carburetor. No preimpactmechanical anomalies were found during the engine examination. At 0915, the recorded weather at the Houston Executive Airport, near Houston, Texas, was: Wind calm; visibility 10 statute miles; sky condition clear; temperature 18° C; dew point 16° C; altimeter 30.10 inches of mercury. At 0853, the recorded weather at the David Wayne Hooks Memorial Airport, near Houston, Texas, was: Wind calm; visibility 9 statute miles; sky condition clear; temperature 15° C; dew point 15° C; altimeter 30.08 inches of mercury. At 0853, the recorded weather at the Sugar Land Regional Airport, near Houston, Texas, was: Wind calm; visibility 10 statute miles; sky condition clear; temperature 16° C; dew point 14° C; altimeter 30.08 inches of mercury. The recorded local temperature and dew point data near the time of the engine power loss was plotted on a carburetor icing chart. The charted data showed that the weather in the area was conducive to serious icing at any power to moderate icing at cruise power/serious icing at descent power. The Pilot's Handbook of Aeronautical Knowledge, in part, states: When conditions are conducive to carburetor icing during flight, periodic checks should be made to detect its presence. If detected, full carburetor heat should be applied immediately, and it should be left in the ON position until you are certain that all the ice has been removed. If ice is present, applying partial heat or leaving heat on for an insufficient time might aggravate the situation. In extreme cases of carburetor icing, even after the ice has been removed, full carburetor heat should be used to prevent further ice formation. A carburetor temperature gauge, if installed, is very useful in determining when to use carburetor heat. ## Aircraft - Registration: N3973L (not matched to a registry record) - Reported make and model: CESSNA 172 (G) - Category: Airplane - Serial number: 17254142 - Year built: 1966 - Airframe hours: 3006.8 - Engines: Continental O-300-D 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 20, 2018 - Departed: IWS, Houston, TX - Destination: IWS, Houston, TX - Airport: IWS, West Houston, runway 15, 3,953 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 83; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 3, with waivers/limitations; last flight review January 29, 2017; seat: left; restraint: 3-point; flight hours: 6,300 total, 1,500 in this make and model, 5,500 as pilot in command, 17 in the last 90 days, 2 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: 64 °F, dew point 61 °F - Altimeter: 30.10 inHg - Observed at: KTME, 12 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 20181027024789A](https://openairdocs.org/incident/20181027024789A), Oct 27, 2018: Cessna 172G, Houston, TX, Destroyed. On short final the engine lost power. The pilot did not have the carburetor heat on at the time. He then applied the heat and the engine loss more power so he… ## Docket (8 files) The files NTSB released with the investigation on January 30, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98552. 3.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 426 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469900&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Powerplants - Statement From C. Hatch (item 2, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469901&FileExtension=.PDF&FileName=Powerplants%20-%20Statement%20From%20C.%20Hatch-Master.PDF - Weather Reports and Records (item 3, .PDF, 61 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469902&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - Miscellaneous Information - Carburetor Icing Charts Using Surronding Airport Wx Data (item 4, .PDF, 184 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469903&FileExtension=.PDF&FileName=Miscellaneous%20Information%20-%20Carburetor%20Icing%20Charts%20Using%20Surronding%20Airport%20Wx%20Data-Master.PDF - Statement of Party Representatives to NTSB Investigation - Continental (item 5, .PDF, 593 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469904&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation%20-%20Continental-Master.PDF - Photos During Engine Examination (item 6, .PDF, 9 photos, 966 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469905&FileExtension=.PDF&FileName=Photos%20During%20Engine%20Examination-Master.PDF - Photos During Recovery - Supplied By Recovery Personnel (item 7, .PDF, 9 photos, 702 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40470015&FileExtension=.PDF&FileName=Photos%20During%20Recovery%20-%20Supplied%20By%20Recovery%20Personnel-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 8, .PDF, 188 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469906&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.