# NTSB WPR09LA179: Cessna 182, N6433A, Kalispell, MT, April 4, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 4, 2009, 15:21 local (21:21 UTC) - Place: Kalispell, MT - Coordinates: 48.310554, -114.256385 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.3106&lon=-114.2564&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR go-around: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 19, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 73602 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA179 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73602/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73602 - Page: https://openairdocs.org/ntsb/WPR09LA179 ## Probable cause A partial loss of engine power during a go-around for undetermined reasons. Contributing to the accident was a fatigue failure of the right main landing gear spring. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: main gear strut/axle/truck](https://openairdocs.org/ntsb-findings/01023213): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna 182, 2 cases](https://openairdocs.org/ntsb-findings/01023213/cases.md?model=2072702), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01023213/cases.md) - [Terrain: snowy/icy terrain](https://openairdocs.org/ntsb-findings/03021030): Environmental issues › Physical environment · Effect on equipment; cases with it: [Cessna 182, 1 case](https://openairdocs.org/ntsb-findings/03021030/cases.md?model=2072702), [All aircraft, 77 cases](https://openairdocs.org/ntsb-findings/03021030/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 182, 5 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2072702), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Cessna 182, 3 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2072702), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Approach-VFR go-around: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 182, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072702), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-landing roll: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 182, 10 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072702), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 182, 8 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072702), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The airplane used for the skydiving operation was equipped with a foot step just above the right wheel, which the skydivers used to launch from the airplane. As the last of four skydivers stepped on the foot step, the right main landing gear fell away. The pilot reported that after he flew around for about 1 1/2 hours to burn off fuel, he intended to perform a low pass over the runway before coming around to land. The carburetor heat was turned on during the descent and, as he applied power to go around at midfield, the engine sputtered and lost partial power. The airplane was about 20 feet above ground level and he was able to maintain that altitude past the runway end before landing off the runway surface on snowy terrain. The airplane subsequently nosed over and came to rest inverted, sustaining substantial damage to both wings and the empennage. The carburetor heat was found in the “off” position; however, the investigation did not determine if the pilot turned off the carburetor heat or if it was pushed in by impact forces. Examination of the main landing gear revealed a fracture originating at the forward upper surface spring. The fracture surface displayed features indicative of fatigue cracking; the depth of the cracking was approximately 0.11 inches. An examination of the engine and carburetor revealed no anomalies that could account for the loss of partial power. The meteorological conditions were not conducive to carburetor icing. ## Factual narrative HISTORY OF FLIGHT On April 4, 2009, at 1521 mountain daylight time, a Cessna 182, N6433A, nosed over during an off airport forced landing at Carson Field Airport, Kalispell, Montana. The owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The certificated commercial pilot was not injured; the airplane sustained substantial damage to the wings and empennage. The local skydiving flight departed Kalispell City Airport about 1330. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot departed with four skydivers on board. The airplane was equipped with a foot step just above the right wheel, which the skydivers used to launch from the airplane. They flew to the jump zone, and as the last skydiver stepped on the foot step, the right main landing gear fell away. After flying about 1 1/2 hours to burn off fuel prior to landing, the pilot elected to divert to the airplane’s home base at Carson Field. He reported that he intended to perform a low pass, and then come around for landing. He stated that he overshot the runway centerline, and used a slip maneuver to get back into position. He stated that he had the carburetor heat turned on during the descent. As he applied power to go around, the engine sputtered in a fashion that he described as just like carburetor ice. METEOROLOGICAL INFORMATION An aviation routine weather report (METAR) for Kalispell was issued at 1455 MDT. It stated: winds calm; visibility 10 miles; skies, few at 5,000 feet; temperature 9/48 degrees Celsius/Fahrenheit; dew point -7/19 degrees Celsius/Fahrenheit; altimeter 30.25 inches of mercury. The relative humidity was 32 percent. The weather conditions were plotted on the chart for the probability of carburetor icing depicted in FAA Special Airworthiness Information Bulletin (SAIB) CE-09-35. Their location fell outside the probability range for icing. ADDITIONAL INFORMATION WITNESS OBSERVATION A Safety Board investigator observed the accident. He heard the pilot apply power midfield at an estimated altitude of 20 feet above ground level (agl); the engine sputtered and the airplane maintained altitude. He continued to observe it fly at the same altitude past the runway end, sputtering intermittently, and then out of his view behind a hill. He did not observe any smoke or vapors emitting from the airplane. The airplane touched down off the runway surface on snowy terrain. It nosed over and came to rest inverted sustaining substantial damage to both wings and the empennage. The right main landing gear separated just inside the airframe. The fracture surface was flat, and granular in appearance. The investigator observed fuel leaking from the fuel caps after the accident, although the position of the airplane prevented an accurate assessment of the total fuel onboard. He observed fuel in the firewall mounted gascolator. The fuel had the appearance and smell of automobile gasoline. He noted that thefuel selector valve was in the off position, and the carburetor heat, fuel mixture, propeller, and throttle controls were in the full forward position. He confirmed that the carburetor heat control was continuous from the cabin through to the flapper located within the carburetor mounted heat box. METALURGICAL EXAMINATION Cessna examined the fractured right main landing gear (MLG) spring, part number 0741009-4, and the Safety Board Material’s Laboratory concurred with their findings. The fracture origin was at the forward upper surface of the MLG spring. They noted a chevron pattern on the fracture surface. Mechanical damage obscured any surface imperfections that may have been present prior to the fracture. Under high magnification, the fracture surface showed features indicative of fatigue cracking; the depth of the cracking was approximately 0.11 inches. ENGINE EXAMINATION An engine repair facility disassembled and examined the engine. They discovered no defects with the engine or carburetor. They reassembled the engine, and reinstalled the carburetor. During a ground test run, they stated that the engine and carburetor functioned properly. ## Aircraft - Registration: [N6433A](https://openairdocs.org/aircraft/N6433A), registered now, S/N 33233 (OpenAirDocs) - Reported make and model: CESSNA 182 - Registry model: [Cessna 182](https://openairdocs.org/model/cessna-182) (registry code 2072702) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 33233 - Airframe hours: 6859 - Engines: Teledyne Continental Motors O-470-S 230 horsepower reciprocating - Damage: Substantial damage - Flight: Skydiving, Part 91 - Operator: Fred Sand - Registered owner: Fred Sand - Airworthiness certificate: Standard, Normal - Departed: S27, Kalispell, MT - Destination: MT53, Kalispell, MT - Airport: MT53, Carson Field Airport, runway 14, 3,660 × 40 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review June 22, 2007; seat: left; flight hours: 894 total, 366 in this make and model, 10 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 19 °F - Altimeter: 30.00 inHg - Observed at: GPI, 30 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 20090404003359A](https://openairdocs.org/incident/20090404003359A), Apr 4, 2009: Cessna 182, Kalispell, MT, Substantial damage. (-23) On April 4, 2009, at 1521 mountain time, a Cessna 182, N6433A, registered [privacy data omitted], flipped over in a field after the engine failed while… ## Docket (5 files) The files NTSB released with the investigation on March 15, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73602. 1.6 MB in all. - NTSB Investigator Observations and Examination Notes (item 1, .PDF, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344483&FileExtension=.PDF&FileName=NTSB%20Investigator%20Observations%20and%20Examination%20Notes-Master.PDF - Cessna Approval to Use Lab Report in Public Docket (item 2, .PDF, 39 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40335640&FileExtension=.PDF&FileName=Cessna%20Approval%20to%20Use%20Lab%20Report%20in%20Public%20Docket-Master.PDF - Cessna Letter Reference Export Compliance (item 3, .PDF, 372 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344484&FileExtension=.PDF&FileName=Cessna%20Letter%20Reference%20Export%20Compliance-Redacted.PDF - Cessna Materials Lab Report (item 4, .PDF, 888 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40333542&FileExtension=.PDF&FileName=Cessna%20Materials%20Lab%20Report-Master.PDF - Engine Examination Report (item 5, .PDF, 212 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40333543&FileExtension=.PDF&FileName=Engine%20Examination%20Report-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.