# NTSB WPR10LA123: Cessna 172, N8959B, Pahrump, NV, January 30, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 30, 2010, 09:45 local (17:45 UTC) - Place: Pahrump, NV - Coordinates: 36.066665, -115.808334 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.0667&lon=-115.8083&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 19, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 75321 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10LA123 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75321/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75321 - Page: https://openairdocs.org/ntsb/WPR10LA123 ## Probable cause Fuel starvation as a result of the improper installation of the carburetor float valve by unknown personnel. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Maintenance/inspections](https://openairdocs.org/ntsb-findings/01010500): Aircraft › Aircraft handling/service · Incorrect service/maintenance (probable cause); cases with it: [Cessna 172, 1 case](https://openairdocs.org/ntsb-findings/01010500/cases.md?model=2072402), [All aircraft, 103 cases](https://openairdocs.org/ntsb-findings/01010500/cases.md) - [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Cessna 172, 2 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=2072402), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Other (probable cause); cases with it: [Cessna 172, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=2072402), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/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) (defining event); cases with it: [Cessna 172, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072402), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 172, 10 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072402), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 172, 11 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072402), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that about 10-15 minutes after departure he heard three loud "pops" and the engine rpm dropped to about 1200. The pilot attempted to restart the engine by adjusting the fuel selector, mixture, and throttle, but was unsuccessful. The pilot initiated a forced landing to desert terrain. As the airplane touched down, the nose landing gear sunk into the ground and the airplane nosed over and came to rest inverted. A postaccident examination of the engine by a Federal Aviation Administration inspector revealed that the carburetor float valve was improperly installed, which restricted fuel flow to the engine. According to a Continental Motors representative, the carburetor overhaul requirements were the same as specified for the engine; 10 to 12 years since placed in service or last overhauled, whichever comes first. A review of the aircraft logbooks revealed no entries pertaining to the maintenance or overhaul of the carburetor. ## Factual narrative On January 30, 2010, about 0945 Pacific standard time, a Cessna 172U, N8959B, experienced a loss of engine power during cruise flight and the pilot made a forced landing in the vicinity of a landing strip in the desert near Pahrump, Nevada. Chapter 163 Flying Club operated the personal cross-country flight under the provisions of Title 14 Code of Federal Regulation Part 91. The certified private pilot and one passenger were not injured. The airplane sustained structural damage to the tail section. Visual meteorological conditions prevailed for the flight that departed the Shoshone Airport (L61), Shoshone, California, at 0930. The flight was destined for North Las Vegas Airport (VGT), Las Vegas, Nevada, and no flight plan had been filed. In a written statement, the pilot reported that about 10-15 minutes after departure he heard three loud "pops" and the engine rpm dropped to about 1200 rpm. The pilot attempted to restart the engine by adjusting the fuel selector, mixture, and throttle, but was unsuccessful. The pilot initiated a forced landing to desert terrain. As the airplane touched down, the nose landing gear sunk into the soft ground, and the airplane nosed over and came to rest inverted. During a post accident examination of the engine by a Federal Aviation Administration (FAA) inspector, the carburetor was removed from the engine and disassembled. The fuel inlet screen was removed. The FAA inspector reported that fine sand and pebbles consistent with an impact with the ground were observed. The FAA inspector further reported that carburetor bowl was removed and the float valve was found to be improperly installed. A review of the airplane's maintenance logbooks revealed that the airplane's most recent inspection, an annual inspection, occurred on February 27, 2009. The most recent engine overhaul occurred in February 2004. Maintenance conducted on the carburetor or fuel system was not mentioned in the logbook entries. A representative from Continental Motors reported that the time between overhaul for a carburetor is the same as specified by the engine manufacturer; 10 to 12 years since placed in service or overhaul, whichever comes first. ## Aircraft - Registration: [N8959B](https://openairdocs.org/deregistered/N8959B-2017-09-26), registration cancelled 2017-09-26, S/N 36659, built 1958 (OpenAirDocs) - Reported make and model: CESSNA 172 (U) - Registry model: [Cessna 172](https://openairdocs.org/model/cessna-172) (registry code 2072402) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 36659 - Airframe hours: 3884 - Engines: Continental Motors O-300 140 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Chapter 163 Flying Club - Registered owner: Chapter 163 Flying Club - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: Annual, February 27, 2009 - Departed: L61, Shoshone Airpor, CA - Destination: VGT, Las Vegas, NV - Airport: VGT, North Las Vegas Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review August 13, 2009; seat: left; flight hours: 143 total, 143 in this make and model, 72 as pilot in command, 22 in the last 90 days, 3 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 50 °F, dew point 34 °F - Altimeter: 30.00 inHg - Observed at: VGT, 40 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 20100130027349A](https://openairdocs.org/incident/20100130027349A), Jan 30, 2010: Cessna 172, Pahrump, NV, Substantial damage. Pilot and one passenger departed vgt at approximately 0715 hours for L61 (shoshone). Aircraft had full fuel load. Landed safely at shoshone (L61) after… ## Docket (6 files) The files NTSB released with the investigation on July 20, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75321. 1.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 558 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40347180&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Reports from State Agencies - Sheriff's Office (item 2, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40347181&FileExtension=.PDF&FileName=Reports%20from%20State%20Agencies%20-%20Sheriff%27s%20Office-Redacted.PDF - Record of Conversation: FAA Inspector (item 3, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351293&FileExtension=.PDF&FileName=Record%20of%20Conversation%3A%20FAA%20Inspector-Master.PDF - Record of Conversation with Continental Motor's Inc. (item 4, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353762&FileExtension=.PDF&FileName=Record%20of%20Conversation%20with%20Continental%20Motor%27s%20Inc.-Master.PDF - Maintenance Logbook: Most Recent Inspection (item 5, .PDF, 314 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40349611&FileExtension=.PDF&FileName=Maintenance%20Logbook%3A%20Most%20Recent%20Inspection-Redacted.PDF - Maintenance Logbook: Most Recent Overhaul (item 6, .PDF, 335 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40349610&FileExtension=.PDF&FileName=Maintenance%20Logbook%3A%20Most%20Recent%20Overhaul-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.