# NTSB WPR11LA463: Cessna 177, N3152T, Rock Springs, WY, September 23, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 23, 2011, 10:05 local (16:05 UTC) - Place: Rock Springs, WY - Coordinates: 41.588333, -109.026664 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.5883&lon=-109.0267&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 24, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 81879 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA463 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81879/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81879 - Page: https://openairdocs.org/ntsb/WPR11LA463 ## Probable cause The pilot did not lean the fuel mixture prior to takeoff, which resulted in the engine's inability to attain sufficient power due to the rich mixture, and his inadequate preflight planning. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Planning/preparation: flight planning/navigation](https://openairdocs.org/ntsb-findings/02061025): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 177, 1 case](https://openairdocs.org/ntsb-findings/02061025/cases.md?model=2073704), [All aircraft, 179 cases](https://openairdocs.org/ntsb-findings/02061025/cases.md) - [Engine fuel and control: fuel controlling system](https://openairdocs.org/ntsb-findings/01057320): Aircraft › Aircraft power plant · Incorrect use/operation (probable cause); cases with it: [Cessna 177, 1 case](https://openairdocs.org/ntsb-findings/01057320/cases.md?model=2073704), [All aircraft, 59 cases](https://openairdocs.org/ntsb-findings/01057320/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; cases with it: [Cessna 177, 4 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=2073704), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/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: [Cessna 177, 3 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=2073704), [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. - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 177, 6 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2073704), [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 177, 17 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073704), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 177, 28 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2073704), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the pilot, he leaned the mixture in order to start the engine, but he did not lean the mixture prior to takeoff and did not remember using the Before Takeoff checklist. Shortly after takeoff and during the initial climb, the engine power was smooth and strong, but, about 500 feet above ground level, the engine started vibrating and the airplane began to lose altitude. Not being able to return to the airport, the pilot made an emergency off-field landing. During the landing roll, the left main landing gear impacted a hole or a berm, which resulted in the collapse of the left main gear. A postaccident engine run revealed no anomalies with the engine that would have precluded normal operation. The airplane’s owner’s manual notes that, for maximum rate-of-climb performance at airports above 5,000 feet, the mixture control should be leaned. The elevation of the airport was 6,764 feet. The density altitude at the time of the accident was calculated to be 7,907 feet. ## Factual narrative On September 23, 2011, about 1005 mountain daylight time, a 1968 Cessna 177 airplane, N3152T, was substantially damaged following a forced landing after a partial loss of engine power near Rock Springs, Wyoming. The certified airline transport pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed at the time of the accident. The cross-country flight was being operated in accordance with 14 Code of Federal Regulations Part 91, and a flight plan was not filed. The flight departed the Rock Springs-Sweetwater County Airport (RKS), Rock Springs, Wyoming, about 0955, with a planned destination of Alva, Oklahoma. In a written statement submitted to the National Transportation Safety Board investigator-in-charge (IIC), as well as in a telephone conversation with the IIC, the pilot reported that he had to lean the mixture to start the engine, but did not remember readjusting the mixture control prior to takeoff, nor did he remember using the airplane’s Before Takeoff checklist prior to takeoff. The pilot further reported that during the engine runup prior to departure he observed that both magnetos dropped 50 RPM, and that he cycled the propeller three times, and each time the propeller recovered in a normal time span of between 3 to 5 seconds. He stated that the engine was strong and smooth on takeoff and climb, but about 500 feet above ground level when he began a right hand turn, the engine began to vibrate and the airplane started to lose altitude. The pilot reported that as he was unable to maintain altitude, he elected to make a forced landing to a draw. During the landing roll the airplane impacted either a hole or a berm with the left main landing gear, which resulted in the left landing gear to collapse. The airplane sustained substantial damage to the outboard section of both wings. At the request of the IIC, a National Transportation Safety Board senior air safety investigator conducted a post-accident run of the airplane’s engine at the facilities of Beegles Aircraft Services, Greeley, Colorado on October 18, 2011. The investigator reported that the engine started immediately, ran smoothly for about 5 minutes, and responded to all throttle movements and cycling of the propeller. Both magnetos were checked, with barely a detectable drop on each. The investigator added that on engine shutdown there was a slight RPM increase as the mixture was leaned, which was to be expected. The investigator reported no anomalies with the engine that would have precluded normal operation. At 0954, the weather reporting facility located at RKS reported wind 290 degrees at 5 knots, visibility 10 miles, temperature 16 degrees Celsius (C), dew point -2 degrees C, and an altimeter setting of 30.45 inches of Mercury. The density altitude at the time of the accident was calculated to be 7,907 feet. The 1968 Cessna 177 Owner’s Manual, which addresses Maximum Rate-of-Climb Data in the performance section, states under Note #1 - Flaps up,full throttle and mixture leaned for smooth operation above 5,000 ft. The elevation of the Rock Springs-Sweetwater County Airport is 6,764 feet mean sea level. ## Aircraft - Registration: [N3152T](https://openairdocs.org/deregistered/N3152T-2012-01-17), registration cancelled 2012-01-17, S/N 17700452, built 1967 (OpenAirDocs) - Reported make and model: CESSNA 177 (UNDESIGNAT) - Registry model: [Cessna 177](https://openairdocs.org/model/cessna-177) (registry code 2073704) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17700452 - Airframe hours: 2947 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Phillip M. Prigmore - Registered owner: Prigmore Aviation Services LLC - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: Annual, May 26, 2011 - Departed: RKS, Rock Springs, WY - Destination: AVK, Alva, OK - Airport: RKS, Rock Springs Airport, runway 27, 10,000 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; last flight review December 5, 2010; seat: left; flight hours: 9,913 total, 7 in this make and model, 7,555 as pilot in command, 58 in the last 90 days, 25 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 28 °F - Altimeter: 30.45 inHg - Observed at: RKS, 1 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 20110923023639A](https://openairdocs.org/incident/20110923023639A), Sep 23, 2011: Cessna 177, Rock Springs, WY, Substantial damage. On September 23rd, 2011 at approximately 10:05 MDT, N3152T, a Cessna model 177 aircraft sustained substantial damage during an off field landing after… ## Other investigations on N3152T (1) 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. - [NTSB OAK70FXQ17](https://openairdocs.org/ntsb/OAK70FXQ17), Jun 20, 1970: Cessna 177 (N3152T), Reno, NV, substantial damage ## Docket (10 files) The files NTSB released with the investigation on March 21, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81879. 1.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 824 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363492&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Data (item 2, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363493&FileExtension=.PDF&FileName=Weather%20Data-Master.PDF - FAA Inspector's Report (item 3, .PDF, 131 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363494&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Report-Redacted.PDF - Post-Accident Engine Run Report (item 4, .PDF, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363495&FileExtension=.PDF&FileName=Post-Accident%20Engine%20Run%20Report-Master.PDF - Excerpts from 1968 Cessna 177 Owner's Manual (item 5, .PDF, 199 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363496&FileExtension=.PDF&FileName=Excerpts%20from%201968%20Cessna%20177%20Owner%27s%20Manual-Master.PDF - Record of Conversation (Pilot-in-Command) (item 6, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363497&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(Pilot-in-Command)-Master.PDF - Excerpts from Cessna Service Letter (SNL 94-6) (item 7, .PDF, 116 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363500&FileExtension=.PDF&FileName=Excerpts%20from%20Cessna%20Service%20Letter%20(SNL%2094-6)-Master.PDF - Fuel Receipt (item 8, .PDF, 86 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40364435&FileExtension=.PDF&FileName=Fuel%20Receipt-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 9, .PDF, 249 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363498&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 10, .PDF, 35 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363499&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.