# NTSB WPR09LA122: Cessna 172N, N6443E, Big Bear Lake, CA, February 20, 2009 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: February 20, 2009, 12:00 local (20:00 UTC) - Place: Big Bear Lake, CA - Coordinates: 34.241664, -117.015274 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.2417&lon=-117.0153&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report November 9, 2009 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration FSDO - NTSB case key (mKey): 73376 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA122 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73376/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73376 - Page: https://openairdocs.org/ntsb/WPR09LA122 ## Probable cause The pilot's failure to maintain clearance from terrain while maneuvering in a ravine. Contributing to the accident was the pilot's decision to continue flight in an area that exceeded the climb rate capabilities of the airplane. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Cessna 172N, 6 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=2072434), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 172N, 41 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2072434), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Performance/control parameters: climb rate](https://openairdocs.org/ntsb-findings/01062035): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Cessna 172N, 4 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md?model=2072434), [All aircraft, 265 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [Cessna 172N, 8 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=2072434), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120) (defining event); cases with it: [Cessna 172N, 14 cases](https://openairdocs.org/ntsb-events/120/sequence.md?model=2072434), [All aircraft, 1,074 cases](https://openairdocs.org/ntsb-events/120/sequence.md) ## Analysis After completing some practice maneuvers at an altitude of about 6,000 feet mean sea level, the pilot proceeded towards an airport located in mountainous terrain. The destination airport elevation was 6,752 feet and elevations in the area exceeded 8,000 feet. The pilot reported that as he flew into a ravine, he established a climbing attitude, but observed no change in altitude. The pilot continued flight into the ravine and noted that the airplane started to lose altitude. He then attempted to turn around and initiated a left-hand turn. However, as the airplane's indicated airspeed was about 50 knots and the airplane was close to the terrain, the pilot soon "realized he was not going to make it." He "aimed for the area with the least amount of trees," and the airplane impacted terrain approximately 8 miles from the destination airport at an elevation of about 6,100 feet. Although the pilot reported finding water in the fuel tanks during his preflight inspection, he did not report that the engine displayed any of the symptoms of water contamination such as running rough, momentary power interruptions, or fluctuations in power. Near the time of the accident, the calculated density altitude at the destination airport was 7,725 feet. ## Factual narrative On February 20, 2009, about 1200 Pacific standard time, a Cessna 172N, N6443E, collided with terrain while maneuvering in mountainous terrain near Big Bear Lake, California. The private pilot and the passenger received minor injuries. The airplane, which was registered to a private individual and operated by the pilot, sustained substantial damage. Visual meteorological conditions prevailed for the personal cross-country flight conducted under Title 14 Code of Federal Regulations Part 91, and no flight plan was filed. The flight originated from the San Bernardino International Airport, San Bernardino, California, at 1115, with an intended destination of the Big Bear City Airport, Big Bear, California. The pilot reported that during the preflight inspection, he drained a total of about 18 ounces of water from the wing fuel tanks. He then added fuel to each wing tank, rocked the wings by hand, drained the tanks and fuel strainer again, and found no water. Following departure, he climbed to about 6,000 feet mean sea level (msl) and conducted a series of practice flight maneuvers for his commercial pilot's license. After completing the maneuvers, the pilot departed the practice area to the northeast towards Big Bear City Airport. The pilot's route of flight to the airport took the airplane over mountainous terrain with elevations above 8,000 feet. He planned to fly up a ravine, and over the dam at the west end of Big Bear Lake. As the airplane entered the ravine he "put the plane in a climbing attitude, although the indicated airspeed lowered – the altitude remained the same." As the pilot flew further into the ravine he "was forced to lower [the airplane's] nose to maintain best angle of climb speed. As I lowered [the] nose I began to lose altitude." The pilot applied carburetor heat as he thought the engine might be experiencing carburetor icing. After observing a slight decrease in engine rpm, the pilot realized carburetor ice was not an issue and turned off the carburetor heat. The pilot then observed an area where he thought he "would have sufficient room to turn around" and initiated a left turn. However, as the "indicated airspeed was near 50 knots and [the airplane] was getting closer to the treetops," the pilot was "only able to complete 90 degrees of turn" before he "realized he was not going to make it." He "aimed for the area with the least amount of trees," and the airplane impacted terrain approximately 2 miles west of Big Bear Lake Dam at an elevation of about 6,100 feet. Review of photographs supplied by the airplane owner revealed that the leading edge of the right wing was buckled and crushed aft. The inboard portion of the left wing and flap exhibited severe deformation. The nearest weather reporting station to the accident site was located about 8 miles west of the accident site at Big Bear City Airport, elevation 6,752 feet. At 1210, this station was reporting wind 270 degrees at 5 knots; visibility 10 miles; skies clear;temperature 12 degrees Celsius (C); dew point -16 degrees C; and altimeter setting 30.20 inches of mercury. The calculated density altitude at the airport was 7,725 feet. ## Aircraft - Registration: [N6443E](https://openairdocs.org/deregistered/N6443E-2013-04-29), registration cancelled 2013-04-29, S/N 17272020, built 1978 (OpenAirDocs) - Reported make and model: CESSNA 172N - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17272020 - Airframe hours: 14070 - Engines: LYCOMING O-320 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, May 21, 2008, 90 hours before - Departed: SBD, San Bernardino, CA - Destination: L35, Big Bear, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 20; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review January 20, 2009; seat: left; flight hours: 256 total, 130 in this make and model, 154 as pilot in command, 20 in the last 90 days, 3 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 3 °F - Altimeter: 30.20 inHg - Observed at: L35, 7 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 20090220004019A](https://openairdocs.org/incident/20090220004019A), Feb 20, 2009: Cessna 172N, Big Bear, CA, Substantial damage. (-23) On 02/20/2009 at approximately 11:15 hours PST the pilot and airplane departed san bernardio airport (sbd) on a personal/pleasure flight with one… ## Docket (3 files) The files NTSB released with the investigation on August 31, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73376. 892 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 757 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40315228&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Reports and Records (item 2, .PDF, 91 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40315229&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - FAA Inspector's Report of Pilot Interview (item 3, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40315230&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Report%20of%20Pilot%20Interview-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.