# NTSB WPR21LA348: Cessna 172N, N4977G, Grass Valley, CA, September 19, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: September 19, 2021, 15:30 local (22:30 UTC) - Place: Grass Valley, CA - Coordinates: 39.224056, -121.00255 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.2241&lon=-121.0025&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - NTSB case key (mKey): 103912 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA348 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103912/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103912 - Page: https://openairdocs.org/ntsb/WPR21LA348 ## Probable cause The pilot’s failure to attain a proper touchdown point on the runway while landing in gusting wind conditions, which resulted in a runway overrun. Contributing to the accident was the pilot’s distraction due to an electrical issue. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Communications system](https://openairdocs.org/ntsb-findings/01022300): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Cessna 172N, 1 case](https://openairdocs.org/ntsb-findings/01022300/cases.md?model=2072434), [All aircraft, 7 cases](https://openairdocs.org/ntsb-findings/01022300/cases.md) - [Personality/attitude: motivation/respond to pressure](https://openairdocs.org/ntsb-findings/02021025): Personnel issues › Psychological · Pilot; cases with it: [Cessna 172N, 3 cases](https://openairdocs.org/ntsb-findings/02021025/cases.md?model=2072434), [All aircraft, 53 cases](https://openairdocs.org/ntsb-findings/02021025/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: descent/approach/glide path](https://openairdocs.org/ntsb-findings/01062040): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Cessna 172N, 16 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md?model=2072434), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Cessna 172N, 28 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=2072434), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Electrical system malf/failure](https://openairdocs.org/ntsb-events/332); cases with it: [Cessna 172N, 1 case](https://openairdocs.org/ntsb-events/332/sequence.md?model=2072434), [All aircraft, 182 cases](https://openairdocs.org/ntsb-events/332/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Cessna 172N, 18 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=2072434), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported that, he departed normally to fly the airport traffic pattern. After he turned to the base leg of the traffic pattern, he observed a low voltage indication on the annunciator panel and was unable to announce his base turn on the radio. The pilot then turned to the final approach leg of the traffic pattern without making the announcement on the radio and added three notches of flaps. He experienced “windshear” near the runway threshold and the airplane briefly ascended. The pilot attempted to regain his glide path by extending full flaps and the airplane floated down the runway. At the time he was concerned about climbing out, so he elected to continue the landing instead of performing a go-around. After the airplane eventually touched down on the runway, the pilot applied full braking, but the airplane skidded off the runway edge into a ditch, which resulted in substantial damage to the right wing. According to the pilot, he misjudged the landing distance and landed long to salvage the landing instead of attempting a go-around. He further remarked that the electrical issue affected his radio and prevented him from announcing his base and final turns in the airport traffic pattern, which may have influenced his decision to land promptly. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N4977G](https://openairdocs.org/deregistered/N4977G-2022-07-30), registration cancelled 2022-07-30, S/N 17273524, built 1979 (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: 17273524 - Year built: 1979 - Airframe hours: 3491 - Engines: Lycoming O-320-H2BD 160 hp reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 17, 2021, 1 hours before - Destination: Same as departure - Airport: GOO, Nevada County, runway 07/25, 4,657 × 75 ft, asphalt - Equipment: ADS-B, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review January 7, 2021; seat: left; restraint: 3-point; flight hours: 293 total, 243 in this make and model, 47.31 as pilot in command, 0.4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 0° at 0 knots, gusting 11 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 43 °F - Altimeter: 30.10 inHg - Observed at: KGOO - METAR: KGOO 192235Z AUTO 00000G11KT 10SM CLR 19/06 A3010 RMK A01 ## 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 20210919021229A](https://openairdocs.org/incident/20210919021229A), Sep 19, 2021: Cessna 172N, Grass Valley, CA, Substantial damage. The pilot was on his first flight of the day performing pattern work. The pilot mentioned on an interview by phone on November 10, 2021 at approximately 3:15… ## Docket (4 files) The files NTSB released with the investigation on October 12, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103912. 6.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 4.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12777283&FileExtension=pdf&FileName=Misc%204977G%20NTSB%20Safetly%20Bd%20Accid%20Report%20Filled%20Signed_Redacted-Rel.pdf - Correspondence with accident pilot (item 2, PDF, 3 pages, 142 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12777200&FileExtension=pdf&FileName=Correspondence%20with%20accident%20pilot_Redacted-Rel.pdf - Record of conversation, accident pilot (item 3, PDF, 1 page, 125 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12786602&FileExtension=pdf&FileName=Record%20of%20Conversation%20Pilot-Rel.pdf - Accident photograph (item 4, PDF, 1 page, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12786148&FileExtension=pdf&FileName=Accident%20Photographs-Rel.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.