# NTSB WPR18LA047: Cessna 172D, N2351U, Auburn, WA, December 7, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: December 6, 2017, 16:00 local (Dec 7, 2017, 00:00 UTC) - Place: Auburn, WA - Coordinates: 47.330001, -122.2275 - Nearby events: https://openairdocs.org/map.md?lat=47.3300&lon=-122.2275&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Adminsitration - NTSB case key (mKey): 96477 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA047 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96477/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96477 - Page: https://openairdocs.org/ntsb/WPR18LA047 ## Probable cause The pilot's loss of airplane control for reasons that could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 172D, 4 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2072410), [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. - [Approach-VFR pattern final: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333); cases with it: [Cessna 172D, 1 case](https://openairdocs.org/ntsb-events/333/sequence.md?model=2072410), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) - [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Cessna 172D, 5 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2072410), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Approach-VFR pattern final: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 172D, 11 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072410), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that the airplane yawed right, and he experienced a loss of aileron control effectiveness while on final approach for landing. He applied engine power to go around, which he perceived to worsen the problem, then chose to reduce power and land. The airplane touched down on the runway about 45° off runway heading, continued off the runway, and impacted a water retention pond. Examination of the aileron flight control system revealed no evidence of a mechanical failure or malfunction. There was evidence that the right wing contacted the runway during landing, and aileron control cable tension could not be measured due to the damage to the wing. The reason for the reported aileron flight control malfunction could not be determined. ## Factual narrative On December 7, 2017, about 1600 Pacific standard time, a Cessna 172D, N2351U, was substantially damaged when it was involved in an accident near Auburn, Washington. The private pilot was not injured. The airplane was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, after turning onto the final approach leg of the airport traffic pattern for landing, he set the flaps to 30° at an airspeed of 70 miles per hour. About 20 to 25 seconds later, the airplane's nose veered sharply to the left without any control input. The pilot stated that he counteracted the movement by applying right rudder and the airplane veered to the right as he noticed that he had no response from left aileron control input. The pilot reported that he tried to stabilize the airplane with rudder inputs and performed a go-around by applying power. As he added engine power, he noticed that the lack of response from the ailerons became more pronounced and decided to reduce power and land. The airplane subsequently touched down briefly on the runway surface, about 45 degrees off runway heading, before it exited the right side of the runway and impacted a water retention pond. The airplane came to rest upright in a nose-low attitude. Both wings remained attached to the fuselage via their respective mounts. The right wing exhibited buckling from about mid-span of the flap inboard to the wing root. The wing was measured along the rear spar from the root to the wing tip and the right wing was found to be about 3/4 inch shorter than the left, consistent with the buckling damage in the right wing. The right-wing fiberglass tip was separated and exhibited scraping along the trailing edge, exposing the material beneath the paint. The wing exhibited scraping on the bottom side where the fiberglass wing tip attaches to the wing structure. No evidence of any preexisting mechanical malfunction was observed with the airplane. Control yoke inputs resulted in minimal movement of the ailerons. The control cables from the control chains were continuous from the control column chains throughout the airframe to the left and right aileron bellcranks. The balance cable remained attached to both aileron bellcranks. All control cable pulleys remained secure at their respective mounts with the aileron control cables still within the grooves of the pulleys. The control cable turnbuckles remained attached and safety wired. The control cable tension for the ailerons could not be measured due to the buckling in the right wing. Examination of the runway revealed a scrape mark with red paint consistent with the right-wing tip. ## Aircraft - Registration: [N2351U](https://openairdocs.org/deregistered/N2351U-2019-09-06), registration cancelled 2019-09-06, S/N 17249951, built 1962 (OpenAirDocs) - Reported make and model: CESSNA 172D (D) - Registry model: [Cessna 172D](https://openairdocs.org/model/cessna-172d) (registry code 2072410) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17249951 - Year built: 1962 - Airframe hours: 4024.7 - Engines: Continental O-300 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 25, 2017, 47 hours before - Departed: S50, Auburn, WA - Destination: S50, Auburn, WA - Airport: S50, Auburn Muni, runway 16, 3,400 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: none; private; airplane ratings: single-engine sea, single-engine land; medical: class 3, with waivers/limitations; last flight review June 21, 2016; seat: left; restraint: 3-point; flight hours: 911 total, 911 in this make and model, 811 as pilot in command, 11 in the last 90 days, 4 in the last 30 days, 1.5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 36 °F - Altimeter: 30.47 inHg - Observed at: KSEA, 8 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 20171207022819A](https://openairdocs.org/incident/20171207022819A), Dec 7, 2017: Cessna 172D, Auburn, WA, Substantial damage. On approach to rnwy 16, nose of aircraft veered sharply to left. The PIC corrected with right rudder. At that time the PIC also noted he had zero aileron… ## Docket (3 files) The files NTSB released with the investigation on December 15, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96477. 20.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 29 pages, 12.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11688747&FileExtension=pdf&FileName=6120r-Rel.pdf - NTSB airframe examination summary (item 2, PDF, 2 pages, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8122698&FileExtension=pdf&FileName=Airframe%20Examination-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 3, PDF, 1 page, 7.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8122085&FileExtension=pdf&FileName=72112%20Signed%20Wreckage%20RElease_Redacted-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.