# NTSB WPR21LA318: North American T-28B, N392W, Puyallup, WA, August 12, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: August 12, 2021, 14:43 local (21:43 UTC) - Place: Puyallup, WA · Airport Environment - Coordinates: 47.10392, -122.2872 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.1039&lon=-122.2872&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FSDO - NTSB case key (mKey): 103700 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA318 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103700/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103700 - Page: https://openairdocs.org/ntsb/WPR21LA318 ## Probable cause A nose wheel shimmy during the landing roll for reasons that could not be determined from the available evidence, which led to a loss of directional control. ## 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: [North American T-28B, 2 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=6402506), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Unknown/Not determined (probable cause); cases with it: [North American T-28B, 1 case](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=6402506), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Landing gear system: shimmy damper](https://openairdocs.org/ntsb-findings/01023252): Aircraft › Aircraft systems · Unknown/Not determined (probable cause); cases with it: [North American T-28B, 1 case](https://openairdocs.org/ntsb-findings/01023252/cases.md?model=6402506), [All aircraft, 3 cases](https://openairdocs.org/ntsb-findings/01023252/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [North American T-28B, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=6402506), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis The pilot reported that, after touchdown the nose wheel started to shimmy, and he was not able to steer the airplane. The airplane veered to the left side of the runway as the pilot continued to try and steer away from the edge of the runway using the right brake. When the left main landing gear wheel went off the edge of the runway, he initiated the emergency procedures to retract the landing gear, shut down the engine and open the canopy. Examination of the wreckage revealed that the nose wheel steering components and the hydraulic shimmy damper appeared to remain intact and attached to their respective mounts. The shimmy damper piston rod was actuated by hand and found to compress and extend normally. No hydraulic fluid leaks were observed on the damper. No evidence of a pre-accident mechanical failure or malfunction was revealed that would have precluded normal operation. The reason for the nose wheel shimmy could not be determined from available evidence. ## Factual narrative On August 12, 2021, about 1443 Pacific daylight time, a North American T-28B airplane, N392W, was substantially damaged when it was involved in an accident near Puyallup, Washington. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, after touchdown on runway 35 at Pierce County-Thun Field (PLU), the nose wheel started to shimmy, and he was not able to steer the airplane. The airplane veered to the left side of the runway as the pilot continued to try and steer away from the edge of the runway using the right brake. When the left main landing gear wheel went off the edge of the runway, he initiated the emergency procedures to retract the landing gear, shut down the engine and open the canopy. After the airplane came to a stop, a fire ignited the grass under the engine nacelle which was extinguished by emergency responders. The wings were substantially damaged. Examination of the wreckage revealed that the nose wheel steering components and the hydraulic shimmy damper appeared to remain intact and attached to their respective mounts. The shimmy damper piston rod was actuated by hand and found to compress and extend normally. No hydraulic fluid leaks were observed on the damper. No evidence of a pre-accident mechanical failure or malfunction was revealed that would have precluded normal operation. ## Aircraft - Registration: [N392W](https://openairdocs.org/aircraft/N392W), registered now, S/N 138314 (OpenAirDocs) - Reported make and model: NORTH AMERICAN T-28B - Registry model: [North American T-28B](https://openairdocs.org/model/north-american-t-28b) (registry code 6402506) (OpenAirDocs) - Registry engine: [Wright R-1820 series](https://openairdocs.org/engine/wright-r-1820-series) (registry code 67020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 138314 - Year built: 1955 - Airframe hours: 8683 - Engines: Curtis Wright R-1820-86 1425 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Operator: Buno 138314 LLC - Registered owner: Buno 138314 LLC - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, September 21, 2020, 49 hours before - Departed: TKE, Truckee, CA - Destination: Same as departure - Airport: PLU, Pierce County - Thun Field, runway 35, 3,651 × 60 ft, concrete - Equipment: Electronic multifunction display, Angle of attack indicator, ADS-B, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 73; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review June 19, 2020; seat: front; restraint: 4-point; flight hours: 2,700 total, 560 in this make and model, 1,500 as pilot in command, 32 in the last 90 days, 4 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Observed at: PLU ## Docket (5 files) The files NTSB released with the investigation on January 11, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103700. 18.5 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 689 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13341624&FileExtension=pdf&FileName=6120%20Pilot%20report%20Puyallup%20WA_Redacted-Rel.pdf - Airframe examination report (item 2, PDF, 3 pages, 2 photos, 505 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14820231&FileExtension=pdf&FileName=wreckage%20examination%20report-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 3, PDF, 1 page, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14339864&FileExtension=pdf&FileName=Wreckage%20Release%20N392W_Redacted-Rel.pdf - Accident video (item 4, MOV, 16.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13341359&FileExtension=mov&FileName=T28%208-12-2021%20KPLU-Rel.mov - Photo (item 5, PDF, 1 page, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14827644&FileExtension=pdf&FileName=WPR21LA318%20Photo-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.