# NTSB GAA19CA376: Piper PA 12, N4238M, Yakima, WA, June 30, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 30, 2019, 12:40 local (19:40 UTC) - Place: Yakima, WA - Coordinates: 46.566944, -120.537223 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.5669&lon=-120.5372&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 2, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 99736 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA19CA376 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99736/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99736 - Page: https://openairdocs.org/ntsb/GAA19CA376 ## Probable cause The separation of the left steering spring from the tailwheel assembly during landing for reasons that could not be determined, which resulted in a ground loop. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: steering unit](https://openairdocs.org/ntsb-findings/01023251): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Piper PA-12, 1 case](https://openairdocs.org/ntsb-findings/01023251/cases.md?model=7101202), [All aircraft, 4 cases](https://openairdocs.org/ntsb-findings/01023251/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Piper PA-12, 31 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=7101202), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Piper PA-12, 7 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=7101202), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Landing: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Piper PA-12, 17 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7101202), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Piper PA-12, 40 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7101202), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-12, 42 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101202), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event); cases with it: [Piper PA-12, 1 case](https://openairdocs.org/ntsb-events/338/sequence.md?model=7101202), [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md) ## Analysis The pilot of the tailwheel-equipped airplane reported that, during the landing roll, he felt a "tailwheel shimmy." He attempted to correct with elevator to no avail. The airplane veered right, and he attempted to add left brake, but the airplane quickly ground looped to the right. The left wing struck the runway. He then taxied the airplane to the ramp with difficulty. The pilot reported that postaccident examination revealed that the left tailwheel steering spring was missing. He added that the spring was present and operating normally during preflight and taxi before takeoff. Crash fire rescue personnel found the left steering spring on the runway while conducting an examination for runway damage. In pictures provided by the pilot, the spring appeared undamaged. The airplane sustained substantial damage to the left wing. ## Factual narrative The pilot of the tailwheel-equipped airplane reported that, during the landing roll, he felt a "tailwheel shimmy." He attempted to correct with elevator to no avail. The airplane veered to the right, he attempted to add left brake, but the airplane quickly ground looped to the right. The left wing struck the runway. He then taxied the airplane to the ramp with difficulty. Postaccident examination revealed that the left tailwheel steering spring was missing. He added that the spring was present and operating normally during preflight and taxi before takeoff. Crash fire rescue personnel found the left steering spring on the runway while conducting an examination for runaway damage. In pictures provided by the pilot, the spring appeared undamaged. The airplane sustained substantial damage to the left wing. The airport's automated weather observation station reported that, about 47 minutes before the accident, the wind was from 160° at 7 knots. The same automated station reported that, about 13 minutes after the accident, the wind was from 140° at 6 knots. The pilot landed the airplane on runway 27. ## Aircraft - Registration: [N4238M](https://openairdocs.org/aircraft/N4238M), registered now, S/N 12-3134, built 1947 (OpenAirDocs) - Reported make and model: Piper PA 12 (No Series) - Registry model: [Piper PA-12](https://openairdocs.org/model/piper-pa-12) (registry code 7101202) (OpenAirDocs) - Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 12-3134 - Year built: 1947 - Airframe hours: 2871.2 - Engines: Lycoming O-235-C1 115 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 7, 2019 - Departed: YKM, Yakima, WA - Destination: YKM, Yakima, WA - Airport: YKM, Yakima Air Terminal/Mcallister, runway 27, 7,604 × 150 ft, asphalt - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review March 17, 2019; seat: rear; restraint: lap only; flight hours: 1,297.1 total, 132.6 in this make and model, 1,210.4 as pilot in command, 79.5 in the last 90 days, 3 in the last 30 days, 3 in the last 24 hours - Pilot-rated passenger; age 67; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; seat: front; restraint: 3-point; flight hours: 750 total ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 45 °F - Altimeter: 30.04 inHg - Observed at: KYKM ## 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 20190630016649A](https://openairdocs.org/incident/20190630016649A), Jun 30, 2019: Piper PA-12, Yakima, WA, Substantial damage. The airman landed on runway 27 at kykm. On touchdown, the pilot states he experienced a noticeable tail wheel shimmy which was abnormal for that aircraft. The… ## Docket (3 files) The files NTSB released with the investigation on September 12, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99736. 4.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475505&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation - Pilot (item 2, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475506&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot-Master.PDF - Accident Photos (item 3, .PDF, 3 photos, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475507&FileExtension=.PDF&FileName=Accident%20Photos-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.