# NTSB WPR20LA026: Piper PA 18, N8589D, Livermore, CA, November 16, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: November 16, 2019, 15:10 local (23:10 UTC) - Place: Livermore, CA - Coordinates: 37.696109, -121.819725 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.6961&lon=-121.8197&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Piper Aircraft Company, FAA-FSDO - NTSB case key (mKey): 100579 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20LA026 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100579/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100579 - Page: https://openairdocs.org/ntsb/WPR20LA026 ## Probable cause The improper installation of the flight control stick, which resulted in separation of the flight control stick from the stick stub assembly and an uncontrolled descent and impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system: control column section](https://openairdocs.org/ntsb-findings/01022701): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Piper PA-18, 3 cases](https://openairdocs.org/ntsb-findings/01022701/cases.md?model=7101802), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01022701/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event); cases with it: [Piper PA-18, 1 case](https://openairdocs.org/ntsb-events/338/sequence.md?model=7101802), [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md) ## Analysis During a banner tow flight, the pilot successfully picked up the banner then pulled the flight control stick back to gain altitude. The flight control stick separated from the stick hub assembly at the floor and the airplane made an uncontrolled descent to the ground. Examination of the airplane revealed that the hardware that secured the flight control stick to the stick hub assembly was connected to the flight control stick but was not attached through the mounting holes on the stick hub assembly. Given the wear marks on the stick stub assembly, it is likely that the control stick was in this position for some time and was not properly installed during prior maintenance; however, the airplane’s maintenance logbook did not specify when the control stick was last removed. ## Factual narrative On November 16, 2019, about 1510 Pacific standard time, a Piper PA-18 airplane, N8589D, sustained substantial damage when it was involved in an accident near Livermore Municipal Airport (LVK), Livermore, California. The pilot was the sole occupant on board and was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 banner tow flight. The pilot reported that he completed a preflight of the airplane, including the movement and "stability" of the flight controls, to set up a banner for pickup on the approach end of runway 07. The pilot departed runway 07 and completed one circuit in the left traffic pattern to return for the banner pickup. The tower controller then cleared the pilot for the banner pickup. The pilot approached the runway and made successful contact with the banner. As the pilot pulled the flight control stick back to gain altitude, the control stick separated from the stick stub assembly at the floor. The airplane made an uncontrolled descent and impacted the ground shortly thereafter. The airplane came to rest in a grass field about 150 ft from its first impact with the ground. Examination of the airplane by a Federal Aviation Administration inspector revealed that the hardware that secured the control stick to the stick hub assembly was secured on the control stick but was not attached through the mounting holes on the stick hub assembly. The stick hub showed signatures of rubbing and wear at the area near the bolt holes. Flight control stick and stick hub assembly The airplane’s maintenance logbooks revealed that the last inspection was performed on March 17, 2019, after which the airplane was returned to service. There were no maintenance entries that indicated the removal and installation of the control stick. ## Aircraft - Registration: [N8589D](https://openairdocs.org/aircraft/N8589D), registered now, S/N 18-6249, built 1957 (OpenAirDocs) - Reported make and model: Piper PA 18 (150) - Registry model: [Piper PA-18](https://openairdocs.org/model/piper-pa-18) (registry code 7101802) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 18-6249 - Year built: 1957 - Airframe hours: 14976 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Banner tow, Part 91 - Operator: Aerial Advertising Services - Registered owner: TeamBuilders, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 17, 2019 - Departed: LVK, Livermore, CA - Destination: LVK, Livermore, CA - Airport: LVK, Livermore Muni, runway 07R, 2,699 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review December 13, 2018; seat: front; restraint: lap only; flight hours: 1,175 total, 24 in this make and model, 1,072 as pilot in command, 27 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 59 °F, dew point 52 °F - Observed at: KLVK ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20191116011229I](https://openairdocs.org/incident/20191116011229I), Nov 16, 2019: Piper PA-18, Livermore, CA, Minor damage. Aircraft N8589D, a Piper PA-18, was being operated under a letter of authorization to perform banner tow operations. The aircraft approached the banner pick-up… ## Docket (6 files) The files NTSB released with the investigation on June 7, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100579. 12.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 7.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13974729&FileExtension=pdf&FileName=6120_Redacted-Rel%20(1)-Rel.pdf - NTSB record of conversation-faa (item 2, PDF, 1 page, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9759733&FileExtension=pdf&FileName=Record%20of%20Conversation-with%20FAA%20Inspector%20onsite_Redacted-Rel.pdf - Excerpt of maintenance logs-last annual (item 3, PDF, 1 page, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9758056&FileExtension=pdf&FileName=Excerpt%20from%20Maintenance%20Log_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation-piper aircraft inc (item 4, PDF, 1 page, 217 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13943088&FileExtension=pdf&FileName=NTSB%20Party%20Form%20-%20WPR20LA026%20-%20Piper_Redacted-Rel.pdf - Photo array-faa onsite (item 5, PDF, 6 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9755657&FileExtension=pdf&FileName=Photo%20Array-FAA%20Onsite-Rel.pdf - Photo-flight control stick attachment (item 6, PDF, 1 page, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9762650&FileExtension=pdf&FileName=Fixed%20Photo-Flight%20Control%20Stick%20and%20Hardware-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.