# NTSB WPR12LA074: Czech Sportplanes Sro Dynamic WT9, N247DY, Glendale, AZ, January 6, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 6, 2012, 08:00 local (15:00 UTC) - Place: Glendale, AZ - Coordinates: 33.526943, -112.29528 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.5269&lon=-112.2953&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-to runway: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 28, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 82623 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12LA074 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/82623/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=82623 - Page: https://openairdocs.org/ntsb/WPR12LA074 ## Probable cause The pilot did not shut down the engine upon recognizing a brake malfunction. Contributing to the accident was the airplane's brake malfunction for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=060007R), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Landing gear system: brake](https://openairdocs.org/ntsb-findings/01023242): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-findings/01023242/cases.md?model=060007R), [All aircraft, 297 cases](https://openairdocs.org/ntsb-findings/01023242/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=060007R), [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. - [Taxi-to runway: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=060007R), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Taxi-to runway: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=060007R), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the pilot, he performed a brake check and used the brakes numerous times while taxiing to the run-up area; however, as he approached the run-up area, the brakes failed, and the airplane continued to roll forward. He decided to steer the airplane off the taxiway surface and not risk an excursion onto the active runway. The airplane veered off the paved surface onto unprepared desert terrain, and the airplane continued to accelerate. The pilot attempted to shut down the engine with the ignition switch, but was unable to. He said that normal engine shut down is accomplished using two magneto switches on the instrument panel and not the ignition switch. The airplane then struck a boundary fence. Postaccident examination revealed that the left wheel brake assembly was damaged by impact forces consistent with the airplane’s collision with the fence. The examination of the brake system for fluid leaks and functionality did not disclose any evidence of a preexisting mechanical malfunction that would have precluded normal operation. It is likely that, if the pilot had shut down the engine before the airplane departed the taxiway surface, he would have been able to stop in time to avoid colliding with the airport boundary fence. ## Factual narrative On January 6, 2012, at 0800 mountain standard time, a Czech Sportplanes Dynamic WT-9, N247DY, collided with a fence following an excursion off the taxiway at the Glendale, Arizona, airport. The aircraft was operated by the pilot for a local area personal flight conducted under the provisions of 14 CFR Part 91 of the Federal Aviation Regulations. Visual meteorological conditions prevailed. The airplane sustained substantial damage and the pilot was not injured. While taxing to the run-up area the pilot performed a brake check and used the brakes numerous times while taxing. The pilot said that the brakes failed as he approached the run-up area and the airplane continued to roll forward. He decided to steer the airplane off the taxiway surface, and not risk an excursion onto the active runway. Once off the paved surface and onto unprepared desert terrain, the airplane continued to accelerate. The pilot attempted to shut down the engine with the ignition switch but the engine remained operating. The airplane veered to the left, continued to proceed over the unprepared terrain, and impacted the airport boundary chain link fence. The pilot said that normal engine shut down is accomplished using two magneto switches on the instrument panel and that the ignition switch does not shut down the engine. NTSB investigators examined the airplane and found the left wheel brake assembly damaged by impact forces consistent with the airplane’s collision with the chain link fence. The brake system was inspected for fluid leaks and functionality. No preexisting condition was identified that would have precluded the normal operation of the brake system. ## Aircraft - Registration: [N247DY](https://openairdocs.org/deregistered/N247DY-2013-02-20), registration cancelled 2013-02-20, S/N DY-247/2008, built 2008 (OpenAirDocs) - Reported make and model: CZECH SPORTPLANES SRO DYNAMIC WT9 - Registry model: [Czech Sportplanes Sro DYNAMIC WT9](https://openairdocs.org/model/czech-sportplanes-sro-dynamic-wt9) (registry code 060007R) (OpenAirDocs) - Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: DY-247/2008 - Airframe hours: 70 - Engines: ROTAX 912ULS 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: William B. McKee - Registered owner: Southwest Hornets Nest, LLC - Airworthiness certificate: Special, Special light-sport (Special) - Last inspection: Annual, May 18, 2011 - Departed: KGEU, Glendale, AZ - Destination: KGEU, Glendale, AZ - Airport: KGEU, Glendale Municipal Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: sport pilot; last flight review October 19, 2010; seat: left; flight hours: 3,800 total, 51 in this make and model, 3,500 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 43 °F, dew point 32 °F - Altimeter: 30.04 inHg - Observed at: KGEU ## 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 20120106000139A](https://openairdocs.org/incident/20120106000139A), Jan 6, 2012: Czech Sportplanes Sro DYNAMIC WT9, Glendale, AZ, Substantial damage. The pilot reported that he performed a brake check after start up prior to taxi, and the brakes worked normal. The pilot then began a taxi to the runup area… ## Docket (3 files) The files NTSB released with the investigation on February 2, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=82623. 4.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40362258&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photo 1 - On scene photo (item 2, .PDF, 2.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40362259&FileExtension=.PDF&FileName=Photo%201%20-%20On%20scene%20photo-Master.PDF - Aircraft Examination Notes (item 3, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40362269&FileExtension=.PDF&FileName=Aircraft%20Examination%20Notes-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.