# NTSB WPR09LA307: Gunnoe Velocity, N92VA, Livermore, CA, June 19, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 19, 2009, 16:10 local (23:10 UTC) - Place: Livermore, CA - Coordinates: 37.693332, -121.820274 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.6933&lon=-121.8203&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff-rejected takeoff: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 26, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 74114 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA307 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74114/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74114 - Page: https://openairdocs.org/ntsb/WPR09LA307 ## Probable cause The failure of the right brake due to a restricted brake rotor and subsequent brake fluid line failure as a result of inadequate maintenance. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: landing gear brakes system](https://openairdocs.org/ntsb-findings/01023240): Aircraft › Aircraft systems · Malfunction (probable cause) ## Analysis The mechanic/pilot performed engine maintenance on the experimental airplane and was taking the airplane out for a high-speed taxi and check flight. He said that during the takeoff roll the right brake did not feel as he expected it to, and he decided to abort the takeoff. As the airplane exited the runway and proceeded onto the taxiway, the pilot activated the right brake to straighten the airplane when the right brake failed. The airplane began to spin and came to rest on an adjacent grassy area where the right brake ignited a fire burning the grass and the airplane. By the time the fire department arrived, the airplane's engine section, firewall, and part of the fuselage had been fire damaged. A postaccident inspection by a Federal Aviation Administration inspector revealed that the right brake caliper had been restricted by the wheel pant. This caused drag on the brake rotor allowing it to build up heat and eventually caused the fluid line to fail. ## Factual narrative On June 19, 2009, at 1610 Pacific daylight time, an experimental Gunnoe Velocity, N92VA, experienced a brake fire in the right brake after aborting the takeoff at Livermore Municipal Airport (LVK), Livermore, California. The mechanic/pilot operated the airplane under the provisions of 14 Code of Federal Regulations Part 91, as a maintenance test flight. The airplane sustained structural damage to the fuselage and firewall. The pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed for the local area flight, and no flight plan had been filed. In the pilot's written report to the National Transportation Safety Board, he stated that following maintenance on the engine, he decided to do a runway test and possible flight test. The engine started with no problems and he commenced to taxi the airplane to the runway. A normal run up was performed, and the winds were observed to be from the west at a quartering crosswind, gusting to 20 knots. As the pilot taxied the airplane onto the runway, he stated that he compensated for the wind with the use of left brake. The pilot reported that he added power slowly, and the engine sounded normal, but not quite what he expected. As the airplane started to build up speed, it was still not quite what he expected. The pilot stated that he had to increase the pressure on the left rudder as he started the takeoff roll, and then tapped the right brake as he had over corrected to the left. The pilot stated that was when he thought that the right brake did not feel right. He raised the nose up, but it did not feel right and he decided to abort the takeoff. On the rollout the pilot reported having to hold left rudder and light brake to slow down, but gave no more thought to the right brake. As he exited the runway onto the taxiway, he activated the right brake to straighten out the airplane, and the right brake failed completely. The airplane began to spin to the left and the airplane exited onto a grassy area adjacent to the taxiway. He was not able to get the airplane back onto the taxiway due to the soft grass. The tower controller then contacted the pilot and informed him that there was a grass fire under his airplane. The pilot shut down the engine and exited the airplane, observing that the right brake had caught the grass on fire. The pilot contacted tower personnel to tell them that the airplane was on fire, and attempted to move the airplane. When he was not able to move the airplane, he pulled the fuel cutoff valve and waited for the fire department to respond. According to a Federal Aviation Administration (FAA) inspector, who examined the airplane, the right brake caliper had been restricted from floating in its normal manner due to the clearance between the wheel pant half and the caliper itself. This caused the drag on the brake rotor and eventually heat buildup. The FAA inspector reported that the heat buildup caused the right brake fluid line to fail. He also examined the leftbrake assembly and noted indications of heat buildup in the left brake assembly as well. ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff-rejected takeoff: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event) - [Takeoff-rejected takeoff: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) ## Aircraft - Registration: [N92VA](https://openairdocs.org/deregistered/N92VA-2011-04-08), registration cancelled 2011-04-08, S/N 001, built 1991 (OpenAirDocs) - Reported make and model: Gunnoe Velocity - Registry model: [Gunnoe James E JR VELOCITY](https://openairdocs.org/model/gunnoe-james-e-jr-velocity) (registry code 05618KB) (OpenAirDocs) - Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 001 - Engines: Lycoming IO-360 SER 180 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Operator: David Dent - Registered owner: Marshall Holtsclaw - Airworthiness certificate: Special, Experimental (Special) - Departed: LVK, Livermore, CA - Destination: LVK, Livermore, CA - Airport: LVK, Livermore Municipal Airport, runway 25R, 5,253 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; injuries: none; commercial, flight engineer; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review October 4, 2008; seat: left; flight hours: 4,500 total, 250 in this make and model, 17 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 48 °F - Altimeter: 29.71 inHg - Observed at: LVK ## Other investigations on N92VA (1) 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. - [NTSB DFW05CA006](https://openairdocs.org/ntsb/DFW05CA006), Oct 16, 2004: Gunnoe Velocity (N92VA), Myrick, OK, substantial damage. Probable cause: The pilot's improper wind evaluation. Contributing factors were the tailwind and the short runway. ## Docket (3 files) The files NTSB released with the investigation on March 28, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74114. 3.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345686&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photo 1 - Damage to airplane (Dent) (item 2, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345612&FileExtension=.PDF&FileName=Photo%201%20-%20Damage%20to%20airplane%20(Dent)-Master.PDF - Photo 2 - Damage to Engine (Dent) (item 3, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345613&FileExtension=.PDF&FileName=Photo%202%20-%20Damage%20to%20Engine%20(Dent)-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.