# NTSB WPR18LA094: Soko Galeb G 2, N90SR, Elko, NV, February 21, 2018 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: February 21, 2018, 10:15 local (18:15 UTC) - Place: Elko, NV - Coordinates: 40.823333, -115.788612 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.8233&lon=-115.7886&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 96779 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA094 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96779/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96779 - Page: https://openairdocs.org/ntsb/WPR18LA094 ## Probable cause An improperly installed brake cylinder, which resulted in insufficient hydraulic pressure being provided to three of the brake cylinders and the left brake being inoperable during landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: brake](https://openairdocs.org/ntsb-findings/01023242): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Soko GALEB G-2, 1 case](https://openairdocs.org/ntsb-findings/01023242/cases.md?model=0561699), [All aircraft, 297 cases](https://openairdocs.org/ntsb-findings/01023242/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Soko GALEB G-2, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=0561699), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Soko GALEB G-2, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=0561699), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Soko GALEB G-2, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=0561699), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that, upon initial landing the airplane, the left brake was inoperative, and he chose to conduct a go-around and set up for a single-brake landing. The subsequent landing was uneventful, but the left brake was still inoperative. The pilot reported that, with about 1,500 ft of runway remaining, he chose to veer the airplane off the runway to the right to avoid running off the end. Subsequently, the airplane struck a drainage ditch berm, which resulted in substantial damage to the fuselage. Examination and disassembly of the hydraulically driven left brake assembly revealed that the No. 2 brake cylinder had not been properly installed, which allowed the brake pucks to move and resulted in three of them separating from the brake assembly. The separation of the brake pucks resulted in the No. 2 cylinder's piston being moved to the full-scale inward position. Subsequently, the No. 2 cylinder's piston then fully deflected, which resulted in a hydraulic leak that subsequently led to insufficient hydraulic pressure being provided to the other brake cylinders and subsequently to the left brake being inoperative during landing. ## Factual narrative On February 21, 2018, about 1015 Pacific standard time, an experimental, amateur-built G-2 airplane N90SR, sustained substantial damage when it was involved in an accident near Elko, Nevada. The pilot sustained serious injuries. The airplane was operated as a 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, upon landing, the airplane's left brake was inoperative, and he chose to conduct a go-around and set up for a single-brake landing. The subsequent landing was uneventful; however, the left brake was still inoperative. The pilot reported that, with about 1,500 ft of runway, he chose to veer to the right off the runway surface to avoid running off the end. Subsequently, the airplane struck a drainage ditch berm. The wheel brake system was hydraulically driven, and each brake operated independently from the front or rear cockpit and from the right or left side. A hydraulic fluid reservoir was located in the front cockpit, and its quantity was indicated in a fluid quantity window. Examination of the airplane revealed that the fuselage had sustained substantial damage and that the nose and left main landing gear struts had separated from the airplane. When the right brake pedal was depressed, continuity to the right brake was established; however, when the left brake pedal was depressed, hydraulic fluid moved through the brake lines and expelled from a severed portion of the lines under the left wing. The hydraulic fluid reservoir located on the front cockpit’s left side contained a normal quantity of fluid, and the fluid quantity window indicated between the maximum and minimum level. No hydraulic fluid leaks were noted in the cockpit area or on the interior or exterior of the left wing. Hydraulic fluid was noted on the left main landing wheel area. The fluid was clear and red and appeared to be fresh. Additionally, three separated brake pucks were found in the left wheel area. Examination of the left brake assembly revealed that the separated ends of the hydraulic lines were still secured and appropriately safety wired. Two brake rotors were found loose, and the No. 2 brake cylinder worn pin indicator was recessed. The other three brake cylinders’ wear pins were found in the normal position. Disassembly of the No. 2 brake cylinder revealed that it was not properly installed, which allowed the brake pucks to move. The movement of the brake pucks resulted in three of them separating from the brake assembly. The separation of the brake pucks could result in the No. 2 cylinder's piston being moved to the full-scale, inward position. Subsequently, the full-scale deflection of the No. 2 cylinder's piston could result in a hydraulic leak and cause insufficient hydraulic pressure to be provided to the other brake cylinders, rendering the brake inoperative. According to the airport manager’s report and a review of photographs of the accident site, during the landing, the airplane exited the runway with about 1,675 ft ofrunway remaining. ## Aircraft - Registration: [N90SR](https://openairdocs.org/deregistered/N90SR-2021-01-11), registration cancelled 2021-01-11, S/N FVSG23107, built 1966 (OpenAirDocs) - Reported make and model: SOKO GALEB G 2 (A) - Registry model: [Soko GALEB G-2](https://openairdocs.org/model/soko-galeb-g-2) (registry code 0561699) (OpenAirDocs) - Registry engine: [Rolls-Royce VIPER MK522](https://openairdocs.org/engine/rolls-royce-viper-mk522) (registry code 54552, turbo-jet) (OpenAirDocs) - Category: Airplane - Serial number: FVSG23107 - Year built: 1966 - Airframe hours: 3000 - Engines: Rolls Royce Viper 2Mk22/6 2500 lbs thrust turbo jet - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, July 13, 2017 - Departed: RTS, RENO, NV - Destination: EKO, Elko, NV - Flight plan: VFR - Airport: EKO, Elko Rgnl, runway 06, 7,454 × 150 ft, asphalt - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: serious; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, waiver time limited special; last flight review June 5, 2017; seat: front; restraint: 5-point; flight hours: 21,800 total, 45 in this make and model, 14,800 as pilot in command, 65 in the last 90 days, 25 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 7,500 ft broken - Temperature: 25 °F, dew point 5 °F - Altimeter: 30.09 inHg - Observed at: EKO ## 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 20180221002939A](https://openairdocs.org/incident/20180221002939A), Feb 21, 2018: Soko GALEB G-2, Elko, NV, Substantial damage. The pilot departed reno/tahoe/stead (rts) and flew VFR to Elko Regional Airport (eko). Upon landing rollout, the pilot noticed the left brake was inoperative.… ## Docket (5 files) The files NTSB released with the investigation on March 4, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96779. 4.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 451 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=7896039&FileExtension=pdf&FileName=NTSB%20Form%206120_final_Redacted-Rel.pdf - Airport diagram (item 2, PDF, 1 page, 104 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8250275&FileExtension=pdf&FileName=Airport%20Diagram-Rel.pdf - Airframe examination report (item 3, PDF, 4 pages, 384 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8249933&FileExtension=pdf&FileName=WPR18LA094%20Airframe%20Examination-Rel.pdf - Airport event report (item 4, PDF, 6 pages, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8250016&FileExtension=pdf&FileName=Report_%20Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 5, PDF, 1 page, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8250739&FileExtension=pdf&FileName=Wreckage%20Release%201_Redacted-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.