# NTSB GAA16CA368: Avions Mudry ET Cie CAP, N42415, Spring Branch, TX, July 5, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 5, 2016, 11:00 local (16:00 UTC) - Place: Spring Branch, TX - Coordinates: 29.811666, -98.426109 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.8117&lon=-98.4261&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 18, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - NTSB case key (mKey): 93583 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA368 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93583/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93583 - Page: https://openairdocs.org/ntsb/GAA16CA368 ## Probable cause The flight instructor's inability to maintain directional control during the landing roll as a result of the malfunctioning brake master cylinder. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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: [Avions Mudry ET Cie CAP 10B, 1 case](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=0950102), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Landing gear system: master cylinder/brake valve](https://openairdocs.org/ntsb-findings/01023243): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Avions Mudry ET Cie CAP 10B, 1 case](https://openairdocs.org/ntsb-findings/01023243/cases.md?model=0950102), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01023243/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Avions Mudry ET Cie CAP 10B, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=0950102), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Avions Mudry ET Cie CAP 10B, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=0950102), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Avions Mudry ET Cie CAP 10B, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=0950102), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Avions Mudry ET Cie CAP 10B, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=0950102), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Avions Mudry ET Cie CAP 10B, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=0950102), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis According to the flight instructor in the tailwheel-equipped airplane, during the landing roll the airplane encountered a wind gust from right, the airplane began to "weathervane" and he applied left rudder and differential braking. He reported that he was flying the airplane from the right seat and that, "Rather than attempt to keep the aircraft on the runway I allowed the aircraft to depart the right side of the runway under control and in a straight line." The flight instructor reported that he continued to apply the brakes and the airplane crossed the safety area, rolled on to the parallel taxiway, ground looped to the right and struck a drainage culvert. The airplane sustained substantial damage to the rudder. The airplane and more specifically the brake master cylinders were examined at the repair facility by a Federal Aviation Administration certificated Airframe and Powerplant Mechanic. The mechanic reported that the factory installed brake system was all original, and that the, inspection of the brake master cylinders revealed them to be un-airworthy due to aged and defective O-rings. He reported that, if air is introduced into either the left or right wheel brake master cylinders located on the left side of the airplane, then the brake pedals would be ineffective on either side of the airplane. ## Factual narrative According to the flight instructor in the tailwheel-equipped airplane, during the landing roll the airplane encountered a wind gust from right, the airplane began to "weathervane" and he applied left rudder and differential braking. He reported that he was flying the airplane from the right seat and that, "Rather than attempt to keep the aircraft on the runway I allowed the aircraft to depart the right side of the runway under control and in a straight line." The flight instructor reported that he continued to apply the brakes and the airplane crossed the safety area, rolled on to the parallel taxiway, ground looped to the right and struck a drainage culvert. The airplane sustained substantial damage to the rudder. The airplane and more specifically the brake master cylinders were examined at the repair facility by a Federal Aviation Administration certificated Airframe and Powerplant Mechanic. The mechanic reported that the factory installed brake system was all original, and that the, inspection of the brake master cylinders revealed them to be un-airworthy due to aged and defective O-rings. He reported that, if air is introduced into either the left or right wheel brake master cylinders located on the left side of the airplane, then the brake pedals would be ineffective on either side of the airplane. ## Aircraft - Registration: [N42415](https://openairdocs.org/aircraft/N42415), registered now, S/N EPC-162 (OpenAirDocs) - Reported make and model: AVIONS MUDRY ET CIE CAP (10B) - Registry model: [Avions Mudry ET Cie CAP 10B](https://openairdocs.org/model/avions-mudry-et-cie-cap-10b) (registry code 0950102) (OpenAirDocs) - Registry engine: [Lycoming AEIO-360 series](https://openairdocs.org/engine/lycoming-aeio-360-series) (registry code 41522, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: EPC-162 - Year built: 1982 - Airframe hours: 2271.9 - Engines: Lycoming AEIO-360-B2F 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Utility; Standard, Aerobatic - Last inspection: Annual, January 4, 2016, 2,271.9 hours before - Departed: 1T7, Spring Branch, TX - Destination: 1T7, Spring Branch, TX - Airport: 1T7, Kestrel Airpark, runway 12, 3,000 × 40 ft, asphalt - Equipment: Electronic flight bag or handheld device, ADS-B, Data recorder ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review March 19, 2016; seat: right; restraint: 5-point; flight hours: 9,500 total, 1,000 in this make and model, 9,500 as pilot in command, 50 in the last 90 days, 15 in the last 30 days, 0 in the last 24 hours - Pilot-rated passenger; age 55; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review April 9, 2016; seat: left; restraint: 5-point; flight hours: 6,257.7 total, 1 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 10 knots - Visibility: 10 statute miles - Temperature: 88 °F, dew point 72 °F - Altimeter: 30.01 inHg - Observed at: KSAT, 16 nm away ## 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 20160705018159I](https://openairdocs.org/incident/20160705018159I), Jul 5, 2016: Avions Mudry Et Cie CAP 10B, Spring Branch, TX, Minor damage. The pilot took the controls landing the aircraft after an instructional flight. Landing was on rwy 12 with winds from 160 at 10 knots. The right crosswind… ## Docket (3 files) The files NTSB released with the investigation on November 15, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93583. 2.4 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=40446431&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum for Record - Repair Facility A&P Statement (item 2, .PDF, 161 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446432&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20-%20Repair%20Facility%20A%26P%20Statement-Master.PDF - Photo (Courtesy of FAA) (item 3, .PDF, 1 photo, 95 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446433&FileExtension=.PDF&FileName=Photo%20(Courtesy%20of%20FAA)-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.