# NTSB WPR12LA135: Cook Smith AVN Replica SU, N712AZ, St. Johns, AZ, March 13, 2012 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: March 13, 2012, 09:50 local (16:50 UTC) - Place: St. Johns, AZ - Coordinates: 34.518333, -109.378608 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.5183&lon=-109.3786&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: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report January 31, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 83130 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12LA135 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83130/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83130 - Page: https://openairdocs.org/ntsb/WPR12LA135 ## Probable cause The pilots’ failure to maintain directional control when the right brake locked up during the landing roll for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation. ## 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 · Not attained/maintained (probable cause); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=056262R), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Landing gear system: brake](https://openairdocs.org/ntsb-findings/01023242): Aircraft › Aircraft systems · Not specified (probable cause); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-findings/01023242/cases.md?model=056262R), [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. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=056262R), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=056262R), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot had recently purchased the airplane and was receiving instruction in it. The pilot reported that the day before the accident, during landing, the left brake became less responsive than the right, and the airplane veered off of the runway but incurred no damage. The pilot and his flight instructor then bled the brake lines. This was followed by taxi and touch-and-go landing checks with no anomalies noted. The following morning the brakes were tested again and were operational. During the fourth landing that morning, the right brake locked up, and the airplane swerved to the right and nosed over. Although the flight instructor indicated that he had signed off the pilot for his tailwheel endorsement the day of the accident, he did not hold a current airman medical certificate. Additionally, the instructor reported that he did not remain on the flight controls with the pilot during the landings. Postaccident examination of the brake system revealed no evidence of a mechanical malfunction or failure that would have precluded normal operation. ## Factual narrative On March 13, 2012, at 0950 mountain standard time, an experimental Cook Smith Aviation Replica SU, N712AZ, veered from the runway during landing at St. Johns Municipal Airport, St. Johns, Arizona. The private pilot sustained minor injuries and the certified flight instructor (CFI) was not injured. The airplane was substantially damaged. The pilot was operating the airplane under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed. According to the pilot, he purchased the airplane on March 12, and was ferrying it from Arizona to Texas. The CFI was providing flight instruction to the owner during the flight. While landing for fuel at St. Johns on March 12, the pilot discovered that the left brake was less responsive than the right. The airplane veered off of the runway, but incurred no damage. The pilot indicated that the brakes were not operating on either the right or left side. The pilot and CFI then decided to bleed the brake lines. The brakes were successfully tested during taxi tests, followed by touch-and-go takeoffs and landings, and the pilot and CFI remained overnight in St. Johns. The following morning, the brakes were tested again, and found to be operational. The winds were calm. The pilot and CFI departed to practice touch-and-go takeoffs and landings. During the fourth landing, the left brake was not as responsive as the right brake. The pilot reported that the right brake locked up and the airplane swerved to the right, skidding off of the runway, and the airplane came to rest inverted. The certified flight instructor (CFI) was interviewed following the accident. He reported that he was flying with the aircraft owner from Arizona to Texas. They had landed at St. Johns the previous day and encountered a problem with the brakes in the airplane. The airplane departed the runway surface but resulted in no damage. They elected to bleed the brake system and completed post maintenance checks on the airplane. No problems were noted. The following morning they completed three landings successfully. On the fourth landing, the brakes locked up and the airplane veered off into a gully. The CFI was not on the flight controls at the time, but indicated that the left brake failed. The CFI stated that the pilot had about 10 hours in a similar make and model airplane as the accident airplane. He gave the pilot his tailwheel endorsement the morning of the accident; however the CFI did not hold a current airman medical. 14 CFR Part 61.31 states, in part, "...no person may act as pilot in command of a tailwheel airplane unless that person has received and logged flight training from an authorized instructor in a tailwheel airplane and received an endorsement in the person's logbook from an authorized instructor who found the person proficient in the operation of a tailwheel airplane." The FAA accident coordinator examined the airplane following the accident. Nomechanical anomalies were identified with the braking system. ## Aircraft - Registration: [N712AZ](https://openairdocs.org/deregistered/N712AZ-2019-06-18), registration cancelled 2019-06-18, S/N 04076, built 2008 (OpenAirDocs) - Reported make and model: Cook Smith AVN Replica SU - Registry model: [Cook Ron SMITH AVN REPLICA SU](https://openairdocs.org/model/cook-ron-smith-avn-replica-su) (registry code 056262R) (OpenAirDocs) - Registry engine: [Mattituck TMX-360](https://openairdocs.org/engine/mattituck-tmx-360) (registry code 59602, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 04076 - Airframe hours: 125 - Engines: Mattituck TMX O-360 180 horsepower reciprocating - Damage: Substantial damage - Flight: Ferry, Part 91 - Operator: Clayton McMartin - Registered owner: Freedom Group, Inc. - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, March 1, 2012, 19 hours before - Departed: SJN, St. Johns, AZ - Destination: SJN, St. Johns, AZ - Airport: SJN, St. Johns Industrial Air Park, runway 14, 5,322 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review December 1, 2010; seat: front; flight hours: 257 total, 12 in this make and model, 28 in the last 90 days, 2 in the last 24 hours - Flight instructor; age 62; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; last flight review May 15, 2010; seat: rear; flight hours: 5,000 total ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 9 °F - Altimeter: 30.12 inHg - Observed at: SJN ## 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 20120313006169A](https://openairdocs.org/incident/20120313006169A), Mar 13, 2012: Cook Ron SMITH AVN REPLICA SU, St. Johns, AZ, Substantial damage. On March 13, 2012, pilot [privacy data omitted]14 at St. Johns airport during VMC conditions. During roll out the pilot lost control of the aircraft and veered… ## Other investigations on N712AZ (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 CEN17LA096](https://openairdocs.org/ntsb/CEN17LA096), Jan 31, 2017: Cook Smith Aviation Repli (N712AZ), Justin, TX, substantial damage. Probable cause: A total loss of engine power due to fuel starvation as the result of a disruption in fuel flow. ## Docket (7 files) The files NTSB released with the investigation on November 28, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83130. 2.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382198&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statement (item 2, .PDF, 36 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380094&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - FAA Record of Conversation (item 3, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380096&FileExtension=.PDF&FileName=FAA%20Record%20of%20Conversation-Master.PDF - CFI Record of Conversation (item 4, .PDF, 21 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368056&FileExtension=.PDF&FileName=CFI%20Record%20of%20Conversation-Master.PDF - Airport Manager Record of Conversation (item 5, .PDF, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380095&FileExtension=.PDF&FileName=Airport%20Manager%20Record%20of%20Conversation-Master.PDF - Tailwheel Endorsement (item 6, .PDF, 607 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368057&FileExtension=.PDF&FileName=Tailwheel%20Endorsement-Redacted.PDF - Photo 1. Accident Site (Provided by Airport Manager) (item 7, .PDF, 322 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368058&FileExtension=.PDF&FileName=Photo%201.%20Accident%20Site%20(Provided%20by%20Airport%20Manager)-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.