# NTSB WPR13LA351: Stribling RV4, N70AC, San Manuel, AZ, July 31, 2013 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 31, 2013, 12:00 local (19:00 UTC) - Place: San Manuel, AZ - Coordinates: 32.63639, -110.647224 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.6364&lon=-110.6472&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report August 7, 2014 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 87638 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR13LA351 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87638/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87638 - Page: https://openairdocs.org/ntsb/WPR13LA351 ## Probable cause The pilot’s loss of directional control during takeoff with a tailwind, which resulted in a runway excursion. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Stribling James L RV4, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=056080V), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Stribling James L RV4, 2 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=056080V), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Stribling James L RV4, 1 case](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=056080V), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Stribling James L RV4, 2 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=056080V), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Takeoff: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Stribling James L RV4, 2 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=056080V), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Takeoff: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Stribling James L RV4, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=056080V), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that, during the takeoff with a tailwind and just before reaching rotation speed, the tailwheel-equipped airplane suddenly veered left and exited the runway surface. Despite the pilot's corrective inputs, the left wing impacted terrain, and the airplane nosed over in a ravine adjacent to the runway. Postaccident examination of the airplane did not reveal any anomalies that would have precluded normal operation. ## Factual narrative On July 31, 2013, about 1200 mountain standard time, an experimental amateur built Stribling RV-4, N70AC, sustained substantial damage following a loss of control during takeoff roll, at the San Manuel Airport (E77) San Manuel, Arizona. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot, sole occupant of the airplane, sustained minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight that was originating at the time of the accident. The pilot's planned destination was Live Oak County Airport (8T6) George West, Texas. In a written statement to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that during the takeoff roll in the tailwheel equipped airplane, on runway 11 (a 4,207 feet long and 75 feet wide asphalt runway) everything seemed normal until just prior to rotation speed, when the airplane suddenly veered to the left and exited the runway surface. The pilot attempted to correct using rudder, aileron, and elevator control inputs in an effort to get the airplane airborne. Subsequently, the left wing impacted terrain as the airplane traveled down a ravine and nosed over about 420 feet from the runway. The pilot stated that he believed there was nothing wrong with the airplane or the engine. A witness located at the airport, reported, as the airplane rotated, it veered towards the left and subsequently departed the runway. Another witness, observed the pilot's preceding landing and reported that during the landing roll, the airplane continuously swerved back and forth. The swerves continued in decreasing amplitude until near the end of the 4,207 foot long runway. During a brief discussion with the pilot, the pilot stated to him that the airplane was very sensitive in ground handling. Examination of the airplane wreckage by a Federal Aviation Administration (FAA) inspector revealed that the fuselage and wings were structurally damaged. The airplane was recovered to a secure location for further examination. During a postaccident telephone interview with the NTSB IIC, the pilot stated that it was possible that he inadvertently set the stabilizer trim to an improper setting for takeoff but otherwise could not state why the accident occurred. He further stated that when he attempted control inputs to maintain control of the airplane, the airplane felt "mushy," like that experienced in practicing stalls. Postaccident examination of the airplane by the NTSB IIC revealed no anomalies with the airframe or engine that would have precluded normal operation. The stabilizer trim setting was found near the neutral position and the trim motor operated normally. The recorded wind at the time of the accident was 180 degrees off runway heading at 5 knots. ## Aircraft - Registration: [N70AC](https://openairdocs.org/deregistered/N70AC-2013-11-12), registration cancelled 2013-11-12, S/N JS01, built 2000 (OpenAirDocs) - Reported make and model: STRIBLING RV4 - Registry model: [Stribling James L RV4](https://openairdocs.org/model/stribling-james-l-rv4) (registry code 056080V) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: JS01 - Year built: 2000 - Airframe hours: 300 - Engines: LYCOMING O&VO-360 SER 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, January 6, 2013 - Departed: E77, San Manuel, AZ - Destination: 8T6, George West, TX - Airport: E77, San Manuel, runway 11, 4,207 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review December 27, 2012; seat: front; restraint: 3-point; flight hours: 300 total, 15 in this make and model, 300 as pilot in command, 25 in the last 90 days, 15 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 95 °F, dew point 48 °F - Altimeter: 30.15 inHg - Observed at: E77 ## 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 20130731015209A](https://openairdocs.org/incident/20130731015209A), Jul 31, 2013: Stribling James L RV4, San Manuel, AZ, Substantial damage. Accident summary: On July 31, 2013, an experimental home-built van?s RV-4, registration number N70AC, serial number JS-01, departed north las vegas airport… ## Other investigations on N70AC (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 WPR13CA089](https://openairdocs.org/ntsb/WPR13CA089), Jan 8, 2013: Stribling James L RV4 (N70AC), Georgetown, CA, substantial damage. Probable cause: The pilot’s improper landing flare and failure to maintain directional control during landing. ## Docket (6 files) The files NTSB released with the investigation on July 9, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87638. 2.0 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=40414120&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Witness Statement (item 2, .PDF, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414121&FileExtension=.PDF&FileName=Witness%20Statement-Redacted.PDF - AWOS Data E77 (item 3, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414122&FileExtension=.PDF&FileName=AWOS%20Data%20E77-Master.PDF - Record of Email (item 4, .PDF, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414123&FileExtension=.PDF&FileName=Record%20of%20Email-Master.PDF - NTSB Airframe Examination Report (item 5, .PDF, 92 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414124&FileExtension=.PDF&FileName=NTSB%20Airframe%20Examination%20Report-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 6, .PDF, 248 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40414125&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.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.