# NTSB WPR11LA458: Aviat Pitts S-2B, N46BT, Redlands, CA, September 19, 2011 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: September 19, 2011, 08:50 local (15:50 UTC) - Place: Redlands, CA - Coordinates: 34.084999, -117.14611 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.0850&lon=-117.1461&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-aerobatics: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report January 31, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 81836 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA458 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81836/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81836 - Page: https://openairdocs.org/ntsb/WPR11LA458 ## Probable cause The pilot’s failure to maintain airspeed while maneuvering, which resulted in an aerodynamic stall. Contributing to the accident was the pilot’s impairment from alcohol. ## 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: [Aviat PITTS S-2B, 2 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2210308), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Aviat PITTS S-2B, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=2210308), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Impairment/incapacitation: alcohol](https://openairdocs.org/ntsb-findings/02012015): Personnel issues › Physical · Pilot (probable cause); cases with it: [Aviat PITTS S-2B, 1 case](https://openairdocs.org/ntsb-findings/02012015/cases.md?model=2210308), [All aircraft, 87 cases](https://openairdocs.org/ntsb-findings/02012015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-aerobatics: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Aviat PITTS S-2B, 2 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2210308), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering-aerobatics: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Aviat PITTS S-2B, 2 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2210308), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that the airplane stalled while maneuvering at a low altitude. He attempted to recover from the stall; however, the airplane continued to descend and subsequently collided with terrain. First responders to the accident site reported that they noted an odor of alcohol when they spoke to the pilot at the accident site. About one hour after the accident, a blood sample from the pilot was secured and later tested for alcohol intoxicants. The test results showed that the pilot’s blood alcohol concentration (BAC) was .04 percent. According to the Federal Aviation Administration, effects of a BAC of .04 percent can include decreased attention, impaired judgment, and increased reaction time. The pilot later reported that he had consumed alcohol prior to the accident flight. The pilot also reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operations. ## Factual narrative On September 19, 2011, about 0850 Pacific daylight time (PDT), a Pitts S-2B airplane, N46BT, collided with the ground near Redlands, California. The private pilot, the sole occupant, sustained serious injuries. The airplane was consumed by fire and sustained substantial damage. The airplane was registered to the pilot, and operated under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions prevailed and no flight plan had been filed. The flight originated from the Redlands Municipal Airport, Redlands, California, about 0830. Witnesses reported that the pilot was conducting aerobatic maneuvers over the airport when the airplane impacted terrain adjacent to an airport perimeter fence. After impact, the airplane slid into an unoccupied vehicle that was parked on the shoulder of a city roadway. A post crash fire ensued. The pilot reported that he was maneuvering in the local area shortly after takeoff and that during a turn, the airplane stalled approximately 350 feet above the ground. He reported that the airspeed in the turn was slow, between 70-80 knots. The pilot attempted to recover from the stall; however, the airplane continued to descend and subsequently collided with terrain. First responders to the accident site reported that they noted an odor of alcoholic beverage when they made contact with the pilot at the accident site. About one hour after the accident a blood sample from the pilot was secured, and later tested for alcohol intoxicants. The test results showed that the pilot’s blood alcohol content (BAC)was .04 percent. During a telephone conversation after the accident with the NTSB investigator-in-charge, the pilot stated that he had consumed alcohol prior to the accident flight. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operations. According to the Federal Aviation Administration, effects of a BAC of .04% can include decreased attention, impaired judgment, and increased reaction time. It advises that "The number of serious errors committed by pilots dramatically increases at or above concentrations of 0.04% blood alcohol. This is not to say that problems don’t occur below this value. Some studies have shown decrements in pilot performance with blood alcohol concentrations as low as 0.025%." Title 14 CFR Part 91.17, Alcohol or Drugs, states, "(a) No person may act as a crewmember of a civil aircraft (1) Within 8 hours after the consumption of any alcoholic beverage; (2) While under the influence of alcohol…(4) While having an alcohol concentration of 0.04 or greater in a blood…" ## Aircraft - Registration: [N46BT](https://openairdocs.org/deregistered/N46BT-2013-04-17), registration cancelled 2013-04-17, S/N 5245, built 1992 (OpenAirDocs) - Reported make and model: AVIAT INC PITTS S-2B - Registry model: [Aviat PITTS S-2B](https://openairdocs.org/model/aviat-pitts-s-2b) (registry code 2210308) (OpenAirDocs) - Registry engine: [Lycoming AEIO-540 series](https://openairdocs.org/engine/lycoming-aeio-540-series) (registry code 41568, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 5245 - Engines: LYCOMING AEIO-540 SER 260 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Operator: Sowell Paul A - Registered owner: Sowell Paul A - Airworthiness certificate: Standard, Aerobatic; Standard, Normal - Departed: REI, Redlands, CA - Destination: REI, Redlands, CA - Airport: REI, Redlands Municipal Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: serious; private; airplane ratings: single-engine land, multi-engine land; medical: class 3, without waivers/limitations; toxicology performed; flight hours: 2,500 total, 400 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 52 °F - Altimeter: 29.98 inHg - Observed at: SBD, 4 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). - [Accident 20110919023229A](https://openairdocs.org/incident/20110919023229A), Sep 19, 2011: Aviat Inc PITTS S-2B, Redlands, CA, Destroyed. Aviat pitts crashed on sessums drive, south of Redlands airport, under unknown circumstances. Aircraft clipped a parked/unoccupied vehicle. Single occupant… ## Docket (2 files) The files NTSB released with the investigation on November 30, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81836. 184 KB in all. - Pilot - Record of Conversation (item 1, .PDF, 105 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380187&FileExtension=.PDF&FileName=Pilot%20-%20Record%20of%20Conversation-Master.PDF - Toxicological Report- Police (item 2, .PDF, 79 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40380199&FileExtension=.PDF&FileName=Toxicological%20Report-%20Police-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.