# NTSB WPR19FA146: Aviat A1, N236AM, Santa Ynez, CA, May 15, 2019 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 3 · Field · Final report - Date: May 15, 2019, 13:39 local (20:39 UTC) - Place: Santa Ynez, CA - Coordinates: 34.691112, -119.95333 - Nearby events: https://openairdocs.org/map.md?lat=34.6911&lon=-119.9533&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Lycoming, Federal Aviation Administration - NTSB case key (mKey): 99435 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR19FA146 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99435/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99435 - Page: https://openairdocs.org/ntsb/WPR19FA146 ## Probable cause The pilot’s failure to maintain clearance from mountainous terrain during cruise flight in low visibility and mountainous obscuration conditions. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ceiling/visibility/precip: obscuration](https://openairdocs.org/ntsb-findings/03035030): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; cases with it: [Aviat A-1B, 1 case](https://openairdocs.org/ntsb-findings/03035030/cases.md?model=2210406), [All aircraft, 45 cases](https://openairdocs.org/ntsb-findings/03035030/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Aviat A-1B, 4 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=2210406), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Aviat A-1B, 9 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2210406), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Effect on operation; cases with it: [Aviat A-1B, 3 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=2210406), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120) (defining event); cases with it: [Aviat A-1B, 4 cases](https://openairdocs.org/ntsb-events/120/sequence.md?model=2210406), [All aircraft, 1,074 cases](https://openairdocs.org/ntsb-events/120/sequence.md) ## Analysis Before the accident flight, the private pilot had flown to a ranch. The ranch owner reported that, after the pilot decided to return home and once, they had walked about halfway back (about 100 yards) to the airplane, the pilot sat down and told him that he was “kind of tired today.” A few minutes later, they continued walking to the airplane. Subsequently, the ranch owner watched the pilot board the airplane, taxi out, and take off. According to local law enforcement personnel, concerned friends and family notified them that the pilot had not returned. Shortly after, the Federal Aviation Administration issued an alert notice. A law enforcement air unit found the airplane wreckage the following morning on steep, rising, mountainous terrain about 8.8 miles northeast of the intended destination. Recorded radar data showed a radar target consistent with the accident airplane about 6 miles west of the ranch on a west-northwesterly heading for about 6 minutes. The airplane then turned right to a northwesterly heading and began descending. The airplane continued along this heading for about 2 minutes until the last recorded radar target, which showed the airplane was about 0.2 mile south of the accident site at 2,725 ft mean sea level. Satellite imagery around the time of the accident showed an extensive cloud layer that obscured the departure and intended destination areas. The imagery also showed that a broken layer of low stratiform-type clouds obscured the accident site and the lower terrain west of the site around the time of the accident. A TAF issued 4 minutes before the accident forecast scattered clouds at 2,500 ft above ground level at the destination airport. At the time of the accident, AIRMET Sierra was valid for mountain obscuration near the accident site. Examination of the airplane and engine revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation. Therefore, based on the evidence, it’s likely that the pilot encountered reduced visibility and mountain obscuration conditions, which likely led him to turn the airplane away from his intended destination and subsequently collide with mountainous terrain. Toxicology tests detected zolpidem, which is used for the short-term treatment of insomnia and is impairing, in the pilot’s specimens. The pilot’s wife reported that her husband was taking blood pressure medication and that he suffered from insomnia. However, despite the ranch owner’s statement that the pilot felt tired and the pilot’s history of insomnia and use of zolpidem, the available medical evidence was insufficient to determine whether he was impaired by inadequate sleep, an acute medical condition, or his use of zolpidem. ## Factual narrative The airframe, engine, and propeller logbooks were not found during the investigation. On May 15, 2019, about 1339 Pacific daylight time, an Aviat Aircraft Inc., A1-B airplane, N236AM, was destroyed when it was involved in an accident near Santa Ynez, California. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. A ranch owner reported that the pilot had landed the airplane at his ranch the morning of the accident. The ranch owner stated that, while walking with the pilot from the airplane to the club house, the wind began picking up, and the pilot decided to return home. After walking about halfway back to the airplane (about 100 yards), the pilot sat down on a bench and told the ranch owner that he was “kind of tired today.” A few minutes later, they continued walking to the airplane. The ranch owner then watched the pilot board the airplane, taxi out, and take off. The pilot was destined for Santa Ynez Airport (IZA), Santa Ynez, California, located about 23 miles east of the ranch. According to local law enforcement personnel, about 2000, concerned friends and family members notified them that the pilot had not returned, and shortly after, the Federal Aviation Administration issued an alert notice. A law enforcement air unit found the airplane wreckage the following morning on steep, rising, mountainous terrain about 8.8 miles northeast of IZA. Recorded radar data showed a radar target consistent with the accident airplane about 6 miles west of the ranch on a west-northwesterly heading at 4,675 ft mean sea level (msl). The data showed the airplane continue a west-northwesterly heading for about 6 minutes varying between 4,375 and 4,775 ft msl. Subsequently, the airplane turned right to a northwesterly heading. About 20 seconds later, the airplane started descending. The airplane continued a northwesterly heading while descending for about 2 minutes until radar contact was lost. The last recorded radar target was about 0.2 mile south of the accident site at 2,725 ft msl. Figure 1 shows the airplane’s radar track laid over an aerial view of the mountainous terrain and the departure, destination, and accident site locations. Figure 1. The airplane’s radar track laid over an aerial photograph of the mountainous terrain and the departure, destination, and accident site locations. The Santa Barbara County Sheriff-Coroner, Santa Barbara, California, performed an autopsy of the pilot. The pilot's cause of death was multiple traumatic injuries. The FAA's Forensic Sciences Laboratory performed toxicology testing of specimens from the pilot, which detected 267 (ng/mL, ng/g) zolpidem in the liver, 64 (ng/mL, ng/g) zolpidem in muscle, and atorvastatin in the liver. Zolpidem, is a prescription central nervous system depressant used for the short-term treatment of insomnia. It typically carries a warning to drivers and machinery operators that it may cause drowsiness, prolonged reactiontime, dizziness, sleepiness, blurred vision, and reduced alertness, it also may cause next-day psychomotor impairment, including impaired driving. Atorvastatin is a prescription medication used to control cholesterol and is not considered impairing. The pilot’s wife reported that the pilot was taking blood pressure medication and suffered from insomnia. The Geostationary Operational Environmental Satellite 17 visible imagery at 1331, 1336, and 1341 showed an extensive layer of clouds spanning east-to-west along the coast obscuring Santa Barbara, California and the departure ranch area, which extended immediately south of IZA, with a broken layer of low stratiform-type clouds that obscured the accident site and the lower terrain west of the site. A TAF valid from 1100 to 1400 forecast wind from 210° at 8 knots, visibility 6 miles or more, ceiling broken at 800 ft above ground level (agl), and ceiling overcast at 1,500 ft. From 1400 to 2000, the forecast was wind from 240° at 12 knots, visibility 6 miles or more, scattered clouds at 2,500 ft agl, and ceiling overcast at 8,000 ft agl. The TAF was amended at 1102 to a scattered layer of clouds at 800 ft agl and ceiling overcast at 1,500 ft agl. At the time of the accident, AIRMET Sierra was valid for mountain obscuration near the accident site. The pilot’s logbooks were not found during the investigation. Examination of the accident site revealed that the airplane had impacted mountainous terrain at an elevation of about 2,700 ft msl and an approximate magnetic heading of 284° (see figure 2 for a photograph showing an aerial view of the accident site). The main wreckage came to rest upright about 30 ft below the initial impact point and was mostly consumed by fire. All the airplane’s major structural components were present at the accident site. Figure 2. Aerial view of the accident site. The wreckage exhibited severe thermal fire damage (see figure 3 for a photograph of the wreckage). All the fabric covering was burned and/or melted away from the wing and fuselage structure, except for the outboard left horizontal stabilizer. The right wing remained attached to the airframe, but the left wing was separated from the airframe. Both the left and right wings were severely fire damaged and bent and buckled throughout their spans. Figure 3. Photograph of the recovered wreckage. The cockpit instrumentation was separated from the airframe. One gyro was separated from the instrument housing. The gimble exhibited rotational scoring. Flight control continuity was established to all primary flight control surfaces. The control cables were separated in multiple places, consistent with tension overload or being cut by wreckage recovery personnel. The forward and rear control column interconnect was intact and fire damaged. The torque tube remained attached to the elevator control surfaces and extended forward to the cockpit’s rear area. The engine was separated from the airframe; however, it remained attached tothe engine mount structure and exhibited thermal and fire damage. The crankshaft could not be rotated. Borescopic examination of the internal areas of the crankcase and cylinders revealed evidence of heavy corrosion throughout them. All connecting rods, pistons, and valves were intact. The intake and exhaust valves exhibited normal operational signatures. No evidence of preaccident mechanical failures or malfunctions were revealed with the airframe or engine that would have precluded normal operation. ## Aircraft - Registration: [N236AM](https://openairdocs.org/deregistered/N236AM-2022-07-30), registration cancelled 2022-07-30, S/N 2360, built 2006 (OpenAirDocs) - Reported make and model: Aviat A1 (B) - Registry model: [Aviat A-1B](https://openairdocs.org/model/aviat-a-1b) (registry code 2210406) (OpenAirDocs) - Registry engine: [Lycoming O-360-A1P](https://openairdocs.org/engine/lycoming-o-360-a1p) (registry code 42259, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2360 - Year built: 2006 - Engines: Lycoming O-360-A1P 180 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Departed: Montecito, CA - Destination: KIZA, Santa Ynez, CA - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; injuries: fatal; private; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; seat: left; toxicology performed; flight hours: 4,033 total ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 54 °F - Altimeter: 29.92 inHg - Observed at: KIZA, 8 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 20190515004699A](https://openairdocs.org/incident/20190515004699A), May 15, 2019: Aviat Aircraft Inc A-1B, Santa Ynez, CA, Destroyed, 1 fatal. On may 5, 2019, [privacy data omitted] piloted N236AM and impacted terrain for unknown reasons. The FAA and NTSB were unable to access site on the ground due… ## Docket (10 files) The files NTSB released with the investigation on September 29, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99435. 9.9 MB in all. - Weather study (item 1, PDF, 24 pages, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8323734&FileExtension=pdf&FileName=WPR19FA146%20-%20Santa%20Ynez,%20CA-Rel.pdf - Record of conversation - ranch owner (item 2, PDF, 1 page, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11655528&FileExtension=pdf&FileName=Record%20of%20Conversation%20witness1-Rel.pdf - Record of conversation - wife of pilot (item 3, PDF, 1 page, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11655421&FileExtension=pdf&FileName=Record%20of%20Conversation%20wife%20of%20the%20pilot-Rel.pdf - Witness statement (item 4, PDF, 1 page, 97 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11654792&FileExtension=pdf&FileName=witness_Redacted-Rel.pdf - Radar data - google earth kmz file (item 5, KMZ, 4 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11656010&FileExtension=kmz&FileName=N236AM%20-%20GE-Rel.kmz - NTSB accident site, airframe, and engine examination summary (item 6, PDF, 6 pages, 4 photos, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11655364&FileExtension=pdf&FileName=Airframe%20and%20Engine%20Examination-Rel.pdf - Autopsy memorandum for record (item 7, PDF, 1 page, 112 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11655145&FileExtension=pdf&FileName=autopsy%20Memo%20for%20Record-Rel.pdf - Statement of party representatives to NTSB investigation - Lycoming (item 8, PDF, 1 page, 760 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11655271&FileExtension=pdf&FileName=party_Redacted-Rel.pdf - Toxicological report (item 9, PDF, 1 page, 215 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11655620&FileExtension=pdf&FileName=tox%20pilot_Redacted-Rel.pdf - Photo array (item 10, PDF, 6 pages, 6 photos, 4.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11656241&FileExtension=pdf&FileName=photo%20array-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.