# NTSB CEN10LA559: Beech A36TC, N468SG, Snook, TX, September 26, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 26, 2010, 17:00 local (22:00 UTC) - Place: Snook, TX - Coordinates: 30.490278, -96.469718 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.4903&lon=-96.4697&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 16, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 77399 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA559 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77399/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77399 - Page: https://openairdocs.org/ntsb/CEN10LA559 ## Probable cause The pilot's failure to recognize the change in wind velocity and his decision to make a downwind takeoff from the grass airstrip, which led to the airplane's degraded climb capability. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; cases with it: [Beech A36TC, 2 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=1151603), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; cases with it: [Beech A36TC, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=1151603), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Aircraft capability: climb capability](https://openairdocs.org/ntsb-findings/01061010): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Beech A36TC, 1 case](https://openairdocs.org/ntsb-findings/01061010/cases.md?model=1151603), [All aircraft, 183 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md) - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Beech A36TC, 3 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=1151603), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) - [Object/animal/substance: fence/fence post](https://openairdocs.org/ntsb-findings/03022047): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Beech A36TC, 1 case](https://openairdocs.org/ntsb-findings/03022047/cases.md?model=1151603), [All aircraft, 313 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Beech A36TC, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=1151603), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Beech A36TC, 2 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=1151603), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis According to the pilot, the wind had been from the north between 5 and 10 knots for most of the afternoon. He elected to make a downhill takeoff, and as the airplane neared the end of the runway it failed to gain sufficient airspeed to become airborne. The airplane continued off the runway and struck a pipe and then a fence, resulting in substantial damage to the fuselage and wing. Upon exiting the airplane, the pilot estimated that the wind had increased to 25 knots. The pilot stated there were no preimpact mechanical malfunctions or anomalies with the airplane. ## Factual narrative On September 26,2010, approximately 1700 central daylight time, a Beech A36TC, N468SG, registered to and operated by the pilot, was substantially damaged when it struck a barbed wire fence and impacted an open field during takeoff from a grass airstrip 1 mile west of Snook, Texas. Visual meteorological conditions (VMC) prevailed at the time of the accident. The personal flight was being conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The pilot, the sole occupant on board the airplane, was not injured. The cross-country flight was originating at the time of the accident, and was en route to Austin (3R9), Texas. According to the pilot's accident report, the wind had been out of the north between 5 and 10 knots for most of the afternoon. A cold front had recently passed through the area. He boarded the airplane and, unbeknownst to him, wind velocity increased to about 20 knots. The pilot elected to make a down hill takeoff. The pilot wrote, "About 3/4 way down the strip, I realized the airplane was not light on the controls and was not ready to fly. I noted the IAS was 60 knots and I kept the plane on the ground until reaching the end of the strip. I climbed up and over a barbed wire fence and crossed a deep creek. I then flew up and over a hill, but on the back side of the hill I lost lift and descended slightly. More fences and a road with ditches were coming up, so I climbed again. There was a 6-inch diameter pipe with a phone box mounted on it extending up about five feet above the fence on the near side of the road. The pipe cut off my left tip tank and the outboard portion of my left wing. After crossing the road and ditches, I struck a fence on the far side of the road and settled in a cow pasture. I went through another barbed wire fence and the rough ground in the pasture created side loads on my main gear, causing it to collapse inwards into the wells. The plane stopped and I shut the engine down normally. The nose gear remained extended and the only prop strikes were those on the fence wire." Upon exiting the airplane, the pilot estimated the wind had increased to 25 knots. The pilot said he had flown in and out of the airstrip for forty years without incident. He said the dry, freshly-mowed airstrip dropped 20 feet from the northwest to southeast. He had never installed a windsock because he was familiar with the terrain and varying wind conditions. He hadn't expected "the secondary wind gust that suddenly developed late that afternoon. A windsock is the only way I could have known about the changing wind speed." ## Aircraft - Registration: [N468SG](https://openairdocs.org/deregistered/N468SG-2011-03-16), registration cancelled 2011-03-16, S/N EA-147, built 1980 (OpenAirDocs) - Reported make and model: BEECH A36TC - Registry model: [Beech A36TC](https://openairdocs.org/model/beech-a36tc) (registry code 1151603) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: EA-147 - Airframe hours: 3764 - Engines: Continental TSIO-520-UB 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Guy E.Knolle, Jr. - Registered owner: Guy E.Knolle, Jr. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 10, 2010, 63 hours before - Departed: NONE, Snook, TX - Destination: 3R9, Austin, TX - Airport: NONE, Private Airstrip, runway 15, 2,500 × 25 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 74; injuries: none; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review December 1, 2009; seat: left; flight hours: 8,000 total, 1,000 in this make and model, 9 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 340° at 14 knots, gusting 21 - Visibility: 10 statute miles - Lowest ceiling: 5,500 ft broken - Temperature: 82 °F, dew point 70 °F - Altimeter: 29.87 inHg - Observed at: CLL, 15 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 20100926050269A](https://openairdocs.org/incident/20100926050269A), Sep 26, 2010: Beech A36TC, Snook, TX, Substantial damage. The pilot attempted a downwind, down hill takeoff from his private grass runway. The pilot was unable to gain altitude and impacted three fence lines before… ## Docket (2 files) The files NTSB released with the investigation on January 19, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77399. 192 KB in all. - NTSB Form 6120.1-2, Pilot-Operator Aircraft Accident Report (item 1, .PDF, 160 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341735&FileExtension=.PDF&FileName=NTSB%20Form%206120.1-2,%20Pilot-Operator%20Aircraft%20Accident%20Report-Redacted.PDF - Weather Reports and Records (item 2, .PDF, 32 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341738&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-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.