# NTSB WPR12CA209: Piper PA-28-140, N2839T, Sula, MT, June 8, 2012 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: June 8, 2012, 17:00 local (23:00 UTC) - Place: Sula, MT - Coordinates: 45.716945, -113.920555 - Nearby events: https://openairdocs.org/map.md?lat=45.7169&lon=-113.9206&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report October 4, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 83659 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12CA209 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83659/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83659 - Page: https://openairdocs.org/ntsb/WPR12CA209 ## Probable cause The pilot's inability to maintain clearance from terrain while operating in a downdraft over mountainous terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Piper PA-28-140, 15 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=7102802), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Piper PA-28-140, 3 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=7102802), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Not specified; cases with it: [Piper PA-28-140, 5 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=7102802), [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: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) (defining event); cases with it: [Piper PA-28-140, 3 cases](https://openairdocs.org/ntsb-events/390/sequence.md?model=7102802), [All aircraft, 224 cases](https://openairdocs.org/ntsb-events/390/sequence.md) - [Enroute-cruise: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-28-140, 137 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7102802), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that the airplane was in cruise flight between 2,000 and 2,500 feet above ground level over mountainous terrain when it encountered a strong downdraft. At full power and at the airplane’s best rate of climb, it was descending 1,500 feet per minute. The pilot stated that he could not turn left because of a mountain and that he was afraid that turning right would result in a greater loss of altitude and a collision with trees. When he was sure that he was not going to clear the terrain, he performed a steep left turn. The airplane subsequently collided with an embankment next to a road with the engine at full power and the stall warning light on. ## Factual narrative The pilot reported that the airplane was in cruise flight at 2,000 - 2,500 feet above ground level over mountainous terrain when it encountered a strong downdraft. At full power and best rate of climb, the airplane was descending 1,500 feet per minute. The pilot stated that he could not turn left because of a mountain, and he was afraid that turning right would result in a greater loss of altitude and a collision with trees. When he was sure that he was not going to clear the terrain, he performed a steep left turn. The airplane subsequently collided with an embankment next to a road with the engine at full power and the stall warning light on. ## Aircraft - Registration: [N2839T](https://openairdocs.org/deregistered/N2839T-2012-08-23), registration cancelled 2012-08-23, S/N 28-7225248, built 1972 (OpenAirDocs) - Reported make and model: PIPER PA-28-140 - Registry model: [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140) (registry code 7102802) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-7225248 - Airframe hours: 5810 - Engines: LYCOMING O-320 SERIES 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Raymond E CHATTERTON - Registered owner: Raymond E CHATTERTON - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 1, 2011 - Departed: 6S5, Hamilton, MT - Destination: IDA, Idaho Falls, ID ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: minor; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review December 18, 2010; seat: left; flight hours: 1,661 total, 35 in this make and model, 35 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 10 knots, gusting 20 - Visibility: 10 statute miles - Lowest ceiling: 7,000 ft overcast - Temperature: 59 °F, dew point 34 °F - Altimeter: 29.78 inHg - Observed at: KBTM, 60 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 20120608009569A](https://openairdocs.org/incident/20120608009569A), Jun 8, 2012: Piper PA-28-140, Substantial damage. At 1600 MST the PA-28 struck a road bank while turning away from turbulance. Aircraft impacted an embankment alongside highway 93 in a level attitude with all… ## Docket (3 files) The files NTSB released with the investigation on July 25, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83659. 1.8 MB in all. - Pilot Logbook Excerpts (item 1, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40372024&FileExtension=.PDF&FileName=Pilot%20Logbook%20Excerpts-Redacted.PDF - Pilot Statement (item 2, .PDF, 126 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40372026&FileExtension=.PDF&FileName=Pilot%20Statement-Redacted.PDF - Sheriff Report (item 3, .PDF, 257 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40373012&FileExtension=.PDF&FileName=Sheriff%20Report-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.