# NTSB LAX01TA278: Douglas DC-3C, N376AS, Alturas, CA, August 13, 2001 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Final report - Date: August 12, 2001, 19:05 local (Aug 13, 2001, 02:05 UTC) - Place: Alturas, CA - Coordinates: 41.430233, -120.529335 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.4302&lon=-120.5293&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 3 uninjured - Status: Completed, report May 28, 2002 - Report: Approved by Office Director - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 53039 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX01TA278 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53039/pdf - Page: https://openairdocs.org/ntsb/LAX01TA278 ## Probable cause The inadvertent encounter with terrain induced turbulence. A factor was the high terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - terrain condition - high terrain (contributing factor) - flight into adverse weather - inadvertent, pilot in command - weather condition - turbulence,terrain induced (cause) ## Analysis The operator stated that their mission was to drop smoke jumpers on the Dusenbury fire incident in the South Warner Wilderness area of the Modoc National Forest. The air was smooth as the airplane descended over the fire. The 9 smoke jumpers were let out over the fire at 8,500 feet mean sea level (msl) in five passes, followed by four more passes to drop cargo. When the jump operations were completed, 360-degree circuits were made to gain altitude for the flight back to Redding. The "fasten seatbelt" sign was turned off for jump operations and cabin securing. There were two cabin crewmembers (spotters) on board who were securing the cabin for their return flight to Redding. As the airplane crossed over a ridge line at 9,000 feet msl (800 feet above ground level), it encountered a sudden wind shear, or downdraft, but then immediately back into smooth air. One spotter hit his helmet on the ceiling, but was not injured. The second spotter, who was in mid-cabin reported, "I just broke my leg." The pilot diverted the flight to Alturas. No other turbulence was encountered prior to or after the accident event. Following the accident, the pilot filed a "Safecon Aviation Safety Communique" through the U.S. Forest Service aviation management website. Additionally, the pilot made the following recommendations to prevent future accidents of this nature: 1) Re-emphasize to flight crews the importance of cabin safety awareness. 2) Re-emphasize to flight crews the potential for hidden turbulence over mountainous terrain. 3) Emphasize the importance of remaining in stable air while cabin personnel are securing cargo and moving about the cabin at the completion of drop missions. 4) Ensure all personnel aboard the aircraft are seated with seatbelts fastened whenever turbulence is anticipated. ## Factual narrative On August 12, 2001, at 1905 hours Pacific daylight time, a Douglas DC-3C, N376AS, encountered turbulence during cruise flight over mountainous terrain following an aerial deployment of smoke jumpers near Alturas, California. The airplane was not damaged. Neither the two airline transport pilots nor the third crewmember was injured. The fourth crewmember was seriously injured. Visual meteorological conditions prevailed for the flight operated by Rhoades Aviation Inc. under a United States Forest Service contract. The public-use flight was performed under 14 CFR Part 91. The airplane departed Redding, California, at 1730, and was returning to Redding when the accident occurred. A company flight plan was filed. The operator stated that their mission was to drop smoke jumpers on the Dusenbury fire incident in the South Warner Wilderness area of the Modoc National Forest. The air was smooth as the airplane descended over the fire. The 9 smoke jumpers were let out over the fire at 8,500 feet mean sea level (msl) in five passes, followed by four more passes to drop cargo. When the jump operations were completed, 360-degree circuits were made to gain altitude for the flight back to Redding. The "fasten seatbelt" sign was turned off for jump operations and cabin securing. There were two cabin crewmembers (spotters) on board who were securing the cabin for their return flight to Redding. As the airplane crossed over a ridge line at 9,000 feet msl (800 feet above ground level), it encountered a sudden wind shear, or downdraft, but then immediately back into smooth air. One spotter hit his helmet on the ceiling, but was not injured. The second spotter, who was in mid-cabin reported, "I just broke my leg." The pilot diverted the flight to Alturas. No other turbulence was encountered prior to or after the accident event. Following the accident, the pilot filed a "Safecon Aviation Safety Communique" through the U.S. Forest Service aviation management website. Additionally, the pilot made the following recommendations to prevent future accidents of this nature: 1) Re-emphasize to flight crews the importance of cabin safety awareness. 2) Re-emphasize to flight crews the potential for hidden turbulence over mountainous terrain. 3) Emphasize the importance of remaining in stable air while cabin personnel are securing cargo and moving about the cabin at the completion of drop missions. 4) Ensure all personnel aboard the aircraft are seated with seatbelts fastened whenever turbulence is anticipated. ## Aircraft - Registration: N376AS (not matched to a registry record) - Reported make and model: Douglas DC-3C - Category: Airplane - Serial number: 27047 - Airframe hours: 18251.1 - Engines: P&W PT6-65 1230 horsepower turbo prop - Damage: No damage - Flight: Public aircraft, Part 91 - Registered owner: Rhoades Aviation, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, May 22, 2001, 110.9 hours before - Departed: RDD, Redding, CA - Flight plan: Company VFR - Airport: AAT, Alturas, CA., runway 31, 4,301 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; injuries: none; commercial, flight instructor, airline transport, flight engineer; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; last flight review June 14, 2001; seat: left; flight hours: 2,400 total, 61 in this make and model, 1,800 as pilot in command, 61 in the last 90 days, 8 in the last 30 days, 3 in the last 24 hours - Co-pilot; age 62; injuries: none; airline transport, flight instructor; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review June 8, 2001; seat: right; flight hours: 13,000 total, 62 in this make and model, 12,000 as pilot in command, 75 in the last 90 days, 25 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: none - Altimeter: 29.88 inHg - Observed at: KAAT ## 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 20010812029409A](https://openairdocs.org/incident/20010812029409A), Aug 12, 2001: Doug DC3C, Redding, CA, No damage. (.19) On August 12, 2001, at 1905 hours pacific daylight time, a Douglas DC-3C, N376AS, encountered turbulence during cruise flight over mountainous terrain… 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.