# NTSB ANC01LA099: Cessna 207, N9794M, Healy, AK, August 3, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 3, 2001, 12:50 local (20:50 UTC) - Place: Healy, AK - Coordinates: 63.7, -148.199996 - Nearby events: https://openairdocs.org/map.md?lat=63.7000&lon=-148.2000&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 6 uninjured - Status: Completed, report June 3, 2002 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 53213 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC01LA099 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53213/pdf - Page: https://openairdocs.org/ntsb/ANC01LA099 ## Probable cause The pilot's continued flight into adverse weather conditions after becoming lost/disoriented. Factors in the accident were rising terrain, a blind/box canyon, low clouds, and rain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, climb - became lost/disoriented, pilot in command (cause) - weather condition - clouds (contributing factor) - weather condition - rain (contributing factor) - flight into adverse weather - continued, pilot in command (cause) - In flight collision with terrain/water, climb - terrain condition - mountainous/hilly (contributing factor) - terrain condition - rising (contributing factor) - terrain condition - blind/box canyon (contributing factor) ## Analysis The certificated commerical pilot was flying the second airplane in a flight of two airplanes, within an area of mountainous terrain. Shortly after takeoff he lost sight of the first airplane, but was able to maintain radio contact. As the flight progressed, it began to rain, accompanied by diminished visibility and low ceilings. He then became disoriented to his exact position, and he mistakenly turned into a small valley. The pilot said that once he entered the valley, the terrain began rising, so he initiated a climb. The valley became too narrow to turn around, and the clouds began to close around the airplane as he continued to climb. The terrain continued to rise, and he noticed his airspeed was decreasing. Shortly thereafter, the airplane collided with rising terrain, and sustained substantial damage. ## Factual narrative On August 3, 2001, about 1250 Alaska daylight time, a wheel-equipped Cessna 207 airplane, N9794M, sustained substantial damage during an in-flight collision with terrain, about 15 miles east of Healy, Alaska. The airplane was being operated as a visual flight rules (VFR) on-demand passenger flight under Title 14, CFR Part 135, when the accident occurred. The airplane was registered to Ronald D. Rosso, and operated by Denali Air Taxi, Inc., Denali Park, Alaska. The certificated commercial pilot, and the five passengers aboard, were not injured. Instrument meteorological conditions prevailed in the area of the accident, and VFR company flight following procedures were in effect. The flight originated from the Denali Wilderness Lodge about 1240, en route to the Denali Airstrip. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on August 4, the pilot reported that his airplane was the second airplane in a flight of two airplanes transporting lodge guests to the Denali Airstrip. He stated that shortly after takeoff he lost sight of the first airplane, but maintained radio contact. He added that the standard route to the Denali Airstrip was through mountainous terrain. As the flight progressed, it began to rain, accompanied by worsening visibility and low ceilings. The pilot said that he became disoriented to his exact position, and mistakenly turned into a small valley. He said that once he entered the valley, the terrain began rising, so he initiated a climb. The valley became too narrow to turn around, and the clouds began to close around the airplane as he continued to climb. The terrain continued to rise, and he noticed his airspeed was decreasing. Shortly thereafter, the airplane collided with rising terrain, and sustained substantial damage. The emergency locator transmitter (ELT) activated, and personnel from a local helicopter operator at Denali Park, began a search, and found the airplane wreckage. The pilot stated that there were no preaccident mechanical anomalies with the airplane. ## Aircraft - Registration: [N9794M](https://openairdocs.org/aircraft/N9794M), registered now, S/N 20700730, built 1981 (OpenAirDocs) - Reported make and model: Cessna 207 - Registry model: [Cessna 207A](https://openairdocs.org/model/cessna-207a) (registry code 2073604) (OpenAirDocs) - Registry engine: [Continental IO-520-F](https://openairdocs.org/engine/continental-io-520-f) (registry code 17237, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 20700730 - Airframe hours: 6438 - Engines: Continental IO-520-F 300 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Denali Air Taxi, Inc. - Registered owner: Ronald D. Rosso - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 21, 2001, 60.6 hours before - Departed: HRR, Healy, AK - Destination: AK06, Denali Airstrip, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review April 26, 2001; seat: left; flight hours: 2,762 total, 245 in this make and model, 2,634 as pilot in command, 329 in the last 90 days, 120 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Visibility: 0.25 statute miles - Lowest ceiling: 0 ft overcast - Temperature: 55 °F ## 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 20010803039639A](https://openairdocs.org/incident/20010803039639A), Aug 3, 2001: Cessna T207A, Denali Park, AK, Substantial damage. (-23) Three aircraft departed Denali wilderness lodge on wood river east of Denali Park. One aircraft went to healy, AK, the other two were returning to the… ## Other investigations on N9794M (1) 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. - [NTSB ANC22LA007](https://openairdocs.org/ntsb/ANC22LA007), Nov 21, 2021: Cessna 207A (N9794M), Bethel, AK, substantial damage. Probable cause: The improper installation of an avionics wire harness over a fuel line, which resulted in chafing of the wire harness, arcing, and a subsequent fire. 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.