# NTSB ANC98LA032: Aerospatiale AS-350B, N158EH, Soldotna, AK, March 30, 1998 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: March 30, 1998, 11:30 local (15:30 UTC) - Place: Soldotna, AK - Coordinates: 60.319725, -150.789489 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=60.3197&lon=-150.7895&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report February 11, 2000 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 3125 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC98LA032 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3125/pdf - Page: https://openairdocs.org/ntsb/ANC98LA032 ## Probable cause The pilot's inadvertent dynamic rollover while performing a slope landing. Factors associated with the accident are the presence of rough and uneven terrain, and the pilot's improper slope landing technique. ## Analysis The pilot was practicing slope landings in preparation for an upcoming check ride. According to the pilot, he was positioning the helicopter close to the hill in order to start the maneuver. The next thing the pilot recalls, the helicopter had rolled to its left, and was upside down and on top of the hill that he was attempting to land beside. The day following the accident, the pilot reported that he now suspected that the tail rotor drive shaft became disengaged, and caused the accident. The forward tail rotor shaft assembly, and a portion of the adjoining rear tail rotor drive shaft were examined by the NTSB Materials Laboratory for inspection. The inspection discovered no evidence of an in-flight disengagement of the tail rotor drive shaft assembly prior to impact. ## Factual narrative On March 30, 1998, about 1130 Alaska standard time, a skid equipped Aerospatiale AS-350B helicopter, N158EH, crashed during landing at the Soldotna Airport, Soldotna, Alaska. The helicopter was being operated as a visual flight rules (VFR) local area flight under Title 14 CFR Part 91 when the accident occurred. The helicopter, registered to and operated by Rotor Air Alaska, Inc., Soldotna, sustained substantial damage. The solo commercial pilot received minor injuries. Visual meteorological conditions prevailed, and VFR company flight following procedures were in effect. The flight originated about 0930 at the operator's private airstrip, Soldotna. During the initial telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on March 30, 1998, at 1510, the pilot reported that he was in the process of practicing for a check ride that was scheduled for the next week. He said he selected an area just short of runway 25 to practice slope landings, and positioned the helicopter close to the hill in order to start the maneuver. The next thing he remembers, the helicopter had rolled to its left, and was upside down and on top of the hill that he was attempting to land beside. On March 31, 1998, about 1500, the pilot contacted the NTSB investigator-in-charge and reported that he now suspected that the tail rotor drive shaft became disengaged, causing the accident. In his written statement to the NTSB dated April 4, 1998, he wrote: "Upon approach to landing at 10 to 15 feet above ground level and approximately 8 to 10 knots forward speed, at a high power setting, going into hover flight, the aircraft turned violently to the left going 90 degrees nose down, and landed hard, inverted. The aircraft acted as if the tail rotor drive line failed." The forward tail rotor drive shaft assembly, and a portion of the adjoining rear tail rotor drive shaft assembly, were retained by the NTSB investigator-in-charge, and sent to the NTSB Materials Laboratory for examination. A metallurgical examination conducted by NTSB laboratory personnel discovered no evidence of an in-flight disengagement of the tail rotor drive shaft assembly prior to impact. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Roll over, landing - terrain condition - rough/uneven (contributing factor) - touchdown - improper, pilot in command (cause) - dynamic rollover - inadvertent, pilot in command (cause) ## Aircraft - Registration: [N158EH](https://openairdocs.org/deregistered/N158EH-2008-10-28), registration cancelled 2008-10-28, S/N 2055, built 1987 (OpenAirDocs) - Reported make and model: Aerospatiale AS-350B - Registry model: [Eurocopter AS 350 BA](https://openairdocs.org/model/eurocopter-as-350-ba) (registry code 8680955) (OpenAirDocs) - Registry engine: [Turbomeca ARRIEL-1SER](https://openairdocs.org/engine/turbomeca-arriel-1ser) (registry code 60030, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2055 - Airframe hours: 4436 - Engines: Turbomeca ARRIEL 1B 645 horsepower turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Rotor Air Alaska, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 13, 1997, 3 hours before - Departed: 1AK4, ROTOR AIRSTRIP, AK - Destination: SXQ - Flight plan: Company VFR - Airport: SXQ, Soldotna ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; commercial; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 16,000 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 8 knots - Visibility: 60 statute miles - Lowest ceiling: none - Temperature: 50 °F - Altimeter: 29.00 inHg ## 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 19980330008049A](https://openairdocs.org/incident/19980330008049A), Mar 30, 1998: Snias AS350B, Soldotna, AK, Substantial damage. Practice for check ride. Slope landings. Rolled left and over. Impacted inverted. (From .4) the certificated commercial helicopter pilot was practicing slope… 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.