# NTSB ANC02LA081: MBB BO-105S, N491HL, Deadhorse, AK, July 23, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 23, 2002, 15:15 local (23:15 UTC) - Place: Deadhorse, AK - Coordinates: 69.274719, -150.538604 - Nearby events: https://openairdocs.org/map.md?lat=69.2747&lon=-150.5386&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 1, 2003 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL-FAI FSDO 01 - NTSB case key (mKey): 55285 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC02LA081 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55285/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=55285 - Page: https://openairdocs.org/ntsb/ANC02LA081 ## Probable cause The pilot's failure to correct a settling-with-power condition during a helicopter landing flare/touchdown, resulting in a hard landing and roll over. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, landing - flare/touchdown - settling with power - not corrected, pilot in command (cause) - Hard landing, landing - flare/touchdown - terrain condition - tundra - Roll over, landing - flare/touchdown ## Analysis The commercial certificated pilot departed a survey camp in a high skid-equipped helicopter, on an air taxi flight to survey potential exploration sites. The director of operations said the pilot told him that he was flying about 70 feet above the ground at 50 knots when he began a descending 180 degree left turn to land in an area of flat open tundra. The pilot indicated the airspeed decreased during the turn, and the helicopter shuddered and developed a high rate of descent. The pilot applied collective pitch and power, but the rate of descent increased. The right landing gear skid contacted the ground, and the helicopter rolled onto its right side. The pilot told the director of operations that the wind conditions were about 8 knots from the northeast. ## Factual narrative On July 23, 2002, about 1515 Alaska daylight time, a high skid-equipped Messerschmitt Bolkow Blohm (MBB) BO-105S helicopter, N491HL, sustained substantial damage when it collided with tundra-covered ground after developing a high rate of descent during the landing flare in a remote area, about 70 miles south-southwest of Deadhorse, Alaska. The helicopter was being operated as a visual flight rules (VFR) domestic on-demand passenger flight under Title 14, CFR Part 135, when the accident occurred. The helicopter was operated by Air Logistics of Alaska Inc., Fairbanks, Alaska. The commercial certificated pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. A VFR flight plan was filed. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on July 24, the director of operations for the operator reported the pilot departed a survey camp area known as Happy Valley, located about 20 miles south of Deadhorse along the Sagavanirktok River, on a flight to survey potential exploration sites. The director of operations said the pilot told him that he was flying about 70 feet above the ground at 50 knots. The pilot then began a descending 180 degree left turn to land in an area of flat open tundra. During the turn, the pilot began decreasing the airspeed. The helicopter shuddered and developed a high rate of descent. The pilot applied collective pitch and power, but the rate of descent increased. The right landing gear skid contacted the ground, and the helicopter rolled onto its right side. The pilot told the director of operations that the wind conditions were about 8 knots from the northeast. ## Aircraft - Registration: [N491HL](https://openairdocs.org/deregistered/N491HL-2003-03-12), registration cancelled 2003-03-12, S/N S-664, built 1984 (OpenAirDocs) - Reported make and model: MBB BO-105S - Registry model: [Messerschmitt-Boelkow-Blohm BO-105S CDN-BS-4](https://openairdocs.org/model/messerschmitt-boelkow-blohm-bo-105s-cdn-bs-4) (registry code 5627000) (OpenAirDocs) - Registry engine: [Allison 250 series](https://openairdocs.org/engine/allison-250-series) (registry code 03014, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: S-664 - Airframe hours: 10120 - Engines: Allison 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Registered owner: Air Logistics Of Alaska Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, July 15, 2002, 13 hours before - Departed: DEADHORSE, AK - Destination: DEADHORSE, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: none; commercial; instrument ratings: helicopter; medical: class 1, valid medical--w/ waivers/lim; last flight review May 15, 2002; seat: right; flight hours: 6,151 total, 105 in this make and model, 5,291 as pilot in command, 120 in the last 90 days, 90 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: 600 ft overcast - Temperature: 37 °F - Altimeter: 29.95 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 20020723016189A](https://openairdocs.org/incident/20020723016189A), Jul 23, 2002: Bolkms BO105S, Deadhorse, AK, No damage. (.19) On July 23, 2002, about 1515 Alaska daylight time, a high skid-equipped mbb BO-105 helicopter, N491HL, sustained substantial damage during landing in a… ## Docket (1 files) The files NTSB released with the investigation on December 9, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=55285. 530 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 530 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40463625&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.