# NTSB LAX01LA016: Aerospatiale AS350-BH, N532BH, Hilo, HI, October 13, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 13, 2000, 08:45 local (18:45 UTC) - Place: Hilo, HI - Coordinates: 19.689311, -155.08052 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=19.6893&lon=-155.0805&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report July 15, 2002 - Report: Approved by Office Director - NTSB case key (mKey): 50492 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX01LA016 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50492/pdf - Page: https://openairdocs.org/ntsb/LAX01LA016 ## Probable cause Inadequate maintenance by the helicopter manufacturer during manufacture, which installed skins of inadequate thickness on the tail boom. A factor in the accident was the failure of the manufacturer's quality control system to detect the inadequate thickness. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - fuselage,skin - improper - misc rotorcraft,tail boom - bent - misc rotorcraft,tail boom - buckled - maintenance - improper, manufacturer (cause) - material inadequate,improper, manufacturer - inadequate quality control, manufacturer (contributing factor) ## Analysis The tail boom of the helicopter bent downward during landing following a practice hovering autorotation. The pilot reported that the accident occurred following their third hovering autorotation landing. He said that the touchdown was acceptable and would have met check ride criteria. About 2 seconds after touchdown there was "an obvious component failure" felt throughout the airframe, accompanied by severe vibrations and "audible and physical indications" of failure. After exiting the aircraft, the pilot expected to find a problem in the main rotor head and was surprised to find the tail boom bent downward at the midpoint. A postaccident examination of the helicopter revealed that the tail boom was fabricated from skins of thickness 0.025 inches, as opposed to a skin thickness of 0.032 inches identified in the structural repair manual. The helicopter records showed that the tail boom was originally installed on the (new) helicopter at the factory and had acquired 14,053 hours in service. ## Factual narrative On October 13, 2000, at 0845 hours Hawaiian standard time, an Aerospatiale AS350-BH, N532BH, was substantially damaged when the tail boom was bent downward during landing following a practice hovering autorotation at Hilo International Airport, Hilo, Hawaii. The commercial certificated flight instructor and the airline transport certificated pilot being instructed were not injured. Visual meteorological conditions prevailed for the local area training flight, operated by Blue Hawaiian Helicopters under 14 CFR Part 91. The flight departed from Hilo at 0825, and no flight plan was filed. The pilot reported that the accident occurred following their third hovering autorotation landing. The pilot reported that the touchdown was acceptable and would have met check ride criteria. About 2 seconds after touchdown there was "an obvious component failure" felt throughout the airframe, accompanied by severe vibrations and "audible and physical indications" of failure. After exiting the aircraft, the pilot expected to find a problem in the main rotor head and was surprised to find the tail boom bent downward at the midpoint. A postaccident examination of the helicopter revealed that the tail boom was fabricated from skins of thickness 0.025 inches, as opposed to a skin thickness of 0.032 inches identified in the structural repair manual. The helicopter records showed that the tail boom was originally installed on the (new) helicopter at the factory and had acquired 14,053 hours in service. ## Aircraft - Registration: N532BH (not matched to a registry record) - Reported make and model: Aerospatiale AS350-BH - Category: Helicopter - Serial number: 2494 - Airframe hours: 14053 - Engines: Turbomeca ARRIEL 1B 641 horsepower turbo shaft - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Blue Hawaiian Helicopters - Registered owner: Helicopter Consultants Of Maui - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 18, 2000, 68 hours before - Departed: ITO, HI - Airport: ITO, Hilo International ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 16,295 total, 7,116 in this make and model, 154 in the last 90 days, 43 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 6 statute miles - Lowest ceiling: 3,200 ft broken - Temperature: 167 °F, dew point 162 °F - Altimeter: 30.00 inHg - Observed at: HTO, 1 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 20001013015089A](https://openairdocs.org/incident/20001013015089A), Oct 13, 2000: Snias AS350BA, Hilo, HI, No damage. (-23) Company pilot/cfi was instructing second company pilot. Hovering autorotations from five foot altitude were being practiced. On the third touchdown, the… 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.