# NTSB LAX94IA145: Aerospatiale AS-350D, N5771L, Huelo, HI, February 28, 1994 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: February 28, 1994, 08:00 local (18:00 UTC) - Place: Huelo, HI - Coordinates: 20.869251, -156.450729 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=20.8693&lon=-156.4507&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report December 7, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28558 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94IA145 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28558/pdf - Page: https://openairdocs.org/ntsb/LAX94IA145 ## Probable cause THE OPERATOR MAINTENANCE PERSONNEL'S INADEQUATE 100-HOUR INSPECTION. THE LOOSE FUEL CONTROL LINE FITTING, THE TREE STUMP, AND THE UNSUITABLE TERRAIN WERE FACTORS IN THIS ACCIDENT. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - nonmechanical, cruise - fuel system,fuel control - failure,total - fuel system,line fitting - loose (contributing factor) - maintenance,100-hour inspection - inadequate, company maintenance personnel (cause) - Forced landing, descent - emergency - On ground/water collision with object, landing - flare/touchdown - object - tree(s) (contributing factor) - terrain condition - none suitable (contributing factor) ## Analysis THE HELICOPTER EXPERIENCED AN ENGINE DECELERATION DURING A LOCAL SIGHTSEEING FLIGHT. THE PILOT ENTERED AN AUTOROTATION AND LANDED IN A CONFINED AREA SURROUNDED BY VEGETATION. A TREE STUMP PENETRATED THE LEFT LOWER SECTION OF THE HELICOPTER. THE WRECKAGE EXAMINATION AND POSTACCIDENT ENGINE RUN-UP REVEALED THE ENGINE WOULD NOT ACCELERATE MORE THAN 58 PERCENT AND THAT THE FUEL CONTROL UNIT LINE WAS LOOSE AND WAS LEAKING FUEL. THE OPERATOR REPLACED THE FUEL CONTROL UNIT 2 DAYS BEFORE THE ACCIDENT. ## Factual narrative On February 28, 1994, about 0800 hours Hawaii standard time, an Aerospatiale AS350-D, N5771L, experienced a loss of engine power and made an emergency landing Huelo, Maui, Hawaii. The pilot was conducting a visual flight rules (VFR) sightseeing flight in the local area under Title 14 CFR Part 135. The helicopter, operated by Papillon Helicopters Inc., sustained minor damage. Neither the certificated commercial pilot nor his four passengers sustained any injuries. Visual meteorological conditions prevailed. The flight originated at the Kahului Airport, Kahului, Maui, about 0745 hours. In the accident report, the pilot said that about 12 minutes into the flight, at 8,000 feet mean sea level, the helicopter's main rotor rpm began to bleed off. The pilot was unable to maintain the altitude and elected to land in an unsuitable area at a zero airspeed touchdown. A Federal Aviation Administration (FAA) airworthiness inspector, Honolulu Flight Standards District Office, conducted the on-scene investigation. He said that the pilot stated the helicopter experienced a loss of engine power (down to 58 percent engine power) and was unable to maintain normal main rotor rpm. The pilot entered an autorotation and during the landing, a tree stump penetrated the lower left fuselage section of the helicopter. The FAA inspector examined the helicopter and could start the engine. The engine would only accelerate to 58 percent power. Further inspection revealed a fuel leak in the fuel line inlet of the fuel control unit. The operator provided the National Transportation Safety Board excerpts of the pertinent maintenance and pilot records. The maintenance records examination revealed that the company's maintenance personnel completed the required annual inspection on October 17, 1993; the helicopter had accrued 8,178.6 hours at the time of the inspection. The engine had accrued 7,770.5 hours. The operator completed a 100-hour inspection on February 23, 1994; the helicopter and engine accrued 7.4 hours since the inspection at the time of the accident. Safety Board investigators found an entry in the maintenance records that showed the fuel control unit was replaced on February 26, 1994. The maintenance records also showed that the operator's maintenance personnel performed a postreplacement engine run-up and found no leaks. The operator told Safety Board investigators that he sent the fuel control unit to the manufacturer for examination. He said that the examination revealed no evidence of any preexisting malfunctions or failures. ## Aircraft - Registration: [N5771L](https://openairdocs.org/deregistered/N5771L-2009-06-23), registration cancelled 2009-06-23, S/N 1343, built 1981 (OpenAirDocs) - Reported make and model: AEROSPATIALE AS-350D - Registry model: [S N I A S AS350D ASTAR](https://openairdocs.org/model/s-n-i-a-s-as350d-astar) (registry code 8680803) (OpenAirDocs) - Registry engine: [Lycoming LTS-101 series](https://openairdocs.org/engine/lycoming-lts-101-series) (registry code 41560, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 1343 - Airframe hours: 8556 - Engines: LYCOMING LTS101-600A3 615 horsepower turbo shaft - Damage: Minor damage - Flight: Part 135 - Operator: Papillon Helicopters Inc. - Registered owner: Papillon Helicopters Ltd. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, February 23, 1994, 7 hours before - Departed: 0GG, KAHULUI, HI - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; flight instructor, commercial; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 2,449 total, 1,375 in this make and model, 2,418 as pilot in command, 291 in the last 90 days, 103 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 20 statute miles - Lowest ceiling: none ## Other investigations on N5771L (2) 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 LAX95LA019](https://openairdocs.org/ntsb/LAX95LA019), Oct 24, 1994: Eurocopter AS-350D (N5771L), Kaupo, HI, substantial damage. Probable cause: a total loss of engine power by the corrosion fatigue failure of the compressor impeller due to the failure of company maintenance personnel to perform the prescribed daily compressor wash procedures… - [NTSB FTW82DA285](https://openairdocs.org/ntsb/FTW82DA285), Jul 19, 1982: Aerospatiale AS-350D (N5771L), Gulf Of Mexico, substantial damage 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.