Aircraft Accident/Incident Report

Venice, Louisiana 70091
Wednesday, May 18, 1983 10:56 CDT

NTSB Narrative Summary Released at Completion of Accident

THE ACFT CRASHED INTO A SWAMP WITH LOW ROTOR RPM AFTER A FAILURE OF THE ACCESSORY GEARBOX POWER OUTPUT GEAR. THE PILOT RADIOED AN EMERGENCY CALL SAYING HE WAS EXPERIENCING SEVERE VIBRATIONS AND WAS LANDING. A FEW SECONDS LATER, HE RADIOED THAT HE WAS CRASHING. RESCUE ACFT FOUND THE HELICOPTER ON ITS RIGHT SIDE PARTIALLY IN WATER. THERE WAS EVIDENCE THAT THEFAILED GEAR BOX RESULTED IN LOW ROTOR SPEED WHICH WAS NOT RECOVERED DUE TO LACK OF ALTITUDE AT THE TIME OF FAILURE. AN INVESTIGATION REVEALED THAT THE POWER TURBINE OUTPUT (PTO) GEAR, PN 4-081-044-15, FAILED FROM LOW STRESS, HIGH CYCLE FATIGUE. THE FATIGUE ORIGINATED AT A POINT WERE REHARDENING BURNS CAUSED BY GRINDING WERE PRESENT. THIS GRINDING WAS ACCOMPLISHED DURING MANUFACTURING OF THE GEAR AFTER IT HAD BEEN CARBURIZED. THE PROCEDURE SHOULD HAVE BEEN ACCOMPLISHED PRIOR TO CARBURIZATION WHEN THE MATERIAL SURFACE WAS MUCH SOFTER & LESS SUSCEPTIBLE TO GRINDING BURNS.

NTSB Probable Cause Narrative

Not Yet Reported

Event Information

Type of Event Accident
Event Date 5/18/1983
Event Day of the Week Wednesday
Time of Event 1056
Event Time Zone Central Daylight Time
Event City VENICE
Event State LOUISIANA
Event Country --
Zipcode of the event site 70091
Event Date Year 1983
Event Date Month 5
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 1053 Central Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID NEW
Elevation of weather observation facility 10
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 9000
Lowest Non-Ceiling Height 2500
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 26
Dew Point at event time (in degress fahrenheit) 22
Wind Direction (degrees magnetic) 140
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 2913
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 23231
Date of most recent change to record Jan 2 2001 9:15AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N36062
NTSB Number FTW83FA238
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed Company VFR
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name AEROSPATIALE
Aircraft Model AS-350D
Aircraft Series Identifier AS-350D
Aircraft Serial Number 1237
Certified Max Gross Weight 4190
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 6
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection AAIP
Date of Last Inspection --
Airframe hours since last inspection 53
Airframe Hours 2987
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name PETROLEUM HELICOPTERS, INC.
Aircraft Owner Street Address P.O. BOX 90808
Aircraft Owner City LAFAYETTE
Aircraft Owner State LA
Aircraft Owner Country
Aircraft Owner Zipcode 70509
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Ferry
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code
Departure City WEST DELTA
Departure State GM
Departure Country
Departure Time 0
Departure Time Zone
Destination Same as Local Flt --
Destination Airport Code 7R1
Destination City VENICE
Destination State LA
Destination Country
Specific Phase of Flight Landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:36AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --