Aircraft Accident/Incident Report

Galveston, Texas 77550
Wednesday, July 13, 1994 8:38 CDT

NTSB Narrative Summary Released at Completion of Accident

THE PILOT REPORTED THAT THE HELICOPTER WAS CLIMBING THROUGH '...2,000 FEET WHEN A BUMP SIMILAR TO TURBULENCE WAS FELT. ANOTHER BUMP WAS FELT, FOLLOWED BY A MORE PRONOUNCED BUMP, THEN AIRCRAFT CONTROL WAS LOST.' HE ADDED THAT THE CYCLIC AND COLLECTIVE WERE UNRESPONSIVE. THE HELICOPTER IMPACTED THE WATER IN THE GULF OF MEXICO APRX 11 MILES OFFSHORE. ALL MAJOR COMPONENTS, EXCEPT THE VERTICAL FIN AND TAILROTOR GEARBOX, WERE RECOVERED. DURING A RECONSTRUCTION OF THE HELICOPTER, THE LEFT LATERAL SERVO ROD END WAS FOUND DISCONNECTED FROM THE SERVO EXTENSION. THE THREADS ON THE ROD END WERE INTACT AND APPEARED UNDAMAGED; HOWEVER, ONLY REMNANTS OF THE MATING INTERNAL THREADS IN THE SERVO EXTENSION REMAINED. ALMOST THE ENTIRE THREAD PROFILE WAS WORN AWAY LEAVING ONLY THE THREADED AREA THAT HAD BEEN LOCATED WITHIN THE KEYWAY SLOT OF THE ROD END. THE ZER0-TIME SERVO HAD BEEN INSTALLED 416 FLIGHT-HRS BEFORE THE ACCIDENT. THE LEFT LATERAL SERVO, WHICH IS CONNECTED BY A PUSH ROD TO THE CONTROLS AT THE MAIN ROTOR HEAD, CHANGES THE ATTITUDE OF THE HELICOPTER BY CHANGING THE ANGLE OF ATTACK OF THE MAIN ROTOR BLADES.

NTSB Probable Cause Narrative

INADEQUATE TORQUING OF THE LEFT LATERAL SERVO BY MAINTENANCE PERSONNEL, WHICH ALLOWED IT TO BECOME DISCONNECTED FROM THE CONTROLS, LEADING TO AN IN-FLIGHT LOSS OF CONTROL.

Event Information

Type of Event Accident
Event Date 7/13/1994
Event Day of the Week Wednesday
Time of Event 838
Event Time Zone Central Daylight Time
Event City GALVESTON
Event State TEXAS
Event Country --
Zipcode of the event site 77550
Event Date Year 1994
Event Date Month 7
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 850 Central Daylight Time
Direction of event from weather observation facility (degrees) 315
Weather Observation Facility ID GLS
Elevation of weather observation facility 7
Distance of event from weather observation facility (units?) 12
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 2000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 12
Air Temperature at event time (in degrees celsius) 30
Dew Point at event time (in degress fahrenheit) 25
Wind Direction (degrees magnetic) 190
Variable Wind Indicator Unknown
Wind Speed (knots) 14
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 4
Injury Total Minor --
Injury Total None --
Injury Total Serious 1
Injury Total All 5
Investigating Agency NTSB
NTSB Docket Number (internal use) 1241
NTSB Notification Source --
NTSB Notification Date Jul 13 1994 12:00AM
NTSB Notification Time 1045
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 6 2000 11:42AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N350WM
NTSB Number FTW94FA231
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
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-350B1
Aircraft Series Identifier AS-350B1
Aircraft Serial Number 2099
Certified Max Gross Weight 4850
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 100 Hour
Date of Last Inspection May 16 1994 12:00AM
Airframe hours since last inspection 96
Airframe Hours 2704
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name AMERICAN EUROCOPTER CORP.
Aircraft Owner Street Address 2701 FORUM DRIVE
Aircraft Owner City GRAND PRAIRIE
Aircraft Owner State TX
Aircraft Owner Country
Aircraft Owner Zipcode 75053
Operator is an individual? --
Operator Name SEA-LINK HELICOPTERS, INC
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 905 FAIRFAX DRIVE
Operator City GRETNA
Operator State LA
Operator Country
Operator Zip code 70056
Operator Code SYLA
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 Non-scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger/Cargo
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 830
Departure Time Zone CDT
Destination Same as Local Flt --
Destination Airport Code
Destination City OIL TANKER
Destination State GM
Destination Country
Specific Phase of Flight Climb
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
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 --