Aircraft Accident/Incident Report

Cameron, Missouri 64429
Thursday, May 27, 1993 6:26 CDT

NTSB Narrative Summary Released at Completion of Accident

LIFEFLIGHT HELICOPTER WAS EN ROUTE WITH PATIENT WHEN NURSE HEARD LOUD 'POP' FOLLOWED BY 'CLATTERING' & HORN ALARM. SOON THEREAFTER, HELICOPTER IMPACTED A FIELD ON SOUTHERLY HEADING ABOUT 70' SOUTH OF TALL TREES. GROUND SCARS & DEBRIS WERE LOCATED ALONG 150' BY 80' PATH. WITNESSES SAID WIND WAS STRONG/GUSTY FROM SOUTH. HELICOPTER WAS EQUIPPED WITH TURBOMECA ARRIEL 1B ENGINE WITH TU-76 MODIFICATION. IT HAD TOTAL FLIGHT TIME OF 2482 HOURS. RECOMMENDED TIME BETWEEN OVERHAUL WAS 2500 HOURS. INVESTIGATION REVEALED ENGINE LOST POWER DUE TO FAILURE OF LABYRINTH SEAL IN 2ND STAGE TURBINE NOZZLE GUIDE VANE. TUBOMECA PERSONNEL PROPOSED THAT UNDER THERMAL LOW CYCLE FATIGUE, A CRACK COULD INITIATE ON 2ND TURBINE NOZZLE GUIDE VANE HUB, WHICH COULD LEAD TO RUB BETWEEN INNER DIAMETER OF HUB & INNER TURBINE LABYRINTH LIPS. THERE WERE 7 ENGINE FAILURES OF SIMILAR NATURE, ALL RELATED TO TU-76 STANDARD NOZZLES. TURBOMECA SERVICE BULLETIN 292 72 0153 WAS ISSUED TO IMPROVE MECHANICAL STRENGTH OF INTERNAL ENVELOPE OF 2ND STAGE NOZZLE GUIDE VANE.

NTSB Probable Cause Narrative

THE LOSS OF ENGINE POWER DUE TO FAILURE OF THE SECOND STAGE TURBINE LABYRINTH SEAL. FACTORS RELATED TO THE ACCIDENT WERE: THE UNFAVORABLE WIND AND TALL TREES BORDERING THE EMERGENCY LANDING AREA.

Event Information

Type of Event Accident
Event Date 5/27/1993
Event Day of the Week Thursday
Time of Event 626
Event Time Zone Central Daylight Time
Event City CAMERON
Event State MISSOURI
Event Country --
Zipcode of the event site 64429
Event Date Year 1993
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 Full
Investigator's weather source Witness
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Day
Lowest Ceiling Height 12000
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 15
Air Temperature at event time (in degrees celsius) 13
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 210
Variable Wind Indicator Unknown
Wind Speed (knots) 20
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 30
Altimeter Setting at event time (in. Hg) 29
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 2
Injury Total Minor --
Injury Total None --
Injury Total Serious 2
Injury Total All 4
Investigating Agency NTSB
NTSB Docket Number (internal use) 1540
NTSB Notification Source --
NTSB Notification Date May 27 1993 12:00AM
NTSB Notification Time 835
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 1:18PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N782LF
NTSB Number CHI93FA182
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-350B
Aircraft Series Identifier AS-350B
Aircraft Serial Number 1487
Certified Max Gross Weight 4630
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 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection AAIP
Date of Last Inspection May 16 1993 12:00AM
Airframe hours since last inspection 13
Airframe Hours 6064
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name ROCKY MOUNTAIN HELICOPTERS, IN
Aircraft Owner Street Address P.O. BOX 1337
Aircraft Owner City PROVO
Aircraft Owner State UT
Aircraft Owner Country
Aircraft Owner Zipcode 84603
Operator is an individual? --
Operator Name ROCKY MOUNTAIN HELICOPTERS
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address P.O. BOX 1337
Operator City PROVO
Operator State UT
Operator Country
Operator Zip code 84603
Operator Code DYRA
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 Only
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code NONE
Departure City BETHANY
Departure State MO
Departure Country
Departure Time 607
Departure Time Zone CDT
Destination Same as Local Flt --
Destination Airport Code MO21
Destination City KANSAS CITY
Destination State MO
Destination Country
Specific Phase of Flight Landing
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 Yes
Medical Flight --