Aircraft Accident/Incident Report

Nunda, South Dakota 57050
Sunday, October 6, 1996 8:00 CDT

NTSB Narrative Summary Released at Completion of Accident

During the second agricultural load, a total loss of engine power occurred, and the pilot made an autorotative landing, but the helicopter was damaged during the occurrence. Examination of the engine revealed failure of six bolts that attached the accessory drive gear to the crankshaft. Further examination of the attachment bolts revealed that fatigue cracking had occurred. There was evidence that inadequate pre-load torque had been applied to the assembly. The engine had approximately 400 hours since its last overhaul.

NTSB Probable Cause Narrative

failure of maintenance personnel to properly torque the six accessory drive bolts, which resulted in fatigue failure of the undertorqued bolts.

Event Information

Type of Event Accident
Event Date 10/6/1996
Event Day of the Week Sunday
Time of Event 800
Event Time Zone Central Daylight Time
Event City NUNDA
Event State SOUTH DAKOTA
Event Country --
Zipcode of the event site 57050
Event Date Year 1996
Event Date Month 10
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 754 Central Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID BKX
Elevation of weather observation facility 1637
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
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) 9
Dew Point at event time (in degress fahrenheit) 6
Wind Direction (degrees magnetic) 340
Variable Wind Indicator Unknown
Wind Speed (knots) 7
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 1106
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1580
NTSB Notification Source --
NTSB Notification Date Oct 6 1996 12:00AM
NTSB Notification Time 1021
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 10:24AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N7925J
NTSB Number CHI97LA004
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Bell
Aircraft Model 47G-5
Aircraft Series Identifier 47G-5
Aircraft Serial Number 25041
Certified Max Gross Weight 2800
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 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Apr 15 1996 12:00AM
Airframe hours since last inspection 426
Airframe Hours 5546
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name WAYNE HURSEY AREIAL BLADES
Aircraft Owner Street Address RT 2 BOX 170
Aircraft Owner City FLANDREAU
Aircraft Owner State SD
Aircraft Owner Country
Aircraft Owner Zipcode 57028
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 Agriculture
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Aerial Application
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code SD18
Departure City FLANDREAU
Departure State SD
Departure Country
Departure Time 715
Departure Time Zone CDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Emergency 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 No
Medical Flight --