Aircraft Accident/Incident Report

Grand Forks, North Dakota 58201
Friday, July 31, 1998 18:30 CDT

NTSB Narrative Summary Released at Completion of Accident

The pilot refilled the hopper and was in the middle of a swath run when the engine rpm increased and the main rotor rpm decreased. The helicopter impacted the terrain during the forced landing and rolled over. A teardown of the transmission was performed. The inspection revealed that the clutch shoes were worn to the point that there was metal to metal contacted between the clutch shoe and the drum.

NTSB Probable Cause Narrative

The worn rotor clutch shoes, and subsequent loss of main rotor rpm.

Event Information

Type of Event Accident
Event Date 7/31/1998
Event Day of the Week Friday
Time of Event 1830
Event Time Zone Central Daylight Time
Event City GRAND FORKS
Event State NORTH DAKOTA
Event Country --
Zipcode of the event site 58201
Event Date Year 1998
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 Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1853 Central Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID GFK
Elevation of weather observation facility 844
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 7000
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) 10
Air Temperature at event time (in degrees celsius) 25
Dew Point at event time (in degress fahrenheit) 11
Wind Direction (degrees magnetic) 140
Variable Wind Indicator Unknown
Wind Speed (knots) 9
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 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) 1311
NTSB Notification Source --
NTSB Notification Date Aug 1 1998 12:00AM
NTSB Notification Time 2121
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 11:36AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1001N
NTSB Number CHI98LA292
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 M74L
Aircraft Series Identifier M74L
Aircraft Serial Number 81-037
Certified Max Gross Weight 2810
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 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Dec 20 1997 12:00AM
Airframe hours since last inspection 107
Airframe Hours 3766
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name NORTHLAND HELICOPTERS, INC.
Aircraft Owner Street Address PO BOX 82
Aircraft Owner City STACYVILLE
Aircraft Owner State IA
Aircraft Owner Country
Aircraft Owner Zipcode 50201
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 Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 0
Departure Time Zone
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 Approach
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 --