Aircraft Accident/Incident Report

Grove, Oklahoma 74344
Wednesday, May 20, 1998 9:25 CDT

NTSB Narrative Summary Released at Completion of Accident

While cruising at an altitude of 1,350 feet MSL, the pilot felt a 'sudden hesitation and [smelled the] odor of smoke.' While 'determining if [a] serious malfunction existed,' the helicopter experienced a loss of main rotor drive and altitude, 'along with a stronger burning odor.' The pilot initiated an autorotation to a field adjacent to a school. However, prior to reaching the intended landing area, the helicopter struck a pickup truck, 'flipped over, landed in [the] field and started on fire.' The pilot reported that prior to the flight he had adjusted the alignment of the main drive belt and engine.

NTSB Probable Cause Narrative

The improper alignment of the main drive belt by the owner/pilot/mechanic, which resulted in the failure of the main drive belt. A factor was the lack of suitable terrain for the forced landing.

Event Information

Type of Event Accident
Event Date 5/20/1998
Event Day of the Week Wednesday
Time of Event 925
Event Time Zone Central Daylight Time
Event City GROVE
Event State OKLAHOMA
Event Country --
Zipcode of the event site 74344
Event Date Year 1998
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 Pilot
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 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) 5
Air Temperature at event time (in degrees celsius) 24
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 180
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) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 1
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 730
NTSB Notification Source --
NTSB Notification Date May 20 1998 12:00AM
NTSB Notification Time 1010
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 11:20AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N6144S
NTSB Number FTW98LA234
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Harding
Aircraft Model REVOLUTION MINI-500B
Aircraft Series Identifier REVOLUTION
Aircraft Serial Number 0426
Certified Max Gross Weight 855
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? Yes
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 Annual
Date of Last Inspection May 20 1998 12:00AM
Airframe hours since last inspection 14
Airframe Hours 14
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ROY A. HARDING
Aircraft Owner Street Address 66250 E. 254 ROAD
Aircraft Owner City GROVE
Aircraft Owner State OK
Aircraft Owner Country
Aircraft Owner Zipcode 74344
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 None
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) Personal
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code 1H7
Departure City
Departure State
Departure Country
Departure Time 920
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 Cruise
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 --