Aircraft Accident/Incident Report

Dousman, Wisconsin 53118
Thursday, April 30, 1992 10:45 CDT

NTSB Narrative Summary Released at Completion of Accident

THE FLIGHT INSTRUCTOR (CFI) REPORTED THE DUAL INSTRUCTIONAL FLIGHT PROCEEDED WITHOUT INCIDENT FOR THE FIRST HOUR. WHILE RETURNING TO THE AIRPORT IN CRUISE FLIGHT, A SUDDEN AND VERY VIOLENT VIBRATION OCCURRED. THE CFI TOOK THE FLIGHT CONTROLS AND BEGAN AN AUTOROTATION TO AN OFF-AIRPORT SITE, STRIKING TREES DURING THE DESCENT. INSPECTION OF THE ROTOR HEAD DISCOVERED A MISSING SWASH PLATE DRIVE LINK BOLT, WHICH ALLOWED THE DRIVE LINK TO DISCONNECT. BOTH THE CFI AND STUDENT RECALLED CHECKING THE BOLT AND ASSOCIATED NUT AND COTTER PIN PRIOR TO THE FLIGHT AND FOUND NO ANOMALIES. THE BOLT WAS NEVER LOCATED.

NTSB Probable Cause Narrative

THE IN-FLIGHT LOSS OF THE SWASH PLATE DRIVE LINK BOLT WHICH ALLOWED THE SWASH PLATE DRIVE ASSEMBLY TO DISCONNECT.

Event Information

Type of Event Accident
Event Date 4/30/1992
Event Day of the Week Thursday
Time of Event 1045
Event Time Zone Central Daylight Time
Event City DOUSMAN
Event State WISCONSIN
Event Country --
Zipcode of the event site 53118
Event Date Year 1992
Event Date Month 4
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 0
Degrees magnetic from airport 0
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1050 Central Daylight Time
Direction of event from weather observation facility (degrees) 90
Weather Observation Facility ID UES
Elevation of weather observation facility 931
Distance of event from weather observation facility (units?) 10
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 6500
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) 8
Air Temperature at event time (in degrees celsius) 13
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 50
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
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 Serious
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 1
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 2580
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 47305
Date of most recent change to record Dec 11 2000 2:50PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N52HB
NTSB Number CHI92LA137
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
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 47-G2A
Aircraft Series Identifier 47-G2A
Aircraft Serial Number 3244
Certified Max Gross Weight 2850
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 100 Hour
Date of Last Inspection Feb 7 1992 12:00AM
Airframe hours since last inspection 94
Airframe Hours 8600
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name MC DERMOTT ENTERPRISES, INC.
Aircraft Owner Street Address 200 MAIN ST.
Aircraft Owner City SULLIVAN
Aircraft Owner State WI
Aircraft Owner Country
Aircraft Owner Zipcode 53178
Operator is an individual? --
Operator Name MC DERMOTT ENTERPRISES, INC.
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 200 MAIN ST.
Operator City SULLIVAN
Operator State WI
Operator Country
Operator Zip code 53178
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) Instructional
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 930
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 --