Aircraft Accident/Incident Report

West Bend, Wisconsin 53095
Tuesady, April 24, 1990 13:50 CDT

NTSB Narrative Summary Released at Completion of Accident

THE RIGHT WING SEPARATED FROM THE AIRCRAFT DURING AN INSTRUCTIONAL AEROBATIC FLIGHT. METALLURGICAL EXAMINATION REVEALED THAT THE RIGHT WING'S LIFT STRUT-TO-WING SPAR ATTACHMENT FITTING HAD FAILED DUE TO FATIGUE PROGRESSION IN BOTH SIDE PLATES OF THE FITTING. THE INITIATION AREAS WERE IMMEDIATELY ADJACENT TO THE ENDS OF TWO WELDS. IN THE WELD HEAT AFFECTED ZONE, THE MICROSTRUCTURE TRANSITIONED FROM A SPHEROIDIZED PEARLITE REGION NEAR THE BASE METAL INTO A COARSE TEMPERED MARTENSITE REGION ADJACENT TO THE FUSION ZONE.

NTSB Probable Cause Narrative

INFLIGHT FAILURE OF THE RIGHT WING STRUT-TO-SPAR ATTACHMENT FITTING DUE TO FATIGUE INITIATED BY IMPROPER WELDING TECHNIQUES INVOLVING INADEQUATE POST-WELD COOLING CONTROL.

Event Information

Type of Event Accident
Event Date 4/24/1990
Event Day of the Week Tuesday
Time of Event 1350
Event Time Zone Central Daylight Time
Event City WEST BEND
Event State WISCONSIN
Event Country --
Zipcode of the event site 53095
Event Date Year 1990
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 1345 Central Daylight Time
Direction of event from weather observation facility (degrees) 180
Weather Observation Facility ID MWC
Elevation of weather observation facility 745
Distance of event from weather observation facility (units?) 15
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 4000
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) 7
Air Temperature at event time (in degrees celsius) 28
Dew Point at event time (in degress fahrenheit) 3
Wind Direction (degrees magnetic) 210
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
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 --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 1587
NTSB Notification Source --
NTSB Notification Date Apr 24 1990 12:00AM
NTSB Notification Time 1600
Fiche Number and/or location -used to find docket information 42857
Date of most recent change to record Dec 12 2000 4:53PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N2976R
NTSB Number CHI90FA117
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 None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BELLANCA
Aircraft Model 8KCAB
Aircraft Series Identifier 8KCAB
Aircraft Serial Number 624-80
Certified Max Gross Weight 1800
Aircraft Category Airplane
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 Feb 26 1990 12:00AM
Airframe hours since last inspection 50
Airframe Hours 1775
ELT Installed Yes
ELT Activated Unknown
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name
Aircraft Owner Street Address
Aircraft Owner City
Aircraft Owner State
Aircraft Owner Country
Aircraft Owner Zipcode
Operator is an individual? --
Operator Name GRAN-AIRE, INC.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address L.J. TIMMERMAN AIRPORT
Operator City MILWAUKEE
Operator State WI
Operator Country
Operator Zip code 53207
Operator Code AZOA
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 --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Instructional
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code MWC
Departure City MILWAUKEE
Departure State WI
Departure Country
Departure Time 1330
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 Other
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:30AM
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 --