Aircraft Accident/Incident Report

Kenosha, Wisconsin 53140
Friday, July 7, 2000 18:00 CDT

NTSB Narrative Summary Released at Completion of Accident

The pilot was performing a 1/2 snap roll when the left aileron departed the airframe. The aircraft was still controllable and an uneventful landing was made. The spherical rod end bearing that was used for the center aileron hinge had broken and a subsequent metallurgical was performed. Energy dispersive spectroscopy (EDS) examination revealed "... only iron and manganese consistent with plain carbon steel. There were no appreciable amounts of chromium, nickel, or molybdenum as might be expected with an AISI 4130 or AISI 8420 material." The report also states that the "... microstructure and hardness is typical of a normalized or annealed, medium carbon steel." The metallurgical report states that the rod end fracture was due to "... reverse bending fatigue (from cycling about its lateral axis) initiating at the root of the shank threads." The aircraft designer said that the accident aircraft had a different style rod bearing installed than the original design. The designer stated that he believed that the new rod end bearing shank was made of the same material and heat treat as the original. The specification for the original rod end bearing shows that the shank is to be made from AISI 4130 or AISI 8420 steel.

NTSB Probable Cause Narrative

The fatigue failure of the rod end bearing and the separation of the aileron. A factor was the inadequate design change by the aircraft designer.

Event Information

Type of Event Accident
Event Date 7/7/2000
Event Day of the Week Friday
Time of Event 1800
Event Time Zone Central Daylight Time
Event City KENOSHA
Event State WISCONSIN
Event Country --
Zipcode of the event site 53140
Event Date Year 2000
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 Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 1752 Central Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID MKE
Elevation of weather observation facility 723
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 25000
Lowest Non-Ceiling Height 10000
Sky/Lowest/Cloud Conditions Scattered
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) 66
Dew Point at event time (in degress fahrenheit) 55
Wind Direction (degrees magnetic) 140
Variable Wind Indicator Unknown
Wind Speed (knots) 6
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) 10532
NTSB Notification Source FAA
NTSB Notification Date Jul 8 2000 12:00AM
NTSB Notification Time 2000
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Sep 26 2001 10:21AM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N112KG
NTSB Number CHI00LA189
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 Staudacher Aircraft, Inc.
Aircraft Model S-300D2
Aircraft Series Identifier S-300D2
Aircraft Serial Number 22
Certified Max Gross Weight 0
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 --
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Feb 1 2000 12:00AM
Airframe hours since last inspection 41
Airframe Hours 393
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name RICHARD MARTINEZ
Aircraft Owner Street Address 3204 TUSSELL ST
Aircraft Owner City NAPERVILLE
Aircraft Owner State IL
Aircraft Owner Country
Aircraft Owner Zipcode 60564
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 ENW
Departure City
Departure State
Departure Country
Departure Time 1800
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 Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Sep 1 2001 4:00AM
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 --