Aircraft Accident/Incident Report

San Antonio, Texas 78216
Tuesady, August 17, 1993 9:45 CDT

NTSB Narrative Summary Released at Completion of Accident

THE CREW EXPERIENCED AN UNCOMMANDED YAW TO THE RIGHT WHILE IN CRUISE FLIGHT AT FL410 WITH THE AUTO PILOT ENGAGED. A NORMAL LANDING WAS MADE WITHOUT INCIDENT AT THE INTENDED DESTINATION. EXAMINATION OF THE AIRPLANE'S RUDDER CONTROL REVEALED THAT THE SHAFT PORTION OF THE RUDDER QUADRANT WAS FRACTURED. METALLURGICAL EVALUATION OF THE FRACTURED SURFACE REVEALED THAT THE SEPARATION OF THE SHAFT PORTION WAS THE RESULT OF STRESS CORROSION CRACKING THAT INITIATED FROM OPPOSITE SIDES OF THE SHAFT AND PROGRESSED INWARD UNTIL ABOUT 60% OF THE SHAFT CROSS SECTION CRACKED DUE TO POOR CHOICE OF MATERIAL, IMPROPER RADIUS, AND EXCESSIVE TORQUE ON THE SHAFT NUT.

NTSB Probable Cause Narrative

THE FRACTURE OF THE RUDDER QUADRANT DUE TO STRESS CORROSION. A FACTOR WAS THE MANUFACTURER'S IMPROPER SELECTION OF MATERIAL.

Event Information

Type of Event Incident
Event Date 8/17/1993
Event Day of the Week Tuesday
Time of Event 945
Event Time Zone Central Daylight Time
Event City SAN ANTONIO
Event State TEXAS
Event Country --
Zipcode of the event site 78216
Event Date Year 1993
Event Date Month 8
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) 10
Air Temperature at event time (in degrees celsius) 28
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 120
Variable Wind Indicator Unknown
Wind Speed (knots) 0
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 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 8
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5043
NTSB Notification Source --
NTSB Notification Date Aug 19 1993 12:00AM
NTSB Notification Time 930
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Sep 25 2006 4:00PM
User who most recently changed record NTSB\ZUZL
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N392PT
NTSB Number FTW93IA242
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name CANADAIR
Aircraft Model CL-600-2B16
Aircraft Series Identifier CL-600-2B1
Aircraft Serial Number 5110
Certified Max Gross Weight 45100
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 13
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection May 9 1993 12:00AM
Airframe hours since last inspection 120
Airframe Hours 434
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name PET INCORPORATED
Aircraft Owner Street Address 400 SOUTH FOUTH ST.
Aircraft Owner City ST. LOUIS
Aircraft Owner State MO
Aircraft Owner Country
Aircraft Owner Zipcode 63101
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) Executive/Corporate
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code ALN
Departure City ALTON
Departure State MO
Departure Country
Departure Time 830
Departure Time Zone CDT
Destination Same as Local Flt crash at destination city
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 10:30AM
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 --