N/A Airport
Aircraft Accident/Incident Report

Eau Claire, Wisconsin 54703
Wednesday, December 11, 2013 10:08 CST

NTSB Narrative Summary Released at Completion of Accident

The operator reported that, while in cruise flight at flight level 190, the copilot’s inner layer windshield cracked. Windshield heat was not being used at the time, and pressurization was not compromised. The pilot conducted a precautionary landing without incident. Examinations of the windshield revealed that the inner glass ply had fractured due to a peel adhesion chip at the windshield’s lower forward corner. The peel chip developed as a result of the differences in coefficient of expansion between the inboard glass ply and vinyl interlayer and had propagated due to mechanical and thermal expansion stresses until the center tension of the thermally tempered glass was penetrated, which caused a spontaneous fracture. The windshield was redesigned in 2001 to reduce the thermal expansion stresses.

NTSB Probable Cause Narrative

The failure of the copilot’s windshield inner layer due to a peel chip that developed as a result of mechanical and thermal expansion stresses.

Event Information

Type of Event Incident
Event Date 12/11/2013
Event Day of the Week Wednesday
Time of Event 1008
Event Time Zone Central Standard Time
Event City Eau Claire
Event State WISCONSIN
Event Country --
Zipcode of the event site 54703
Event Date Year 2013
Event Date Month 12
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 440000N
Event Location Longitude 0910000W
Event Location Airport N/A
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 --
Investigator's weather source Weather Observation Facility
Time of the weather observation 956 Central Standard Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID KEAU
Elevation of weather observation facility 913
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation CST
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) -23
Dew Point at event time (in degress fahrenheit) -26
Wind Direction (degrees magnetic) 280
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 7
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.44
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report KEAU 111356Z 28006KT 10SM CLR M23/M26 A3044 RMK AO
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 32953
NTSB Notification Source FAA AGL ROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Apr 7 2014 6:49PM
User who most recently changed record scoa
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N60BA
NTSB Number CEN14IA085
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed IFR
Flight plan Was Activated? Yes
Damage Minor
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BEECH
Aircraft Model E90
Aircraft Series Identifier NO SERIES
Aircraft Serial Number LW-79
Certified Max Gross Weight 10099
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats 2
Cabin Crew Seats --
Passenger Seats 6
Total number of seats on the aircraft --
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Apr 20 2013 12:00AM
Airframe hours since last inspection 158
Airframe Hours 9283
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type Unknown
Aircraft Owner Name Bemidji Aviation Services, Inc.
Aircraft Owner Street Address P.O. Box 624
Aircraft Owner City Bemidji
Aircraft Owner State MN
Aircraft Owner Country USA
Aircraft Owner Zipcode 56619-0624
Operator is an individual? No
Operator Name Bemidji Aviation Services, Inc.
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address P.O. Box 624
Operator City Bemidji
Operator State MN
Operator Country USA
Operator Zip code 56619-0624
Operator Code BEMA
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Non-scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Cargo
Type of Flying (Per_Bus / Primary) --
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code KPKD
Departure City Park Rapids
Departure State MN
Departure Country USA
Departure Time --
Departure Time Zone CST
Destination Same as Local Flt --
Destination Airport Code KPWK
Destination City Wheeling
Destination State IL
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Apr 7 2014 7:11PM
User who most recently changed record scoa
Since inspection or accident Last Inspection
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --