Aircraft Accident/Incident Report

Mankato, Minnesota 56001
Monday, September 5, 1988 18:30 CDT

NTSB Narrative Summary Released at Completion of Accident

THE HOMEBUILT EXPERIMENTAL GLIDER EXPERIENCED AN INFLIGHT STRUCTURAL FAILURE OF BOTH WINGS WHICH SUBSEQUENTLY RESULTED IN A LOSS OF CONTROL AND IMPACT WITH THE TERRAIN. EXAMINATION REVEALED THE WINGS FAILED DUE TO OVERLOAD AT WING MIDSPAN NEAR THE SPOILERS. RECOVERY FROM LOOPS UTILIZING THE SPOILERS AS AIR BRAKES WILL CAUSE AN INCREASED BENDING MOMENT OUTBOARD OF THE SPOILERS AND REDUCE WING STRENGTH IN THE SPOILER BOX AREA. THE PLT HAD 35 HRS OF FLT TIME IN THE ACFT, AND HAD LOGGED PERFORMANCE OF LOOPS IN HIS PLT LOGBOOK. AEROBATICS ARE PROHIBITED IN THIS ACFT.

NTSB Probable Cause Narrative

AIRCRAFT STRUCTURAL FAILURE DUE TO OVERLOAD INDUCED BY PILOT IN THE PERFORMANCE OF UNAUTHORIZED MANEUVERS.

Event Information

Type of Event Accident
Event Date 9/5/1988
Event Day of the Week Monday
Time of Event 1830
Event Time Zone Central Daylight Time
Event City MANKATO
Event State MINNESOTA
Event Country --
Zipcode of the event site 56001
Event Date Year 1988
Event Date Month 9
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 Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1655 Central Daylight Time
Direction of event from weather observation facility (degrees) 220
Weather Observation Facility ID MKT
Elevation of weather observation facility 1020
Distance of event from weather observation facility (units?) 15
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 6000
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Thin Broken
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 15
Air Temperature at event time (in degrees celsius) 19
Dew Point at event time (in degress fahrenheit) -18
Wind Direction (degrees magnetic) 320
Variable Wind Indicator Unknown
Wind Speed (knots) 5
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 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency FAA
NTSB Docket Number (internal use) 2498
NTSB Notification Source --
NTSB Notification Date Sep 5 1988 12:00AM
NTSB Notification Time 2130
Fiche Number and/or location -used to find docket information 39781
Date of most recent change to record Dec 13 2000 12:08PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N369DK
NTSB Number CHI88DER14
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 HOMEBUILT
Aircraft Model WOODSTOCK
Aircraft Series Identifier WOODSTOCK
Aircraft Serial Number 369
Certified Max Gross Weight 450
Aircraft Category Glider
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? Yes
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 1
Number of Engines 0
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Mar 24 1988 12:00AM
Airframe hours since last inspection 35
Airframe Hours 35
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name DENNIS R. KRUSE
Aircraft Owner Street Address R. #4 BOX 147
Aircraft Owner City MANKATO
Aircraft Owner State MN
Aircraft Owner Country
Aircraft Owner Zipcode 56001
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
Departure City
Departure State
Departure Country
Departure Time 0
Departure Time Zone
Destination Same as Local Flt crash at destination city
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 Jan 2 2001 10:35AM
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 --