Municipal Airport
Aircraft Accident/Incident Report

Mineral Wells, Texas 76067
Sunday, June 10, 1990 8:15 CDT

NTSB Narrative Summary Released at Completion of Accident

THE AIRPLANE HAD BEEN MODIFIED TO BE FLOWN EITHER REMOTELY OR BY THE PILOT. TAKEOFF AND INITIAL CLIMB WERE PERFORMED BY REMOTE CONTROL AND CONTROL WAS TRANSFERRED TO THE PILOT TO POSITION FOR A REMOTE CONTROL LANDING. ANGLE OF BANK INCREASED PAST 90 DEGREES IN A NOSE HIGH ATTITUDE AT ABOUT 425 FEET AGL; THE PILOT TRANSMITTED THAT HE WAS 'GOING DOWN' SHORTLY BEFORE IMPACT. ONE OF THE THREE WOODEN PROPELLER BLADES SEPARATED FROM THE HUB AND WAS FOUND 1/4 MILE FROM THE MAIN WRECKAGE. THE BLADE WAS ATTACHED TO THE HUB PRIMARILY BY 5 LAG SCREWS. THREADS IN THE WOOD BUTT OF THE SEPARATED BLADE WERE STRIPPED. THE 5 SCREWS REMAINED IN PLACE. LAG SCREWS IN THE REMAINING 2 BLADES WERE FOUND UNDERTORQUED. SEVERAL DISCREPANCIES WERE NOTED REGARDING SPECIFICATIONS FOR PROPELLER BLADE ROOT AND SIZE, TOLERANCES, AND LAG SCREWS.

NTSB Probable Cause Narrative

TOTAL PROPELLER BLADE RETENTION FAILURE, THE RESULTANT SEPARATION OF ONE PROPELLER BLADE, AND THE IMPROPER INSTALLATION OF THE PROPELLER BY UNKNOWN MAINTENANCE PERSONNEL.

Event Information

Type of Event Accident
Event Date 6/10/1990
Event Day of the Week Sunday
Time of Event 815
Event Time Zone Central Daylight Time
Event City MINERAL WELLS
Event State TEXAS
Event Country --
Zipcode of the event site 76067
Event Date Year 1990
Event Date Month 6
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport MUNICIPAL
Event Location Nearest Airport ID MWL
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 810 Central Daylight Time
Direction of event from weather observation facility (degrees) 315
Weather Observation Facility ID MWL
Elevation of weather observation facility 910
Distance of event from weather observation facility (units?) 4
Time Zone of the weather observation CDT
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) 20
Air Temperature at event time (in degrees celsius) 24
Dew Point at event time (in degress fahrenheit) 21
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Calm
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 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) 1974
NTSB Notification Source --
NTSB Notification Date Jun 10 1990 12:00AM
NTSB Notification Time 830
Fiche Number and/or location -used to find docket information 43019
Date of most recent change to record Dec 12 2000 5:03PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N3412L
NTSB Number FTW90DPA05
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 GYROFLUG
Aircraft Model SC01B160
Aircraft Series Identifier SC01B160
Aircraft Serial Number S-46
Certified Max Gross Weight 1576
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 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jan 30 1990 12:00AM
Airframe hours since last inspection 90
Airframe Hours 139
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name LITTON APPLIED TECHNOLOGY
Aircraft Owner Street Address 4747 HELLYER AVENUE
Aircraft Owner City SAN JOSE
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 951507012
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) Other Work Use
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 810
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 Approach
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 --