Aircraft Accident/Incident Report

Rock, Kansas 67161
Wednesday, November 4, 1998 20:58 CST

NTSB Narrative Summary Released at Completion of Accident

The airplane's left engine had been overhauled and required an in-flight Negative Torque Sensing (NTS) check. The procedures required that the left engine be shut down during the test flight. The test flight was conducted at night. The pilots were briefed that there was icing and moderate rime icing mixed below 15,000 feet in clouds and precipitation. The cloud bases were between 2,500 to 2,900 feet agl. After departure, the pilot reported to ATC that they were clear and on top of the clouds at about 6,500 feet msl. N5LN was assigned a 180 degree heading at an assigned altitude of 8,000 feet. Without notification to ATC, N5LN turned to a southeast heading, descended from 7,700 feet to about 5,500 feet, and decelerated from about 182 kts to about 138 kts. ATC assigned N5LN a block altitude of 6,000 to 8,000 feet and a VFR-On-Top clearance. ATC instructed N5LN to turn right to stay in the assigned airspace. N5LN turned right but continued to descend from about 5,500 feet to the last radar indication of 4,500 feet. The airplane impacted the ground in a steep attitude. The inspection of the wreckage indicated the landing gear was down, and with full right rudder trim and about six degrees nose up trim. The examination of the engines indicated both engines were rotating and operating at the time of impact. The examination of the airframe and propellers found no pre-existing anomalies that would have precluded normal operation.

NTSB Probable Cause Narrative

the pilot failed to maintain control of the aircraft and made an improper evaluation of the weather. Additional factors were flying a test flight at night with the icing conditions in the clouds.

Event Information

Type of Event Accident
Event Date 11/4/1998
Event Day of the Week Wednesday
Time of Event 2058
Event Time Zone Central Standard Time
Event City ROCK
Event State KANSAS
Event Country --
Zipcode of the event site 67161
Event Date Year 1998
Event Date Month 11
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 Full
Investigator's weather source Weather Observation Facility
Time of the weather observation 2056 Central Standard Time
Direction of event from weather observation facility (degrees) 350
Weather Observation Facility ID ICT
Elevation of weather observation facility 1332
Distance of event from weather observation facility (units?) 22
Time Zone of the weather observation CST
Lighting Conditions Night/Dark
Lowest Ceiling Height 2500
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 9
Air Temperature at event time (in degrees celsius) 38
Dew Point at event time (in degress fahrenheit) 33
Wind Direction (degrees magnetic) 200
Variable Wind Indicator Unknown
Wind Speed (knots) 6
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 0
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 2
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 1984
NTSB Notification Source --
NTSB Notification Date Nov 5 1998 12:00AM
NTSB Notification Time 1100
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Aug 13 2001 3:36PM
User who most recently changed record JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N5LN
NTSB Number CHI99FA023
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Mitsubishi
Aircraft Model MU-2B-60
Aircraft Series Identifier MU-2B-60
Aircraft Serial Number 799SA
Certified Max Gross Weight 11575
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 9
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Jul 30 1998 12:00AM
Airframe hours since last inspection 30
Airframe Hours 4712
ELT Installed Yes
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name L. W. AVIATION
Aircraft Owner Street Address 530 N. LORRAINE ST.
Aircraft Owner City WICHITA
Aircraft Owner State KS
Aircraft Owner Country
Aircraft Owner Zipcode 67214
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) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code 3AU
Departure City AUGUSTA
Departure State KS
Departure Country
Departure Time 2035
Departure Time Zone CST
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 --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jul 25 2001 4:05AM
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 --