Aircraft Accident/Incident Report

Idaho Falls, Idaho 83406
Wednesday, May 20, 1998 9:15 MDT

NTSB Narrative Summary Released at Completion of Accident

According to the pilot, who was maneuvering near the power line while applying chemicals to a field, he had just rolled wings-level and descended for another pass when his left wing contacted the top wire of the power line. He said that he saw the line and thought he had clearance, but the aircraft's wing caught the wire near its tip. He reported that after colliding with the power line, the aircraft struck the ground in a 'cart-wheeling' motion. He further stated that he was accustomed to flying the AT-300, but that he had recently purchased the AT-401, and that this was his first application flight using the new aircraft. It was his opinion that the different size and sight-picture of the 401 had caused him to think he had more clearance from the wire than he actually had.

NTSB Probable Cause Narrative

The pilot's failure to maintain clearance from a power transmission line during an aerial application flight. Factors include a power line located just beyond the boundary of the field being sprayed, and the pilot's incorrect judgement of the distance between the wire and his aircraft.

Event Information

Type of Event Accident
Event Date 5/20/1998
Event Day of the Week Wednesday
Time of Event 915
Event Time Zone Mountain Daylight Time
Event City IDAHO FALLS
Event State IDAHO
Event Country --
Zipcode of the event site 83406
Event Date Year 1998
Event Date Month 5
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 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) 10
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 50
Variable Wind Indicator Unknown
Wind Speed (knots) 7
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 Minor
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 1
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 261
NTSB Notification Source --
NTSB Notification Date May 20 1998 12:00AM
NTSB Notification Time 1000
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 11:24AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1009T
NTSB Number SEA98LA080
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Air Tractor
Aircraft Model AT-401
Aircraft Series Identifier AT-401
Aircraft Serial Number 401-0707
Certified Max Gross Weight 6000
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 100 Hour
Date of Last Inspection Apr 21 1998 12:00AM
Airframe hours since last inspection 9
Airframe Hours 4055
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ORLIN D. LEWIS
Aircraft Owner Street Address P.O. BOX 6
Aircraft Owner City LEWISVILLE
Aircraft Owner State ID
Aircraft Owner Country
Aircraft Owner Zipcode 83431
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 HNBG
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Agriculture
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Aerial Application
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code
Departure City OSGOOD
Departure State ID
Departure Country
Departure Time 830
Departure Time Zone MDT
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 Jan 2 2001 10:34AM
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 --