- Date
- May 20, 1998, 09:15 local (15:15 UTC)
- Place
- Idaho Falls, ID
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N1009TAir Tractor AT-401
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 12, 2000
- Report
- Approved by Office Director
- FAA report
- 19980520010249A
- Case key
- 42789
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The NTSB’s determination of the probable cause, and any contributing factors.
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.
Analysis
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.
Factual narrative
On May 20, 1998, approximately 0915 mountain daylight time, an Air Tractor AT-401, N1009T, collided with a power transmission line during an aerial application flight about two miles northwest of Idaho Falls, Idaho. The commercial pilot, who was the sole occupant, received minor injuries, and the aircraft, which was owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 137 flight, which originated at an agricultural airstrip near Osgood, Idaho, was being operated in visual meteorological conditions.
According to the pilot, who had been maneuvering near the power line while applying chemicals to a field, he was just rolling wings-level and descending for another pass when his left wing contacted the top wire of a power line located just beyond the boundary of the field he was spraying. 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.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Aircraft
- Registration
- N1009T
- Reported as
- Air Tractor AT-401
- Category
- Airplane
- Serial number
- 401-0707
- Airframe hours
- 4,055
- Engine
- P&W 1340-AN2, 600 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Aerial application · Part 137
- Registered owner
- Orlin D. Lewis
- Airworthiness certificate
- Special, Restricted (Special)
- Last inspection
- 100 hour · April 21, 1998 · 9 hours before
- Departed
- Osgood, ID
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 53
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Center
- Flight hours
- 9,882 total · 9 in this make and model · 9,761 as pilot in command · 12 in the last 90 days · 9 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 50° at 7 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 50 °F
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N1009T · 1
Matched to the same aircraft by N-number and date.