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SEA99LA075 · Air Tractor AT-401

27 May 1999 · Jerome, ID, United States

Air Tractor AT-401 · Accident: loss of engine power en route

From U73 · Jerome, ID to an unrecorded destination

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Event

NTSB case
SEA99LA075
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Air Tractor AT-401

Aircraft type
Air Tractor AT-401
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N6024M
Operator
Spray Craft
Onboard fatalities
Unknown
Route
From U73 · Jerome, IDTo not recorded
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 137: Agricultural
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
En route · cruise
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Loss of engine power
Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
Fuel exhaustion
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Fluid, fuel › Exhaustion

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The pilot departed the airport, with approximately 75 gallons of fuel on board, and flew approximately 19 miles to the spray location. Approximately 45 minutes into the flight, the pilot noticed the fuel quantity gauge indication was decreasing at a higher than normal rate, and he elected to return to the airport. Eight miles from the airport, the aircraft began to lose power and the pilot elected to initiate a forced landing in an open field. During the landing roll, the aircraft struck a lava bed, causing substantial damage to the aircraft. An FAA inspector inspected the aircraft and reported that there was no evidence of fuel in the aircraft's fuel tanks. He also stated there was no evidence of a preexisting fuel leak. Post-accident inspection of the aircraft's carburetor revealed that the mixture control back-suction bleed tube in the carburetor bowl assembly was plugged. According to the certificate holder of the carburetor, a blockage of the mixture control back-suction bleed tube would result in a rich mixture situation. Normal fuel consumption for this aircraft is 32 gallons to 35 gallons per hour.

Probable cause

Fuel exhaustion. Carburetor contamination and rough terrain were factors.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record SEA99LA075
Event ID
20001212X18899
Case number
SEA99LA075
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 733532e2389df8e282ee61e81548d6f0c5af9148a217fef9433289adda4467c8; retrieved 2026-09-22T15:03:51.762Z.