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Accidents · NTSB SEA91LA109 · Final report

Bell 47G-3B-1 accident near Malott, Washington, May 19, 1991

On May 19, 1991 at about 4:21 pm local time, a Bell 47G-3B-1 (helicopter), registered N73903, was destroyed in an accident near Malott, Washington. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

AN UNDETERMINED FAILURE OF THE FUEL PUMP CASING RESULTING IN AN IN FLIGHT FIRE AND LOSS OF ENGINE POWER.

Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.

What the record shows

Date
May 19, 1991 · about 4:21 pm local time
Place
Malott, Washington · map
Type
Accident
Injuries
No one was hurt; 1 person was on board or involved.
Weather
visual conditions (good weather)
Aircraft
Bell 47G-3B-1 · all 47G-3B-1s on the register
Registration
N73903 · registry record · serial 2883
Damage
Destroyed
Flight
Aerial application (crop spraying) flight · agricultural flying rules (Part 137)

The NTSB's narrative final · quoted from the NTSB record

DURING AN AERIAL APPLICATION FLIGHT, THE ENGINE SUDDENLY LOST POWER. THE PILOT TRIED TO MANEUVER TO AN OPEN AREA, HOWEVER, THE HELICOPTER COLLIDED WITH TREES. POST CRASH INVESTIGATION REVEALED THAT THE HELICOPTER EXPERIENCED AN IN FLIGHT FIRE. IT WAS FOUND THAT A SECTION OF THE AUXILIARY FUEL PUMP CASING BROKE AWAY IN THE AREA WHERE THE FUEL LINE FITTING SCREWS INTO THE PUMP. DUE TO FIRE DAMAGE, USEFUL FACTURE TOPOGRAPHY TO DETERMINE THE MODE OF FAILURE WAS DESTROYED.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record from the NTSB's investigation tables, in plain English

Pilot

  • Certificate: commercial pilot
  • Ratings: single-engine land; rotorcraft: helicopter
  • Flight time: 2,974 hours in all; 1,150 in this make and model; 96 in the last 90 days; 49 in the last 30 days; 2,924 as pilot in command
  • Medical certificate: Class 2 (valid medical--no waivers/lim.)
  • Seat: unk

The aircraft

  • Last inspection: inspection type not recorded; 0 hours since
  • Maximum gross weight: 2,950 lb
  • Seats: 3
  • Landing gear: fixed
  • Engine: Lycoming TVO-435-A1A (piston); 0 hours total

The flight

  • Flight plan: none
  • Runway 0

Weather at the time

  • Light: daylight
  • Visibility: 12 statute miles
  • Sky: overcast at 2,500 ft; not recorded
  • Temperature: 0°F (-18°C), dew point 0°F (-18°C)

Injuries

FatalSeriousMinorNone
Crew1

Documents from the investigation the NTSB's docket: the evidence folder behind the report

The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.

Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.