FLIGHT FINDINGSAVIATION OCCURRENCE MAP
Back to map

FTW99TA194 · Bell 47G-3B-1

17 Jul 1999 · Sour Lake, TX, United States

Bell 47G-3B-1 · Accident: total loss of engine power (non-mechanical) during initial climb

From No airport to an unrecorded destination

Report a problem

Event

NTSB case
FTW99TA194
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

Bell 47G-3B-1

Aircraft type
Bell 47
Category
Helicopter
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
N4002G
Operator
Unknown
Onboard fatalities
Unknown
Route
From No airportTo 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
Initial climb
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
Total loss of engine power (non-mechanical)
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

  • Fuel system, tank › Contamination, water
  • Pilot in command › Aircraft preflight, inadequate

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

NTSB narrative

The helicopter lost engine power during takeoff due to contaminated fuel. The commercial helicopter pilot stated that the night before the accident flight, the fueling truck, which contained three tanks (one each for water, chemicals, and fuel), was checked. The pilot stated that the fuel appeared 'normal' that night. The following day, prior to the accident flight, the helicopter was 'refueled without sumping the tanks.' The pilot added that during takeoff, the engine lost power about 50 feet above the ground, at 30 miles per hour. He executed an autorotation to the ground where the main rotor blades impacted the tail boom and the tail rotor blades contacted the ground. The pilot stated that he found 20 gallons of water in the helicopter's fuel tank after the accident. He added that he discovered the fuel truck had a crack in between the water and fuel tanks. Approximately 80 gallons of water had leaked into the truck's fuel tank. The fuel truck was 'supposed to have an aqua stop filter installed that will not pump if water is present but the wrong filter was installed.'

Probable cause

The pilot's failure to adequately preflight the helicopter's fuel system resulting in the total loss of engine power as a result of water contamination. Factors were the incorrect filter installed on the fueling truck and the pilot's improper touchdown technique.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record FTW99TA194
Event ID
20001212X19285
Case number
FTW99TA194
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: 9ab945520ad9b20764a91b543ce78467da74770164adff4095361dd9548d5232; retrieved 2026-09-22T14:29:10.608Z.