# NTSB FTW91LA126: Bell 47D-1, N3575, Provencal, LA, July 24, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 24, 1991, 18:50 local (23:50 UTC)
- Place: Provencal, LA
- Coordinates: 31.649141, -93.200477 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.6491&lon=-93.2005&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 23369
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW91LA126
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23369/pdf
- Page: https://openairdocs.org/ntsb/FTW91LA126

## Probable cause

FUEL LEAKAGE FROM THE FUEL DRAIN VALVE. A FACTOR WAS THE INACCESSIBILITY OF SUITABLE TERRAIN FOR FORED LANDING.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - nonmechanical, maneuvering - aerial application
  - fuel system,drain - leak (cause)
  - fluid,fuel - exhaustion
- Forced landing, descent - emergency
  - terrain condition - none suitable (contributing factor)
- Hard landing, landing - flare/touchdown

## Analysis

A COMMERCIAL HELICOPTER PILOT WAS MANEUVERING HIS AERIAL BURNING EQUIPPED HELICOPTER FOR THE PURPOSE OF BURNING 15 ACRES OF TIMBER. FUEL LEVEL WAS MEASURED TO BE JUST OVER 11 GALLONS OF FUEL REMAINING TO COMPLETE THE 20-30 MINUTE JOB. BASED ON THE FUEL CONSUMPTION OF 13 TO 15 GALLONS PER HOUR, THE AIRCRAFT HAD 40 TO 50 MINUTES OF FUEL REMAINING PRIOR TO DEPARTING. THE ENGINE QUIT 15 MINUTES AFTER DEPARTURE DUE TO FUEL EXHAUSTION. FUEL HAD DRAINED OUT OF THE FUEL CELL SUMP DRAIN VALVE DUE TO FAILURE OR PREMATURE DETERIORATION.

## Aircraft

- Registration: [N3575](https://openairdocs.org/deregistered/N3575-2021-03-06), registration cancelled 2021-03-06, S/N K-7032 (OpenAirDocs)
- Reported make and model: BELL 47D-1
- Registry model: [Bell 47D1](https://openairdocs.org/model/bell-47d1) (registry code 1180802) (OpenAirDocs)
- Registry engine: [Franklin 6V-335 series](https://openairdocs.org/engine/franklin-6v-335-series) (registry code 27039, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: K-7032
- Engines: FRANKLIN 6V-335-A 210 horsepower reciprocating
- Damage: Substantial damage
- Flight: Other work use, Part 137
- Operator: Superior Heli. Of Louisiana
- Registered owner: Superior Heli. Of Louisiana

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; flight hours: 1,481 total, 684 in this make and model, 1,262 as pilot in command, 99 in the last 90 days, 36 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 10 knots
- Visibility: 15 statute miles
- Lowest ceiling: none

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19910724029759A](https://openairdocs.org/incident/19910724029759A), Jul 24, 1991: Bell 47D1, Provencal, LA, Substantial damage. Engine quit on aerial fire burn survey. Landed on slope. Rolled over. Departed minimum fuel. Depleted by leaky sump

## Other investigations on N3575 (3)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB FTW87LA107](https://openairdocs.org/ntsb/FTW87LA107), Apr 25, 1987: Bell 47D1 (N3575), Ardmore, OK, substantial damage
- [NTSB FTW79DPJ37](https://openairdocs.org/ntsb/FTW79DPJ37), Sep 12, 1979: Bell 47D1 (N3575), Ardmore, OK, substantial damage
- [NTSB MIA77DKG08](https://openairdocs.org/ntsb/MIA77DKG08), Dec 12, 1976: Bell 47D1 (N3575), Vanceville, GA, substantial damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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