# NTSB LAX87LA294: Bell 47D-1, N917B, Taft, CA, August 5, 1987

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 5, 1987, 15:15 local (22:15 UTC)
- Place: Taft, CA
- Coordinates: 35.160209, -119.429779 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.1602&lon=-119.4298&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 31, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 25659
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX87LA294
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25659/pdf
- Page: https://openairdocs.org/ntsb/LAX87LA294

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, cruise - normal
  - maintenance - improper, pilot in command (contributing factor)
  - fluid,fuel - exhaustion (cause)
  - fuel consumption calculations - inaccurate, pilot in command (cause)
- Forced landing, descent - emergency
  - autorotation
- Airframe/component/system failure/malfunction, landing - flare/touchdown
  - flight controls - improper use of, pilot in command (cause)

## Analysis

THE PLT RPRTD THE ENG LOST POWER AT ABOUT 300' AGL AFTER THE HELICOPTER HAD FLOWN APRX 2.7 HRS WITHOUT REFUELING. HE INITIATED AN AUTOROTATIVE LANDING; HOWEVER, BEFORE TOUCHDOWN, THE MAIN ROTOR BLADES CONTACTED & SEVERED THE TAIL BOOM. AN EXAM REVEALED THE FUEL TANK WAS EMPTY. NO SIGNS OF FUEL LEAKAGE WERE FOUND. THE HELICOPTER HAD BEEN EQUIPPED WITH A 210 HP FRANKLIN ENG IAW A SUPPLEMENTAL TYPE CERTIFICATE. THERE WAS NO FACTORY DATA ON FUEL CONSUMPTION RATES FOR THIS CONFIGURATION. OTHER OPERATORS, WHO OPERATED THIS MAKE & MODEL OF HELICOPTER, ESTIMATED THE FUEL CONSUMPTION WAS APRX 12 GAL/HR. AFTER THE ACDNT, THE PLT RPRTD HE MEASURED THE FUEL CAPACITY OF THE HELICOPTER FUEL CELL. HE STATED THE CELL WOULD HOLD ONLY 26.5 GAL OF FUEL, INSTEAD OF '29' AS INDCD BY A STICK-ON MARKER THAT HAD BEEN INSTALLED ON A PREVIOUSLY PAINTED PLACARD.

## Aircraft

- Registration: [N917B](https://openairdocs.org/aircraft/N917B), registered now, S/N 606, built 1952 (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 6V4 series](https://openairdocs.org/engine/franklin-6v4-series) (registry code 27033, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 606
- Airframe hours: 63465
- Engines: FRANKLIN 6V4 210 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Registered owner: Helt Engineering Inc
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, July 1, 1987, 767 hours before
- Departed: BFL, BAKERSFIELD, CA
- Destination: L17, TAFT, CA
- Airport: Taft

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 1,913 total, 474 in this make and model, 1,677 as pilot in command, 169 in the last 90 days, 91 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 12 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 63 °F
- Altimeter: 29.00 inHg
- Observed at: BFL, 25 nm away

## 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 19870805082279A](https://openairdocs.org/incident/19870805082279A), Aug 5, 1987: Bell STC47, Taft, CA, Substantial damage. Lost all power. In autorotation heard bang. Aft part of tailboom severed by main rotors. Pilot moved cylic too fast

## Other investigations on N917B (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 LAX88LA160](https://openairdocs.org/ntsb/LAX88LA160), Apr 13, 1988: Bell 47D1 (N917B), Taft, CA, substantial damage
- [NTSB LAX76FUQ32](https://openairdocs.org/ntsb/LAX76FUQ32), Apr 7, 1976: Bell 47D-1 (N917B), Lancaster, CA, substantial damage
- [NTSB SEA65A0044](https://openairdocs.org/ntsb/SEA65A0044), Feb 23, 1965: Bell 47D1 (N917B), Roseburg, OR, 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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