# NTSB FTW85LA043: Bell 47D1, N93067, Terlingua, TX, November 4, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: November 3, 1984, 18:00 local (Nov 4, 1984, 00:00 UTC)
- Place: Terlingua, TX
- Coordinates: 29.319232, -103.619842 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.3192&lon=-103.6198&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21621
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW85LA043
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21621/pdf
- Page: https://openairdocs.org/ntsb/FTW85LA043

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, cruise
  - fluid,fuel - water (cause)
  - aircraft preflight - improper, pilot in command (cause)
- Forced landing, landing
  - autorotation - performed, pilot in command
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - rough/uneven (contributing factor)

## Analysis

SHORTLY AFTER THE PLT TOOK OFF ON A SIGHT-SEEING FLT, THE ENG LOST POWER WHEN THE HELICOPTER WAS OVER ROUGH TERRAIN AT ABOUT 200 FT AGL. DURING AN AUTOROTATIVE LANDING, THE HELICOPTER ROCKED FORWARD CAUSING THE MAIN ROTOR BLADES TO STRIKE THE TAIL BOOM. ACCORDING TO THE PLT, THE POWER LOSS WAS DUE TO A SMALL AMOUNT OF WATER IN THE FUEL.

## Aircraft

- Registration: [N93067](https://openairdocs.org/aircraft/N93067), registered now, S/N 5501, built 1965 (OpenAirDocs)
- Reported make and model: BELL 47D1
- 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: 5501
- Engines: LYCOMING VO-435 reciprocating
- Damage: Substantial damage
- Flight: Part 91
- Operator: Patrick Q Perez
- Registered owner: Hoffmann Aircraft Inc
- Airworthiness certificate: Standard, Normal

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land, multi-engine sea, single-engine sea; instrument ratings: airplane, helicopter; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 18,288 total, 44 in this make and model, 62 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 10 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 19841103061509A](https://openairdocs.org/incident/19841103061509A), Nov 3, 1984: Bell 47D1, Terlingua, TX, Minor damage. Engine quit, water contamination. Main rotor struck tail boom on landing due to low rpms and rocking motion.

## Other investigations on N93067 (5)

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 ERA14LA099](https://openairdocs.org/ntsb/ERA14LA099), Jan 21, 2014: Bell 47D1 (N93067), Pell City, AL, substantial damage. Probable cause: The pilot’s use of an improper clutch engagement procedure, which resulted in clutch glazing, slippage, and, ultimately, the in-flight disengagement of the clutch and a loss of rotor rpm.…
- [NTSB MIA92LA069](https://openairdocs.org/ntsb/MIA92LA069), Jan 27, 1992: Bell 47D1 (N93067), Cross City, FL, substantial damage. Probable cause: PARTIAL LOSS OF ENGINE POWER DUE TO UNDETERMINED REASONS AND UNSUITABLE TERRAIN ENCOUNTERED DURING THE AUTOROTATIVE LANDING.
- [NTSB MIA90LA023](https://openairdocs.org/ntsb/MIA90LA023), Nov 2, 1989: Bell 47D1 (N93067), Loxahatchee, FL, substantial damage. Probable cause: FAILURE OF THE PILOT TO MAINTAIN ROTOR RPM AFTER PULLING UP FROM A SWATH RUN. A RELATED FACTOR WAS THE PRESENCE OF TREES.
- [NTSB FTW82DA189](https://openairdocs.org/ntsb/FTW82DA189), May 20, 1982: Bell 47D-1 (N93067), Harrisburg, AR, substantial damage
- [NTSB LAX67A0026](https://openairdocs.org/ntsb/LAX67A0026), Sep 1, 1966: Bell 47D1 (N93067), Quartz Hill, CA, 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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.