# NTSB MIA91LA141: Bell 47-G, N955B, Aguadilla, PR, May 11, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 11, 1991, 11:15 local (15:15 UTC)
- Place: Aguadilla, PR
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 32866
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA91LA141
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/32866/pdf
- Page: https://openairdocs.org/ntsb/MIA91LA141

## Probable cause

THE IMPROPER IN FLIGHT PLANNING/DECISION OF THE PILOT-IN-COMMAND TO CONDUCT AN OUT-OF-GROUND-EFFECT HOVER WITH A RIGHT CROSSWIND.  THIS RESULTED IN AN IN FLIGHT LOSS OF CONTROL DUE TO SETTLING WITH POWER AND IN FLIGHT COLLISION WITH TERRAIN.

## Sequence of events

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

- Loss of control - in flight, hover
  - weather condition - crosswind (contributing factor)
  - in-flight planning/decision - improper, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - ground

## Analysis

THE HELICOPTER PILOT WAS OBSERVED BY AN NTSB INVESTIGATOR AND A U.S. COAST GUARD PILOT TO CONDUCT AN OUT-OF-GROUND-EFFECT HOVER WITH A RIGHT CROSSWIND IN THE VICINITY OF A PREVIOUS CRASH SITE.  THE HELICOPTER WAS OBSERVED TO MOVE BACKWARDS WHILE DESCENDING WITH A SLOW LEFT TURN.  THE ENGINE RPM WAS HEARD TO INCREASE AS THE HELICOPTER DESCENDED AND COLLIDED WITH THE TERRAIN.  THE HELICOPTER WAS DESTROYED BY FIRE.  THE COMMERCIAL PILOT AND TWO PASSENGERS WERE NOT INJURED. THE PILOT STATED IN AN INTERVIEW THAT HE ENCOUNTERED SETTLING WITH POWER. HE FURTHER STATED HE WAS UNABLE TO INCREASE THE THROTTLE, WHICH WAS NOT SUBSTANTIATED BY EYEWITNESSES WHO HEARD AN INCREASE IN ENGINE RPM PRIOR TO THE COLLISION WITH TERRAIN.

## Aircraft

- Registration: [N955B](https://openairdocs.org/aircraft/N955B), registered now, S/N 711, built 1954 (OpenAirDocs)
- Reported make and model: BELL 47-G
- Registry model: [Bell 47G](https://openairdocs.org/model/bell-47g) (registry code 1181002) (OpenAirDocs)
- Registry engine: [Lycoming VO-435-A1F](https://openairdocs.org/engine/lycoming-vo-435-a1f) (registry code 42200, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 711
- Engines: FRANKLIN 6V-350-A 235 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Esteves, Arturo
- Registered owner: Esteves, Arturo

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; commercial; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 260 total, 220 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 10 knots
- Visibility: 15 statute miles
- Temperature: 82 °F, dew point 70 °F
- Observed at: JBQ, 6 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 19910511015429A](https://openairdocs.org/incident/19910511015429A), May 11, 1991: Bell 47G, Aguadilla, Puerto Rico, Destroyed. Got into settling with power. Impacted ground rolled over.

## Other investigations on N955B (1)

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 MIA89LA229](https://openairdocs.org/ntsb/MIA89LA229), Aug 23, 1989: Bell 47G (N955B), Ponce, PR, substantial damage. Probable cause: FAILURE OF THE AFT TAIL ROTOR DRIVE SHAFT.

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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