# NTSB FTW89LA092: Bell 47L, N6330D, Tulsa, OK, May 6, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 6, 1989, 10:30 local (15:30 UTC)
- Place: Tulsa, OK
- Coordinates: 36.189579, -95.990913 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.1896&lon=-95.9909&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 22, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 22862
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW89LA092
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/22862/pdf
- Page: https://openairdocs.org/ntsb/FTW89LA092

## Probable cause

INADEQUATE SUPERVISION OF THE STUDENT BY THE INSTRUCTOR IN THAT HE ALLOWED THE STUDENT TO OVERPOWER HIS CONTROL INPUTS AFTER AN UNEXPECTED GUST OF WIND MOVED THE TAIL OF THE HELICOPTER.

## 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 - gusts (contributing factor)
  - relinquishing of control - not understood, dual student (cause)
  - supervision - inadequate, pilot in command(cfi) (cause)
- In flight collision with terrain/water, hover

## Analysis

THE INSTRUCTOR PILOT SAID HE AND A BEGINNER STUDENT WERE IN A HOVER PRACTICE AREA AND WERE REPOSITIONING THE HELICOPTER TO ALLOW ANOTHER HELICOPTER TO HOVER OUT FROM THE RAMP. HE SAID HE ALLOWED THE STUDENT TO FOLLOW HIM ON THE CONTROLS, AND DURING THE HOVER LANDING, A GUST OF WIND CAUSED THE TAIL TO PITCH UP. AN UNEXPECTED CONTROL INPUT BY THE STUDENT CAUSED AN OVERCORRECTION WHICH ALLOWED THE TAIL ROTOR TO STRIKE THE GROUND. THERE WAS DAMAGE TO THE TAIL ROTOR, THE SKIDS, AND THE BUBBLE CANOPY.

## Aircraft

- Registration: N6330D (not matched to a registry record)
- Reported make and model: BELL 47L
- Category: Helicopter
- Serial number: 1044
- Airframe hours: 7377
- Engines: FRANKLIN 6V-335-A 210 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Allied Helicopters, Inc.
- Registered owner: Allied Helicopter Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 2, 1989
- Departed: 5F2
- Airport: 5F2, Downtown Airpark

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 6,448 total, 950 in this make and model, 6,013 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 10 knots, gusting 15
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 75 °F

## FAA reports on this event (1)

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

- [Incident 19890506011089I](https://openairdocs.org/incident/19890506011089I), May 6, 1989: Bell 47G, Tulsa, OK, Minor damage. On hover after liftoff encountered strong gust. In controlling aircraft tail rotor hit ground. Made hard landing.

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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