# NTSB FTW87LA069: Bell 47G, N6330D, Sand Springs, OK, February 23, 1987

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 23, 1987, 13:45 local (19:45 UTC)
- Place: Sand Springs, OK
- Coordinates: 36.130149, -96.130332 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.1301&lon=-96.1303&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 2, 1988
- Report: Approved by Office Director
- NTSB case key (mKey): 22333
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW87LA069
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/22333/pdf
- Page: https://openairdocs.org/ntsb/FTW87LA069

## Sequence of events

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

- Loss of control - in flight, takeoff - initial climb
  - weather condition - unfavorable wind (cause)
  - compensation for wind conditions - inadequate, dual student (cause)
  - weather condition - tailwind (cause)
  - remedial action - attempted, pilot in command(cfi)
  - climb - not possible, pilot in command(cfi) (cause)
- In flight collision with object, descent
  - object - tree(s) (cause)
- In flight collision with terrain/water, descent - uncontrolled
- Roll over, landing - flare/touchdown

## Analysis

INSTRUCTOR PLT WAS DEMONSTRATING A CONFINED AREA TAKEOFF TO THE PVT PLT TAKING ADVANCE INSTRUCTION. AS THE ACFT CLEARED THE BARRIERS, THE QUARTERING HEAD WIND SHIFTED TO A TAIL WIND AND THE ACFT LOST TRANSLATIONAL LIFT. APPLICATION OF FULL POWER DID NOT REMEDY THE SITUATION AND THE ACFT LOST ROTOR RPM. ACFT SETTLED INTO THE TREES BEFORE THE INSTRUCTOR COULD REESTABLISH A CLIMB. A TAIL WIND WOULD SUBSTANTIALLY INCREASE THE POWER REQUIREMENT FOR THE MANEUVER THAT WAS BEING ATTEMPTED.

## Aircraft

- Registration: N6330D (not matched to a registry record)
- Reported make and model: BELL 47G
- Category: Helicopter
- Serial number: 1044
- Airframe hours: 6480
- Engines: FRANKLIN 6VS-335 SER 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Allied Helicopter Services,Inc
- Registered owner: Allied Helicopter Services Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 12, 1986, 172 hours before
- Departed: 5F2, TULSA, OK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: helicopter, airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 5,099 total, 237 in this make and model, 4,725 as pilot in command, 86 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 170° at 13 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 55 °F, dew point 30 °F
- Altimeter: 30.00 inHg
- Observed at: TUL, 15 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 19870223003169A](https://openairdocs.org/incident/19870223003169A), Feb 23, 1987: Bell 47G, Sand Springs, OK, Substantial damage. The helicopter encountered a wind shift on takeoff. The aircraft landed hard and rolled over.

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.