# NTSB CHI94LA142: Bell 47G, N46DH, Springfield, MO, April 27, 1994

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 27, 1994, 10:15 local (15:15 UTC)
- Place: Springfield, MO
- Location: 37.0595° N, 93.2343° W: Placed by OpenAirDocs at Air Park South Airport (2K2), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=37.0595&lon=-93.2343&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report February 24, 1995
- Report: Approved by Office Director
- NTSB case key (mKey): 9513
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA142
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9513/pdf
- Page: https://openairdocs.org/ntsb/CHI94LA142

## Probable cause

the pilot-in-command misjudging the autorotation and improper use of collective.

## Sequence of events

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

- Hard landing, landing - flare/touchdown
  - emergency procedure - simulated, pilot in command(cfi)
  - autorotation - misjudged, pilot in command(cfi) (cause)
  - collective - improper, pilot in command(cfi) (cause)
  - rotor system - underspeed
  - misc rotorcraft,tail boom - sheared

## Analysis

THE PILOT-IN-COMMAND INITIATED A PRACTICE AUTOROTATION FOR A FLIGHT INSTRUCTOR STUDENT DURING A LOW LEVEL (90 FOOT AGL) AGRICULTURAL TURN.  DURING THE FLARE TO LANDING, COLLECTIVE WAS APPLIED EARLY, ROTOR RPM DECAYED AND THE HELICOPTER LANDED WITH A HIGH RATE OF DESCENT.  THE HELICOPTER BOUNCED INTO THE AIR AND PITCHED NOSE DOWN.  BOTH PILOTS APPLIED AFT CYCLIC, RESULTING IN ROTOR BLADE TO FUSELAGE CONTACT, SEVERING THE TAIL BOOM.

## Factual narrative

On April 27, 1994, at 1015 central daylight time, a Bell 47G helicopter, N46DH, operated as a training aircraft by C. R. Hill of Springfield, Missouri, impacted the ground during a practice autorotation at Air Park South, Springfield, Missouri, and was substantially damaged.  The Designated Pilot Examiner/flight instructor and flight instructor student were not injured.  Visual meteorological conditions existed at the time of the accident and no flight plan was filed.  The flight was operated under 14 CFR Part 91 as a flight instructor training flight.

The practice autorotation was initiated during a practice low level agricultural application turn.  According to the pilot, collective input to cushion the landing was made too early, main rotor rpm decayed and the helicopter landed with a high descent rate.  Upon touchdown, the helicopter bounced and pitched nose down.  The pilot in command reported that the combined aft cyclic input by both pilots and blade flexing resulted in rotor blade to fuselage contact, severing the tail boom.

## Aircraft

- Registration: [N46DH](https://openairdocs.org/deregistered/N46DH-1999-04-14), registration cancelled 1999-04-14, S/N VH-2 (OpenAirDocs)
- Reported make and model: BELL 47G
- Registry model: [Bell-Versatile 47G](https://openairdocs.org/model/bell-versatile-47g) (registry code 118100V) (OpenAirDocs)
- Category: Helicopter
- Serial number: VH-2
- Airframe hours: 6745
- Engines: FRANKLIN V6-335 110 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Carlie R. Hill, doing business as Dick Hill
- Registered owner: Carlie R.  Hill
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 1, 1994, 55 hours before
- Airport: 2K2, Air Park South, runway 35, 2,528 × 39 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 46; commercial, flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 20,000 total, 10,000 in this make and model, 19,000 as pilot in command, 30 in the last 90 days, 15 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 40° at 10 knots
- Visibility: 15 statute miles
- Lowest ceiling: 6,500 ft overcast
- Temperature: 52 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: SGF, 12 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 19940427009329A](https://openairdocs.org/incident/19940427009329A), Apr 27, 1994: Bell 47G, Ozark, MO, Substantial damage. During practice autorotation. Cyclic pulled too early. Rotor seed decayed. Hard landing chopped tailboom.

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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