# NTSB CHI93LA340: Robinson R22, N9071S, Bethalto, IL, August 27, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 27, 1993, 17:45 local (22:45 UTC)
- Place: Bethalto, IL
- Coordinates: 38.900798, -90.039901 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.9008&lon=-90.0399&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report July 25, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 9296
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI93LA340
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9296/pdf
- Page: https://openairdocs.org/ntsb/CHI93LA340

## Probable cause

the pilot-in-command's not maintaining rotor RPM.

## Sequence of events

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

- Loss of engine power(partial) - nonmechanical, approach - vfr pattern - base leg/base to final
  - rotor rpm - not maintained, pilot in command (cause)
  - powerplant controls - improper use of, pilot in command
- Forced landing, descent - emergency
  - autorotation - initiated, pilot in command
- Roll over, landing - flare/touchdown
  - terrain condition - crop

## Analysis

THE PILOT WAS PRACTICING TAKEOFFS AND LANDINGS. HE REPORTED THAT ROTOR RPM DROPPED AND HE CONDUCTED AN AUTOROTATIONAL LANDING INTO A CROP FIELD ADJACENT TO THE AIRPORT.  EXAMINATION OF THE HELICOPTER AFTER THE ACCIDENT FAILED TO REVEAL ANY PRE-EXISTING ANOMALIES.

## Factual narrative

On August 27, 1993, at 1745 central daylight time, a Robinson R22, N9071S, registered to Charles E. Duchek of Pacific, Missouri, and operated by a commercial rated pilot experienced a loss of rotor RPM and impacted the terrain while turning final to runway 17 at Alton, Illinois.  The helicopter sustained substantial damage.  The pilot reported no injuries. The personal 14 CFR Part 91 flight was operating in visual meteorological conditions.  No flight plan was on file.  The local flight departed Alton, Illinois, exact time unknown.

The pilot stated that on turning from base to final for runway 17, he noted a low rotor RPM indication and initiated an autorotation landing adjacent to the runway in a crop field.

A port accident examination conducted by Federal Aviation Administration inspectors failed to reveal any pre-accident anomalies with the helicopter.

## Aircraft

- Registration: [N9071S](https://openairdocs.org/deregistered/N9071S-1994-08-24), registration cancelled 1994-08-24, S/N 0195 (OpenAirDocs)
- Reported make and model: ROBINSON R22
- Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs)
- Category: Helicopter
- Serial number: 0195
- Airframe hours: 2792
- Engines: LYCOMING O-320-A2C 124 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Duchek, Charles E.
- Registered owner: Duchek, Charles E.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 30, 1993, 67 hours before
- Departed: ALN
- Destination: ALN
- Flight plan: VFR
- Airport: ALN, Saint Louis Regional, runway 17, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 51; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 1,080 total, 57 in this make and model, 1,235 as pilot in command, 51 in the last 90 days, 33 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 250° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 91 °F, dew point 73 °F
- Altimeter: 30.00 inHg
- Observed at: ALN

## 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 19930827031629A](https://openairdocs.org/incident/19930827031629A), Aug 27, 1993: Robsin R22, Alton/St Louis, IL, Substantial damage. Rotor speed decayed on approach. Autorotated to crop field. Hard landing caused 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.

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