# NTSB LAX91LA182: Robinson R22-BETA, N4066J, Phoenix, AZ, April 20, 1991

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: April 20, 1991, 16:20 local (23:20 UTC)
- Place: Phoenix, AZ
- Coordinates: 33.679492, -112.089164 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.6795&lon=-112.0892&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed, report May 27, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27179
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA182
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27179/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA182

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN MAIN ROTOR RPM.  FACTOR CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S INADEQUATE IN-FLIGHT PLANNING.

## Sequence of events

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

- In flight collision with terrain/water, descent - normal
  - terrain condition - rough/uneven (contributing factor)
  - in-flight planning/decision - inadequate, pilot in command(cfi) (contributing factor)
  - autorotation - simulated, pilot in command(cfi)

## Analysis

THE INSTRUCTOR PILOT ENTERED AN AUTOROTATION WHILE IN CRUISE FLIGHT AT AN ALTITUDE OF 500 FEET ABOVE THE GROUND AND AT AN AIRSPEED OF 60 KNOTS.  THE MAIN ROTOR TACHOMETER DECREASED BELOW ITS MINIMAL RANGE FOR FLIGHT WHEN THE HELICOPTER ENTERED THE AUTOROTATION.  THE INSTRUCTOR PILOT CONTINUED THE AUTOROTATIVE DESCENT UNTIL PASSING 150 FEET ABOVE GROUND LEVEL BEFORE INITIATING A POWER RECOVERY.  THE MAIN ROTOR RPM DID NOT INCREASE AND THE AIRCRAFT COLLIDED WITH GROUND.

## Aircraft

- Registration: [N4066J](https://openairdocs.org/deregistered/N4066J-2003-03-06), registration cancelled 2003-03-06, S/N 1506, built 1990 (OpenAirDocs)
- Reported make and model: ROBINSON R22-BETA
- Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1506
- Engines: LYCOMING O-320-B2C 131 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Avcon, Inc.
- Registered owner: Catalina Helicopters
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, January 2, 2000

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 2,261 total, 1,750 in this make and model, 2,115 as pilot in command, 233 in the last 90 days, 84 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 260° at 10 knots
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point 34 °F
- Altimeter: 29.00 inHg
- Observed at: DVT, 4 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 19910420011679A](https://openairdocs.org/incident/19910420011679A), Apr 20, 1991: Robsin R22BETA, Phoenix, AZ, Substantial damage. Collided with the terrain while demonstrating an autorotation. Pilot stated main rotor RPM remained at 85 per cent.

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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