# NTSB LAX91LA357: Robinson R22B, N4037A, Chandler, AZ, August 13, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 13, 1991, 13:40 local (20:40 UTC)
- Place: Chandler, AZ
- Coordinates: 33.319755, -111.870758 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.3198&lon=-111.8708&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report May 3, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27326
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA357
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27326/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA357

## Probable cause

THE FAILURE OF THE STUDENT PILOT TO MAINTAIN ADEQUATE CONTROL OF THE HELICOPTER AND STOP A DESCENT, WHILE MANEUVERING. THE PILOT'S DISORIENTATION WAS A CONTRIBUTING FACTOR.

## Sequence of events

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

- In flight collision with terrain/water, maneuvering
  - aircraft control - inadequate, pilot in command (cause)
  - descent - not corrected, pilot in command (cause)
  - spatial disorientation, pilot in command (contributing factor)

## Analysis

THE STUDENT PILOT WAS PRACTICING MANEUVERS IN A LOCAL PRACTICE AREA. HE SAID THAT WHILE PERFORMING SOME TURNS, HE LOST HIS ORIENTATION, BECAME 'DIZZY,' AND THE HELICOPTER HIT THE GROUND HARD, THEN ROLLED OVER. THE HELICOPTER WAS EXAMINED AND NO PREIMPACT MECHANICAL MALFUNCTION OR FAILURE WAS IDENTIFIED.

## Aircraft

- Registration: N4037A (not matched to a registry record)
- Reported make and model: ROBINSON R22B
- Category: Helicopter
- Serial number: 1561
- Engines: LYCOMING O-320 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Arizona Wing & Rotor, Inc.
- Registered owner: Arizona Wing & Rotor, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, January 2, 2000

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; student; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 63 total, 63 in this make and model, 5 as pilot in command, 63 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 4 knots, gusting 10
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 106 °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).

- [Accident 19910813033949A](https://openairdocs.org/incident/19910813033949A), Aug 13, 1991: Robsin R22BETA, Chandler, AZ, Substantial damage. Lost tail rotor effect maneuvering. Spun to right. Recovered but panicked and dizzy,landed hard. Helicopter rolled.

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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