# NTSB LAX90LA204: Robinson R22A, N8557Z, Torrance, CA, May 30, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 29, 1990, 19:00 local (May 30, 1990, 02:00 UTC)
- Place: Torrance, CA
- Coordinates: 33.799728, -118.350875 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.7997&lon=-118.3509&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report December 14, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26828
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90LA204
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26828/pdf
- Page: https://openairdocs.org/ntsb/LAX90LA204

## Probable cause

THIS ACCIDENT WAS A DYNAMIC ROLL OVER DUE TO THE RIGHT SKID ENCOUNTERING SOFT SOIL DURING THE FORCED LANDING.

## Sequence of events

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

- Loss of engine power, landing
  - autorotation - simulated, pilot in command(cfi)
  - reason for occurrence undetermined (cause)
- Forced landing, descent - normal
- Roll over, landing - roll
  - terrain condition - soft (contributing factor)

## Analysis

ACCORDING TO STATEMENTS FROM BOTH THE INSTRUCTOR AND THE STUDENT, FOUR PRACTICE AUTOROTATIONS HAD ALREADY BEEN PERFORMED WITH POWER RECOVERIES PRIOR TO TOUCH DOWN. THE PILOTS NOTED THAT THE FIFTH AUTOROTATION PROCEEDED NORMALLY UNTIL ABOUT 40 FEET AGL WHEN THROTTLE AND COLLECTIVE WAS ADDED TO BEGIN THE POWER RECOVERY. ACCORDING TO BOTH PILOTS STATEMENTS, THE ENGINE DID NOT RESPOND WHEN THE THROTTLE WAS INCREASED. THE HELICOPTER TOUCHED DOWN HARD, SLID ALONG THE GROUND AND ROLLED OVER ON ITS RIGHT SIDE AFTER THE RIGHT SKID ENCOUNTERED SOFT SOIL. THE ENGINE AND HELICOPTER WERE EXAMINED WITH NO EVIDENCE OF A SYSTEM FAILURE OR MALFUNCTION. THE ENGINE WAS STARTED IN THE HELICOPTER AND RUN FOR 10 MINUTES. DURING THE TEST RUN, THE ENGINE WAS CYCLED THROUGHOUT ITS NORMAL OPERATING RANGE.

## Aircraft

- Registration: [N8557Z](https://openairdocs.org/deregistered/N8557Z-2017-03-24), registration cancelled 2017-03-24, S/N 0464, built 1985 (OpenAirDocs)
- Reported make and model: ROBINSON R22A
- Registry model: [Robinson Helicopter R22 ALPHA](https://openairdocs.org/model/robinson-helicopter-r22-alpha) (registry code 7640104) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 464
- Engines: LYCOMING O-320-B2C 124 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Rolling Hills Aviation, Inc.
- Registered owner: Rolling Hills Aviation, Inc
- Departed: TOA
- Destination: TOA
- Airport: TOA, Torrance

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; flight instructor, commercial; medical: class 1, valid medical--no waivers/lim.; flight hours: 645 total, 628 in this make and model, 594 as pilot in command, 360 in the last 90 days, 135 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 54 °F
- Altimeter: 29.00 inHg
- Observed at: TOA

## 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 19900529017849A](https://openairdocs.org/incident/19900529017849A), May 29, 1990: Robsin R22ALPHA, Torrance, CA, Substantial damage. On fifth practice autorotation with power recovery engine was out. Made hard low rotor RPM landing. Carb ice factor

## Other investigations on N8557Z (1)

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.

- [NTSB FTW02LA080](https://openairdocs.org/ntsb/FTW02LA080), Feb 11, 2002: Robinson R-22A (N8557Z), Encino, TX, substantial damage. Probable cause: The pilot's failure to maintain aircraft control during lift off from a transport trailer resulting in dynamic rollover of the helicopter.

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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