# NTSB LAX90LA168: Robinson R22, N9070N, Irvine, CA, May 9, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 9, 1990, 14:50 local (21:50 UTC)
- Place: Irvine, CA
- Location: 33.6695° N, 117.8231° W: Placed by OpenAirDocs: center of Irvine, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=33.6695&lon=-117.8231&mi=10
- Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report November 9, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26798
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90LA168
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26798/pdf
- Page: https://openairdocs.org/ntsb/LAX90LA168

## Probable cause

THE CFI'S FAILURE TO MAINTAIN ROTOR RPM DURING THE PRACTICE AUTOROTATION.

## Sequence of events

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

- Forced landing, descent - emergency
  - autorotation - intentional, pilot in command(cfi)
  - rotor rpm - not maintained, pilot in command(cfi) (cause)
- Hard landing, landing - flare/touchdown
  - altitude - misjudged, pilot in command(cfi) (contributing factor)

## Analysis

DURING AN INSTRUCTIONAL LESSON THE CFI DEMONSTRATED AUTOROTATION TO HIS STUDENT. THE CFI INDICATED THAT HE PLANNED TO LAND IN AN ESTABLISHED LANDING ZONE. HOWEVER, UPON RECOGNIZING THE HELICOPTER WOULD NOT REACH THE DESIRED LOCATION THE CFI DECIDED TO STOP THE DESCENT. THE CFI FURTHER REPORTED THAT HE RAISED THE COLLECTIVE WHICH INDUCED A LOW ROTOR RPM SITUATION. THERE WAS INSUFFICIENT ALTITUDE TO RECOVER AND THE HELICOPTER TOUCHED DOWN HARD.

## Aircraft

- Registration: [N9070N](https://openairdocs.org/deregistered/N9070N-1997-02-05), registration cancelled 1997-02-05, S/N 1513 (OpenAirDocs)
- Reported make and model: ROBINSON R22
- Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs)
- Category: Helicopter
- Serial number: 0186
- Engines: LYCOMING O-320-B2C 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Registered owner: Helistream, Inc.
- Departed: SNA, SANTA ANA, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, unknown; flight hours: 630 total, 550 in this make and model, 426 as pilot in command, 130 in the last 90 days, 56 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 8 knots
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °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 19900509015939A](https://openairdocs.org/incident/19900509015939A), May 9, 1990: Robsin R22BETA, Irvine, CA, Substantial damage. Gave student engine out but student mismanaged collective. CFI took over but rotor RPM too low. Impact chopped tail.

## Other investigations on N9070N (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 LAX96FA185](https://openairdocs.org/ntsb/LAX96FA185), May 1, 1996: Robinson R22 (N9070N), Santa Ana, CA, destroyed. Probable cause: the pilot misjudged the helicopter's distance and altitude and failed to attain the proper descent rate.

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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