# NTSB LAX91LA307: Robinson R22A, N4070H, El Cerrito, CA, July 11, 1991

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: July 11, 1991, 11:00 local (18:00 UTC)
- Place: El Cerrito, CA
- Location: 37.9196° N, 122.3025° W: Placed by OpenAirDocs: center of El Cerrito, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=37.9196&lon=-122.3025&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed, report March 24, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27287
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA307
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27287/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA307

## Probable cause

THE INSTRUCTOR PILOT'S IMPROPER SLOPE TAKEOFF TECHNIQUE.

## Sequence of events

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

- Roll over, takeoff
  - vertical takeoff - improper, pilot in command(cfi) (cause)
  - procedure inadequate, pilot in command(cfi) (contributing factor)

## Analysis

THE INSTRUCTOR PILOT WAS DEMONSTRATING SLOPE TAKEOFF TECHNIQUES TO THE STUDENT AFTER THE STUDENT HAD LANDED ON A HILLSIDE THAT SLOPED DOWNWARD FROM LEFT TO RIGHT. THE INSTRUCTOR LIFTED THE HELICOPTER'S RIGHT DOWN SLOPE SKID TWICE WHILE THE LEFT SKID REMAINED ON THE GROUND. DURING THE THIRD LIFT-OFF THE INSTRUCTOR DID NOT LIFT THE LEFT SKID AS THE HELICOPTER RAISED AND IT ROLLED OVER UPSLOPE ON ITS LEFT SIDE.

## Aircraft

- Registration: [N4070H](https://openairdocs.org/deregistered/N4070H-2013-10-29), registration cancelled 2013-10-29, S/N 1727, built 1991 (OpenAirDocs)
- Reported make and model: ROBINSON R22A
- 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: 1727
- Engines: LYCOMING O-320 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Para Flite, Inc.
- Registered owner: Akira Mendoza
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, July 9, 1991, 10 hours before
- Departed: RAL, RIVERSIDE, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; commercial, flight instructor; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 420 total, 316 in this make and model, 302 as pilot in command, 205 in the last 90 days, 78 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 9 knots
- Visibility: 3 statute miles
- Lowest ceiling: none
- Altimeter: 29.00 inHg
- Observed at: RAL, 17 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 19910711027089A](https://openairdocs.org/incident/19910711027089A), Jul 11, 1991: Robsin R22ALPHA, El Cerrito, CA, Substantial damage. Student made slope landing. CFI took control tried to raise to hover but rolled over. One skid caught under a rock.

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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