# NTSB LAX88FA032: Robinson R22A, N8475A, Moraga, CA, November 3, 1987

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: November 3, 1987, 13:38 local (21:38 UTC)
- Place: Moraga, CA
- Coordinates: 37.829551, -122.099006 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.8296&lon=-122.0990&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report April 2, 1996
- Report: Approved by Office Director
- NTSB case key (mKey): 25787
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX88FA032
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25787/pdf
- Page: https://openairdocs.org/ntsb/LAX88FA032

## Probable cause

A DIVERGENCE OF THE MAIN ROTOR FROM ITS NORMAL PLANE OF ROTATION FOR AN UNDETERMINED REASON, WHICH RESULTED IN ROTOR CONTACT WITH THE COCKPIT AREA.

## Sequence of events

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

- Loss of control - in flight, hover
  - reason for occurrence undetermined (cause)
  - rotor system,main rotor - diverged
- Airframe/component/system failure/malfunction, hover
  - fuselage,cabin - blade strike
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE STUDENT WAS ON A DUAL FLIGHT, REVIEWING MANEUVERS & PROCEDURES TO REVALIDATE AN EXPIRED CFI CERTIFICATE. AN EXAM OF HIS LOG REVEALED THAT ON THE LAST 2 FLIGHTS, HE OCCUPIED THE LEFT PILOT SEAT & PRACTICED TEACHING QUICK STOPS, HOVERING AUTOROTATIONS, LOW ROTOR RPM RECOVERY & THROTTLE CUTS. WITNESSES SAID THE HELICOPTER HAD BEEN WORKING THE AREA ABOUT 20 MIN NEAR A HILL TOP.  THEY SAID THE HELICOPTER WAS HOVERING 'AT 400' AGL' WHEN THE ENGINE NOISE SUDDENLY 'DIED OFF' & THEN THEY HEARD A LOUD 'POP.'  THEY SAW PARTS FALLING OFF THE HELICOPTER AS IT FELL. AN EXAM OF THE WRECKAGE REVEALED A MAIN ROTOR BLADE ENTERED THE LEFT SIDE OF THE COCKPIT.  NO PREIMPACT SYSTEM MALFUNCTION WAS FOUND.  TOXICOLOGY TESTS SHOWED A TRACE OF MARIJUANA METABOLITE IN THE INSTRUCTOR'S URINE, BUT A TOXICOLOGIST CONCLUDED THERE WAS NO 'CURRENT INFLUENCE' OF THE DRUG. A TRACE OF COCAINE METABOLITE WAS DETECTED IN THE STUDENT'S URINE.  THE SAFETY BOARD FOUND THAT THERE WAS INSUFFICIENT EVIDENCE TO CONCLUDE THAT DRUGS HAD AFFECTED EITHER PILOT'S ABILITY TO OPERATE THE AIRCRAFT.

## Aircraft

- Registration: [N8475A](https://openairdocs.org/deregistered/N8475A-2013-06-07), registration cancelled 2013-06-07, S/N 0389, built 1984 (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: 0389
- Airframe hours: 2334
- Engines: LYCOMING O-320-B2C 160 horsepower reciprocating
- Damage: Destroyed
- Flight: Instructional, Part 91
- Operator: Helicopter Adventures, Inc.
- Registered owner: Helicopter Adventures, Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, October 12, 1987, 83 hours before
- Departed: CCR, CONCORD, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; commercial, flight instructor, private; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: right; toxicology performed; flight hours: 772 total, 456 in this make and model, 688 as pilot in command, 189 in the last 90 days, 73 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 60° at 6 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 48 °F
- Altimeter: 30.00 inHg
- Observed at: CCR, 8 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 19871103061769A](https://openairdocs.org/incident/19871103061769A), Nov 3, 1987: Robsin R22ALPHA, Moraga, CA, Destroyed, 2 fatal. Main rotor blade struck the cockpit and shattered inflight during possible engine out practice and rotor RPM decay.

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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