# NTSB LAX92FA267: Robinson R22, N83858, Richmond, CA, June 29, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 29, 1992, 12:42 local (19:42 UTC)
- Place: Richmond, CA
- Location: 37.9523° N, 122.3606° W: Placed by OpenAirDocs: center of Richmond, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=37.9523&lon=-122.3606&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report April 2, 1996
- Report: Approved by Office Director
- Safety recommendations: Yes
- NTSB case key (mKey): 27438
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92FA267
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27438/pdf
- Page: https://openairdocs.org/ntsb/LAX92FA267

## Probable cause

A DIVERGENCE OF THE MAIN ROTOR FROM ITS NORMAL PLANE OF ROTATION FOR AN UNDETERMINED REASON(S) WHICH RESULTED IN ROTOR CONTACT TO THE TAILBOOM.

## Sequence of events

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

- Ditching, cruise
  - rotor system - undetermined (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE STUDENT HAD RECORDED HER PRIMARY FLIGHT LESSON ON A TAPE RECORDER. AFTER REACHING THE PRACTICE AREA, THE CFI INSTRUCTED THE STUDENT TO TURN 180 DEG LEFT. THE STUDENT COMPLIED AND PERFORMED A SHALLOW BANK TURN. SECONDS LATER, WHILE CRUISING AT 2,200 FT, THE CFI BEGAN TALKING. IN MIDSENTENCE AN UNDETERMINED EVENT OCCURRED WHICH INTERRUPTED HIS SPEECH. A WIND-LIKE BACKGROUND NOISE STARTED, AND THE STUDENT EXCLAIMED 'HELP.' RADAR DATA CONFIRMED WITNESS REPORTS THAT THE TAIL BOOM AND M/R HAD SEPARATED IN LEVEL FLT. EXAM OF THE WRECKAGE INDICATED MAST BUMPING HAD OCCURRED, A M/R BLADE CRUSHED THE LEFT SIDE OF THE INBOARD TAIL CONE, AND THE ENTIRE MAST WITH ATTACHED M/R BLADES BROKE OUT OF THE TOP OF THE TRANSMISSION. THE OUTBOARD TAIL BOOM AND ROTOR ASSEMBLY HAVE NOT BEEN FOUND. EVIDENCE OF A MAIN ROTOR BLADE DIVERGENCE WAS FOUND. SPECTRUM ANALYSIS OF THE TAPE REVEALED NO ANOMALIES UNTIL THE CFI'S VOICE WAS TERMINATED. WITHIN 2 SECONDS THE ROTOR SPEED APPEARED TO SIGNIFICANTLY OSCILLATE AND ABRUPTLY END.

## Aircraft

- Registration: [N83858](https://openairdocs.org/deregistered/N83858-1995-06-08), registration cancelled 1995-06-08, S/N 0337 (OpenAirDocs)
- Reported make and model: ROBINSON R22
- Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs)
- Category: Helicopter
- Serial number: 0337
- Airframe hours: 4021
- Engines: LYCOMING O-320-B2C 160 horsepower reciprocating
- Damage: Destroyed
- Flight: Instructional, Part 91
- Operator: Sierra Academy Of Aeronautics
- Registered owner: Skyline Helicopters, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 26, 1992, 12 hours before
- Departed: OAK, OAKLAND, CA
- Destination: OAK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; flight instructor, commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 2,200 total, 2,000 in this make and model, 2,000 as pilot in command, 70 in the last 90 days, 14 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 11 knots
- Visibility: 15 statute miles
- Lowest ceiling: 12,000 ft broken
- Temperature: 66 °F, dew point 55 °F
- Altimeter: 29.00 inHg
- Observed at: NGZ, 13 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 19920629022239A](https://openairdocs.org/incident/19920629022239A), Jun 29, 1992: Robsin R22, Richmond, CA, Destroyed, 2 fatal. Tailboom was struck by main rotors,impact severed tail rotor assembly. Crashed in bay. Cause rotor strike unknown.

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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