# NTSB LAX92FA137: Robinson R22, N8413Q, Maricopa, AZ, March 4, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: March 4, 1992, 15:35 local (22:35 UTC)
- Place: Maricopa, AZ
- Location: 33.0581° N, 112.0476° W: Placed by OpenAirDocs: center of Maricopa, AZ, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=33.0581&lon=-112.0476&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report December 9, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27410
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92FA137
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27410/pdf
- Page: https://openairdocs.org/ntsb/LAX92FA137

## Probable cause

DESTRUCTIVE MAST BUMPING FOR AN UNDETERMINED REASON(S).

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise
  - reason for occurrence undetermined (cause)
  - misc rotorcraft,tail cone - separation
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE WRECKAGE WAS LOCATED ON FLAT DESERT TERRAIN ALONG A DIRECT COURSE LINE BETWEEN THE DEPARTURE & DESTINATION AIRPORTS. THE TAIL BOOM HAD SEPARATED IN FLIGHT. DAMAGE WAS CONSISTENT WITH A LOW 'G' EVENT RESULTING IN A RAPID RIGHT ROLL & SUBSEQUENT MAIN ROTOR BLADE STRIKE ON THE LEFT SIDE OF THE CABIN. THE DESIGN STRENGTH OF THE TAIL CONE'S ATTACHMENT POINTS WAS EXCEEDED. ACCORDING TO THE MANUFACTURER'S PAPER ON LOW 'G' MAST BUMPING, BOTH LATERAL CONTROL AND DAMPING IN ROLL ARE PROPORTIONAL TO G-LOAD; IN A TWO G PULLUP THEY BOTH DOUBLE, AND IN A ZERO G PUSHOVER THEY BOTH GO TO ZERO. WHEN THEY ARE ZERO, THE PILOT HAS NO LATERAL CONTROL, AND THE HELICOPTER HAS NO DAMPING IN ROLL. THE PILOT WAS REPORTEDLY KEENLY AWARE THAT ONE SHOULD NOT PLACE THE R22 INTO A NEGATIVE 'G' SITUATION, OR EVEN A LOW 'G' SITUATION, AND WAS VERY KNOWLEDGEABLE OF THE R22'S STRUCTURE AND SYSTEMS.

## Aircraft

- Registration: [N8413Q](https://openairdocs.org/deregistered/N8413Q-2000-07-14), registration cancelled 2000-07-14, S/N 0354 (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: 0354
- Airframe hours: 2128
- Engines: LYCOMING O-320-B2C 160 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Wesley F. Morris
- Registered owner: Wesley F. Morris
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 1, 1991, 48 hours before
- Destination: P19, CHANDLER, AZ

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 59; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: right; toxicology performed; flight hours: 31,000 total, 300 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 225° at 9 knots, gusting 20
- Lowest ceiling: 4,000 ft broken
- Temperature: 66 °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 19920304005279A](https://openairdocs.org/incident/19920304005279A), Mar 4, 1992: Robsin R22, Maricopa, AZ, Destroyed, 1 fatal. Indicates flight encountered turbulence. Caused roll low g damping mast bumping and boom strike. Inflight breakup.

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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