# NTSB LAX84FA405: Hughes 369D, N58369, Mesa, AZ, July 18, 1984

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 18, 1984, 11:57 local (18:57 UTC)
- Place: Mesa, AZ
- Coordinates: 33.429946, -111.709243 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.4299&lon=-111.7092&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 23979
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX84FA405
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23979/pdf
- Page: https://openairdocs.org/ntsb/LAX84FA405

## Sequence of events

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

- Airframe/component/system failure/malfunction, climb
  - rotor drive system,clutch assembly - undetermined (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - none suitable (contributing factor)
  - autorotation - not possible, pilot in command (contributing factor)
  - acft/equip,inadequate instrument display, manufacturer

## Analysis

THE HELICOPTER EXPERIENCED A MAIN ROTOR DRIVE SYSTEM DISCONNECT, AN UNCONTROLLED DESCENT & SUBSEQUENT INFLIGHT COLLISION WITH TERRAIN IN A HILLY DESERT AREA. THIS WAS THE THIRD & LAST IN A PLANNED SERIES OF MARKETING DEMO FLTS CONDUCTED FOR THREE USMC OFFICERS. DURING THE POST CRASH EXAMINATION OF OVER-RUNNING CLUTCH COMPONENTS REVEALED THAT THE CAGES & SPRAGS WERE BOUND UP IN THEIR NORMAL ENGAGED POSITIONS. TWO OF THE THREE DRAG STRIPS WERE OBSERVED TO HAVE ABRASION SIGNATURES ACROSS THEIR ENTIRE WIDTH OF .07 INCHES; THE ABRASION AREAS GENERALLY MATCHED THE GEOMETRY OF THE ADJACENT BALL BEARING RACE. EXAMINATION OF ENGINEERING DRAWINGS FOR THE CLUTCH REVEALED THAT FOR THE DRAG STRIP TO CONTACT THE ADJACENT BEARING RACE, THE CLUTCH WOULD HAVE TO PROTRUDE OUT OF ITS NORMAL RELATIVE POSITION BY ABOUT .20 INCHES. HEAVY OXIDATION OBSCURED THE POTENTIAL RELATIVE RUNNING POSITION MARKINGS BETWEEN THE INNER & OUTER RACES.

## Aircraft

- Registration: [N58369](https://openairdocs.org/deregistered/N58369-2005-12-14), registration cancelled 2005-12-14, S/N 1200848D, built 1980 (OpenAirDocs)
- Reported make and model: HUGHES 369D
- Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs)
- Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1200848D
- Airframe hours: 469
- Engines: ALLISON 250-C20B 420 horsepower turbo shaft
- Damage: Destroyed
- Fire: On-Ground
- Flight: Part 91
- Registered owner: Hughes Helicopters, Inc.
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, December 25, 1984, 10 hours before
- Departed: FFZ, MESA, AZ
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; toxicology performed; flight hours: 4,004 total, 109 in this make and model, 3,802 as pilot in command, 72 in the last 90 days, 30 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 5 knots
- Visibility: 25 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 99 °F
- Altimeter: 30.00 inHg
- Observed at: FFZ, 5 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 19840718075629A](https://openairdocs.org/incident/19840718075629A), Jul 18, 1984: Hughes 369D, Mesa, AZ, Destroyed. Crashed during low level maneuvers on demonstration flight. Main rotor drive disconnected.

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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