# NTSB LAX93LA044: Hughes 369D, N220AL, Carlsbad, CA, November 16, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: November 16, 1992, 06:34 local (14:34 UTC)
- Place: Carlsbad, CA
- Coordinates: 33.130817, -117.29953 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.1308&lon=-117.2995&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report October 29, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27868
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA044
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27868/pdf
- Page: https://openairdocs.org/ntsb/LAX93LA044

## Probable cause

FAILURE OF THE OVERRUNNING CLUTCH ASSEMBLY BEARING FOR UNDETERMINED REASONS.

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - rotor drive system,freewheeling sprag unit - failure,total (cause)
  - rotor drive system,freewheeling sprag unit - undetermined (cause)
  - rotor drive system,freewheeling sprag unit - overtemperature
- Forced landing, landing - flare/touchdown
  - autorotation - performed, pilot in command
- Hard landing, landing - flare/touchdown

## Analysis

DURING FLIGHT THE AIRCRAFT BEGAN TO VIBRATE SEVERELY, AND THEN THERE WAS A LOUD BANG. THE AIRCRAFT BEGAN TO DESCEND WITH SMOKE IN THE CABIN, AND THE ENGINE OUT LIGHT AND HORN WAS ACTIVATED. DURING LANDING, THE HELICOPTER SETTLED INTO THE DIRT, ROCKED FORWARD, THEN AFT. ACCORDING TO THE PILOT, THE MAIN ROTOR BLADES STRUCK THE TAIL BOOM DUE TO LOW ROTOR RPM. EXAMINATION REVEALED THAT AN OVERRUNNING CLUTCH BEARING HAD FAILED. A METALLURGICAL EXAMINATION COULD NOT DETERMINE THE CAUSE OF THE FAILURE BECAUSE OF THE EXTENT OF DAMAGE. THE BEARING ASSEMBLY & INNER RACE (SHAFT) WAS EXPOSED TO TEMPERATURES GREATER THAN 1500 DEG F. THE OVERRUNNING CLUTCH WAS REPORTEDLY LUBRICATED 7 HRS PRIOR TO THE ACCIDENT, AT THE LAST 100-HR INSPECTION. THE INSPECTION IS ALSO CONSIDERED A 300-HR INSPECTION; ACCORDING TO MDHC AT THE 300-HR INSPECTION THE BEARING IS TO BE REMOVED, CLEANED, INSPECTED AND REPACKED.

## Aircraft

- Registration: [N220AL](https://openairdocs.org/deregistered/N220AL-2013-07-11), registration cancelled 2013-07-11, S/N 1090606D, built 1979 (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: 1090606D
- Engines: ALLISON 250-C20B 320 horsepower turbo shaft
- Damage: Substantial damage
- Fire: In-Flight
- Flight: Part 91
- Operator: Haverfield Corporation
- Registered owner: Haverfield Corp
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, September 12, 1992, 13 hours before
- Departed: MYF, SAN DIEGO, CA
- Destination: NONE, PALOMAR, CA
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; commercial; instrument ratings: helicopter; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 5,805 total, 4,430 in this make and model

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point -0 °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 19921116046859A](https://openairdocs.org/incident/19921116046859A), Nov 16, 1992: Hughes 369D, Carlsbad, CA, Substantial damage. Smoke in cockpit, loud bang, engine quit. Autorotated. Chopped tail landing. Overrunning clutch bearing failed.

## Other investigations on N220AL (1)

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.

- [NTSB LAX03LA017](https://openairdocs.org/ntsb/LAX03LA017), Oct 29, 2002: Hughes 369D (N220AL), Kaaawa, Oahu, HI, destroyed. Probable cause: Dynamic rollover during an attempted takeoff, due to the combined effects of the soft sloping terrain and the pilot's failure to redistribute the passengers to a more favorable lateral CG condition.

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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