# NTSB LAX87FA112: Hughes 369D, N1102U, Honolulu, HI, February 9, 1987

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: February 8, 1987, 15:30 local (Feb 9, 1987, 01:30 UTC)
- Place: Honolulu, HI
- Coordinates: 21.270719, -157.820434 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=21.2707&lon=-157.8204&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal, 2 serious, 2 minor
- Status: Completed, report February 20, 1989
- Report: Approved by Office Director
- Safety recommendations: Yes
- ADs cited in the narratives: AD 77-15-09, AD 81-10-08 (OpenAirDocs)
- NTSB case key (mKey): 25378
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX87FA112
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25378/pdf
- Page: https://openairdocs.org/ntsb/LAX87FA112

## Sequence of events

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

- Airframe/component/system failure/malfunction, takeoff - initial climb
  - rotor system,main rotor hub - corroded (cause)
  - maintenance,service of aircraft/equipment - inadequate, company maintenance personnel (contributing factor)
  - rotor system,main rotor hub - fatigue (cause)
  - maintenance,inspection - improper, company maintenance personnel (cause)
  - maintenance,recordkeeping - inadequate (contributing factor)
  - maintenance,service bulletin/letter - not followed, company maintenance personnel (contributing factor)
  - rotor system,main rotor blade - separation (cause)
  - fuselage - vibration
  - misc rotorcraft,tail boom - overload
- Loss of control - in flight, takeoff - initial climb
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - water,rough

## Analysis

DRG TKOF CLB, A LOUD NOISE OCCURRED AS 1 OF 5 MAIN ROTORS (MRB'S) & THE TAIL BOOM SEPD FM THE HELICOPTER (HEL). THE HEL THEN CRASHED & HIT A SUBMERGED REEF APRX 200' FM THE HELIPORT. AN EXAM OF THE FAILED MRB SHOWED ITS RETENTION STRAP ASSY(RSA), PN 369D21210-501, FAILED FM FATIGUE IN AN AREA OF CORROSION; 11 OF THE MRB'S 16 STRAP LAMINATES HAD PREEXISTING CRACKS. CORROSION WAS FND ON 78 OF 80 LAMINATES. THE MAINT HNDBK REQD THE RSA'S BE INSPECTED AT 25, 100 & 600 HR INTER- VALS. SVC INFO NOTICE (SIN) DN-77.1 RDMDD A 300 HR INSPN IF ANY CRACK OR LAMINATE FAILURE WAS FND DRG A 100 HR INSPN. AD'S 77-15-09R1 & 81-10-08 REQD INSPN W/I (BUT NOT OUTBRD OF) THE PITCH HOUSING. DRG 100 HR/AD INSPNS AFTER 1768 & 1839 HRS OF OPN, UP TO 3 CRACKS WERE FND IN LAMINATE LEGS, BUT THEIR LCTNS WERE NOT DOCUMENTED FOR LTR INSPN. HOWEVER, DRG 2 SUBSEQUENT 100 HR INSPNS BY ANOTHER MECH, NO CRACKED LAMINATES WERE NOTED. THE HEL HAD 2135 HRS OF OPN WHEN THE ACDNT OCCURRED. SVC INFO LTR DL-54 RCMDD A TRI-FLOW WASH PROC AFTER THE LAST FLT OF EACH DAY WHEN OPNG IN A MARINE ENVIRONMENT

## Aircraft

- Registration: [N1102U](https://openairdocs.org/deregistered/N1102U-1991-06-18), registration cancelled 1991-06-18, S/N 100820D (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)
- Category: Helicopter
- Serial number: 100820D
- Airframe hours: 2135
- Engines: Allison 250-C20B 375 horsepower turbo shaft
- Damage: Destroyed
- Flight: Part 91
- Registered owner: Royal Helicopter Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, January 13, 1987, 94 hours before
- Flight plan: Company VFR
- Airport: Z06, Ala Wai Heliport

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; commercial, private; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 8,518 total, 4,078 in this make and model, 7,950 as pilot in command, 134 in the last 90 days, 36 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 8 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 64 °F
- Altimeter: 29.00 inHg
- Observed at: HNL, 6 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 19870208050329A](https://openairdocs.org/incident/19870208050329A), Feb 8, 1987: Hughes 369D, Honolulu, HI, Destroyed, 1 fatal. Main rotor blade retention flaps failed due to corrosion causing delamination. Crashed on ocean reef.

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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