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Aloha IslandAir de Havilland DHC-8 accident

15 Dec 1996 · Honolulu, HI, United States

de Havilland DHC-8 · Accident: airframe, component or system failure on approach

From Lanai Airport (LNY) to Daniel K. Inouye International Airport (HNL)

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Event

NTSB case
LAX97FA069
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
Airline
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

de Havilland DHC-8

Aircraft type
de Havilland DHC-8
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N801WP
Onboard fatalities
Unknown
Route
From Lanai Airport (LNY), LANAI, HITo Daniel K. Inouye International Airport (HNL)
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 121: Air Carrier
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Approach
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Airframe, component or system failure
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Company maintenance personnel › Maintenance, service of aircraft/equipment, inadequate
  • Fluid, hydraulic › Low level
  • Fluid, hydraulic › Pressure too low
  • Hydraulic system, fitting › Leak
  • Landing gear, emergency extension assembly › Binding(mechanical)
  • Landing gear, emergency extension assembly › Contamination
  • Landing gear, emergency extension assembly › Worn

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

Hydraulic fluid was leaking from a deteriorated O-ring in the landing gear selector solenoid valve, rendering the normal landing gear extension system inoperative. The crew actuated the alternate gear extension system and was unable to extend the right main landing gear. The first officer pulled the main landing gear alternate extension cable until it stopped and the right main landing gear uplock actuator did not release. On advice from company maintenance, after completing the alternate gear extension procedure, the crew retracted the nose gear and the left main gear using the normal system and then attempted another normal extension. Only the left main landing gear extended. The airplane's number 2 hydraulic system was depleted with 1.5 quarts of fluid remaining. The crew attempted another retraction to raise the left main landing gear without success. The captain then landed the airplane with only the left main landing gear extended. Examination of the alternate gear system revealed the main gear extension cable would bind after the left main landing gear uplock actuator would release. Subsequent testing of the system while the airplane was on jack stands reduced the binding, but in all tests the left main landing gear uplock actuator would release before the right uplock actuator. Examination of the main landing gear alternate extension cable revealed the plastic coating was missing in two places adjacent to a pulley. The right main landing gear wheel well was excessively dirty with areas of exfoliated white paint, exposing the underlying primer.

Probable cause

A failure of the normal landing gear extension system due to a hydraulic leak, and the failure of the airplane's emergency landing gear extension system due to inadequate servicing by company maintenance personnel. Factors were the emergency landing gear extension systems dirty and binding condition, a worn emergency landing gear extension cable, and the training simulator's lack of fidelity concerning the force required to operate the emergency gear extension T-handle.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX97FA069
Event ID
20001208X07185
Case number
LAX97FA069
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: local date, investigation status. Values present in the bulk record are kept.
  • The date is the local date; the NTSB stores the UTC date 1996-12-16.
  • API snapshot SHA-256: 8be83f1cffa56401b701ec73fddee8d4cff7083edf36d48ea8c5f1cd7f57e2e0; retrieved 2026-09-18T17:44:19.867Z.