De Havilland DHC-8 N801WP

Summary

On 16 December 1996 at about 07:09 local time, a De Havilland DHC-8 registered N801WP, operated by Aloha Islandair Inc., was involved in an accident near Honolulu, Hawaii, United States. 13 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

16 December 1996 at 07:09

Classification

Accident

Location

Honolulu, Hawaii, United States

Nearest airport

Honolulu International (HNL)

Coordinates

21.3394, -157.9399

Aircraft

De Havilland DHC-8

Registration

N801WP

Category

Airplane

Engines

2

Operator

Aloha Islandair Inc.

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Lanai → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Night/Bright

NTSB number

LAX97FA069

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.