Investigation Summary
The flight departed Kahului at 18:25 HST for a short 25-minute hop to Molokai. Although cleared for 1,000 feet, the crew descended to 500 feet shortly after departure, violating both federal regulations and company night operating procedures. As the aircraft approached the eastern end of Molokai, it encountered orographic clouds generated by trade winds, which were not mentioned in the weather forecast. The investigation determined that there were no navigational lights on the eastern end of Molokai; consequently, the island and the clouds would have been detectable only as an 'occlusion on a dim horizon.' Investigators believe the captain mistook the phosphorescent surf breaking at Cape Halawa for Lamaloa Head. Based on this misidentification, he initiated a turn to the west to parallel the coast, unknowingly flying directly into the north side of Halawa Valley. The aircraft struck a 27-degree slope at approximately 600 feet elevation. The NTSB found that the captain had a history of unprofessional behavior and poor judgment, including a previous license suspension, which the airline had failed to discover during hiring. Furthermore, the airline's training program was found deficient in Crew Resource Management (CRM) and instrument proficiency.
Final Conclusions
The NTSB determined the probable cause was the captain's decision to continue VFR flight at night into IMC, which obscured rising terrain. Contributing factors included inadequate supervision of personnel and training by Aloha IslandAir management, and insufficient oversight by the FAA during the airline's rapid growth. The board also noted that the lack of a Ground Proximity Warning System (GPWS) on the aircraft and an incomplete weather forecast regarding orographic clouds contributed to the disaster.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
30 years old; started as a ramp agent at Princeville Airways; recently completed two weeks of Boeing 737 ground school. Involved in a 1986 ground loop incident in a Piper PA-28 Cherokee in Juneau, Alaska, caused by malfunctioning brakes.
First Officer
27 years old; started as a ramp agent in July 1988; hired as a First Officer in August 1989.
Systems & Failure Modes
Ground Proximity Warning System (GPWS)
A system designed to alert pilots if their aircraft is in immediate danger of flying into the ground. The NTSB calculated that a GPWS would have provided a 'TOO LOW TERRAIN' warning approximately 0.7 seconds after crossing the coastline, which was 7 seconds prior to impact.
Minimum Safe Altitude Warning (MSAW)
A ground-based radar system function that alerts controllers if an aircraft descends below a safe altitude. Because the crew switched to a VFR transponder code and left the ATC frequency, they did not receive potential MSAW alerts.
Interesting Facts
- 01The aircraft was not equipped with a Ground Proximity Warning System (GPWS), which was not required for Part 135 operators at the time.
- 02The captain had been training to fly Boeing 737s for the previous two weeks, leading to potential fatigue.
- 03The 18 passengers included members of the Molokai High School girls' and boys' volleyball teams and their athletic director.
- 04The captain's commercial pilot license had been suspended for six months in 1985 for unauthorized air taxi flights and reckless operation.
- 05The weather forecast failed to predict the 500-foot ceiling caused by orographic clouds on the windward side of Molokai.
Safety Actions & Advisories
GPWS Mandate
The NTSB reiterated recommendations to require GPWS on all multi-engine, turbine-powered fixed-wing airplanes certificated to carry 10 or more passengers (14 CFR 135.153).
Pilot Background Checks
The NTSB urged the FAA to require commercial operators to conduct substantive background checks of pilot applicants, including FAA enforcement history and previous employer performance records.
Weather Reporting Improvements
The NTSB recommended that the National Weather Service include the possibility of orographic clouds in forecasts whenever conditions for their formation exist.
Known Controversies & Unanswered Questions
Dissenting Statement on Probable Cause
Reference ↗NTSB Board Member Jim Burnett filed a dissenting statement, arguing that the failure of the FAA to require a Ground Proximity Warning System (GPWS) for Part 135 aircraft should have been included as a contributing factor in the official statement of probable cause.