11 fatalities

Scenic Air Tours Flight 21 Crash in Waipio Valley Canyon (N34AP)

Waipio Valley, United States of AmericaFlight

On June 11, 1989, a Beechcraft H18 (registration N34AP) operated by Scenic Air Tours was involved in an aviation accident near Waipio Valley, United States of America in flight. 11 people were killed. Investigators recorded the probable cause as: The pilot's improper in-flight planning/decision to maneuver with insufficient altitude over or in a canyon area. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 3 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-06-11Data APIEditorial standards
Aircraft registered N34AP
Aircraft registered N34AP. Photo: Peter M Garwood / CC BY-SA 4.0, via Wikimedia Commons

A Beech H18 on a sightseeing flight crashed in a canyon near a waterfall in Waipio Valley, Hawaii, killing all 11 occupants. The pilot had maneuvered below the rim, contrary to company policy, and no preimpact mechanical problems were found.

Accident Details

Scenic Air Tours flight 21, a Beech H18 registered as N34AP, was operating as an air taxi sightseeing flight from Hilo to Kahului, Hawaii. The pilot departed at approximately 1300 HST and proceeded northwest along the coastline at an altitude of about 2,000 feet. The aircraft subsequently crashed in a scenic canyon area near a waterfall in Waipio Valley, approximately 50 miles northeast of Hilo. Impact occurred at an elevation of about 2,800 feet, roughly 600 to 900 feet below the canyon rim. No preimpact mechanical problem of the aircraft or engines was found.

Pilot Maneuvers

A passenger on a previous sightseeing flight reported that the pilot had maneuvered below the rim of a canyon. Company officials stated that flying below canyon rims was against company policy; however, the operations manual did not contain any guidance or cautions regarding such operations.

Aftermath

All 11 occupants were killed in the accident.

Probable cause

The pilot's improper in-flight planning/decision to maneuver with insufficient altitude over or in a canyon area. Factors related to the accident were: the terrain conditions and Scenic Air Tour's lack of specific direction to its pilots concerning safety procedures for sightseeing flights.