Were there any fatalities in the 1986-07-23 Mitsubishi MU-300 Diamond accident?

The accident was fatal, resulting in 4 fatalities.

Training Flight Collides with Mount Kinpoku on Sado Island (JA8246)

Q: What aircraft was involved and where did it happen?

The accident on 1986-07-23 involved a Mitsubishi MU-300 Diamond, registration JA8246, operated by The Yomiuri Shimbun, at Mt Kinpoku (Sado Island), Japan.

On July 23, 1986, a Mitsubishi MU-300 Diamond (registration JA8246) operated by The Yomiuri Shimbun was involved in an aviation accident near Mt Kinpoku (Sado Island), Japan during landing or approach. 4 people were killed. Investigators recorded the probable cause as: Controlled flight into terrain after the crew initiated the descent under VFR mode in IMC conditions in preparation of an ILS approach to runway 10 at Niigata Airport. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781217261Data API Editorial standards

A training flight from Tokyo-Haneda to Niigata struck Mount Kinpoku on Sado Island during descent in poor weather, killing all four crew members. The aircraft was destroyed.

Accident Overview

A training flight departing from Tokyo-Haneda Airport, destined for Niigata Airport, ended in tragedy when the aircraft collided with the slope of Mount Kinpoku, located near the center of Sado Island. The accident occurred during the descent phase, approximately 67 kilometers northwest of the threshold of Runway 10 at Niigata Airport. The aircraft was destroyed, and all four crew members lost their lives.

Weather and Operational Conditions

The descent was conducted in limited visibility due to adverse weather conditions. The crew had initiated the descent under visual flight rules (VFR) mode, despite being in instrument meteorological conditions (IMC). This decision was made in preparation for an instrument landing system (ILS) approach to Runway 10 at Niigata Airport.

Accident Details

The aircraft struck the mountainous terrain of Mount Kinpoku while still at a significant distance from the airport. The impact point was consistent with controlled flight into terrain (CFIT), where an airworthy aircraft is inadvertently flown into terrain or water with no prior awareness of the impending collision by the crew.

Probable Cause

The official investigation determined that the accident was the consequence of a controlled flight into terrain after the crew initiated the descent under VFR mode in IMC conditions in preparation of an ILS approach to runway 10 at Niigata Airport.

Controlled flight into terrain

1986-07-23: Mitsubishi MU-300 Diamond (JA8246) — The Yomiuri Shimbun — Mt Kinpoku (Sado Island), Japan