8 fatalities

Crew Descended Below Minimum Altitude in IMC, Struck Mountain Near Mankayan (RP-C990)

Mankayan, PhilippinesFlight

On July 28, 1999, a Beechcraft 90 King Air (registration RP-C990) operated by Lepanto Consolidated Mining Company was involved in an aviation accident near Mankayan, Philippines in flight. 8 people were killed. Investigators recorded the probable cause as: Controlled flight into terrain after the crew descended below the minimum prescribed altitude in IMC conditions. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Source recordUpdated 2026-07-04Data APIEditorial standards

While descending to Mankayan Airport in poor weather, the crew descended below prescribed altitude in IMC, causing a controlled flight into terrain. All eight occupants were killed.

Accident

On a flight from Poro Point to Mankayan Airport, the aircraft encountered poor weather conditions with rain and limited visibility during descent. The crew requested the latest weather bulletin for Mankayan when the aircraft struck the slope of a mountain approximately 20 kilometers from the airport. All eight occupants were killed.

Details

The accident occurred while the aircraft was descending to Mankayan Airport. The weather at the time included rain and restricted visibility. The crew had just asked for the most recent weather information for their destination when the collision with the mountain took place.

Probable Cause

The official investigation determined the probable cause to be: Controlled flight into terrain after the crew descended below the minimum prescribed altitude in IMC conditions.

Frequently asked questions

What happened in the 28 Jul 1999 Beechcraft 90 King Air accident near Mankayan, Philippines?

While descending to Mankayan Airport in poor weather, the crew descended below prescribed altitude in IMC, causing a controlled flight into terrain. All eight occupants were killed.

Were there any fatalities in the 28 Jul 1999 Beechcraft 90 King Air accident?

The accident was fatal, resulting in 8 fatalities.

What aircraft was involved and where did it happen?

The accident on 28 Jul 1999 involved a Beechcraft 90 King Air, registration RP-C990, operated by Lepanto Consolidated Mining Company, at Mankayan, Philippines.

What was the probable cause of the accident?

Controlled flight into terrain after the crew descended below the minimum prescribed altitude in IMC conditions.