The Philippine Air Force (PAF) has grounded its entire fleet of OV-10 Bronco bomber aircraft following a crash due to engine failure.

PAF spokesperson lieutenant colonel Migue Okol said that six other OV-10 bombers will be grounded until the investigation is completed.

The unarmed bomber plane was on a routine test flight when its right engine failed, leading to the crash at Edwin Andrews Air Base in Zamboanga, according to

The OV-10 bomber is a turboprop light attack and observation aircraft designed for counter-insurgency (COIN) combat, and visual reconnaissance missions.

The planes were used by the 3rd Air Division to support the Western Mindanao Command’s (Westmincom) operations in Payao, Zamboanga Sibugay, and Sulu air strikes.