"MG-520s are currently grounded as per procedure until investigation is over and the cause is determined," Lt. Col. Miguel Okol, PAF spokesman, told ABS-CBN Zamboanga.
An MG-520 helicopter piloted by Maj. Rover Sobrino together with his student pilot Capt. Edwinparcia encountered an engine trouble during a training flight around 2 p.m. Wednesday.
Sobrino said that after they detected that the chopper was having an engine trouble, he and his student decided to land it to a vegetated area in Barangay Talisayan, Zamboanga City.
The 2 pilots survived the emergency landing.
Okol said the PAF has a total of 30 MG-520 attack helicopters. He said 11 of the choppers have been involved in "incidents," 7 of which are being recovered, repaired or programmed to be repaired.
He added that 3 of the attack helicopters have been "written off entirely."
Maj. Gen. Horacio Lino, 3rd Air Division commander, meanwhile, said the grounding of the attack helicopters might affect ongoing military operations in Mindanao.
Lino said the MG-520s are usually dispatched to reinforce troops engaged in clashes with armed groups in the south.