A Pakistan Air Force trainer aircraft crashed on Monday, killing both pilots onboard, the army said.It said that the aircraft was on a routine “training sortie” when it crashed near Mardan in the Khyber Pakhtunkhwa province.Both pilots, Flight Lieutenant Muhammad Qasim Abdullah (Pakistan Air Force) and Lieutenant Taha Abbasi (Pakistan Navy), were killed in the crash.A board of inquiry has been constituted by Air Headquarters to ascertain the cause of the accident.Field Marshal Asim Munir, services chiefs of Pakistan and all ranks of the Pakistan Armed Forces expressed grief over the loss of lives and extended heartfelt condolences to the bereaved families, it said.