The Royal Thai Air Force (RTAF) is expected to take a month to investigate the cause of the fighter aircraft "Gripen" which crashed at the Hatyai Airport, Saturday.

RTAF Security Office director Vice Air Marshal Sorakit Mangsing said one month was needed to investigate numerous factors which could have caused the incident.

"Numerous factors must be studied, including the pilot's condition, the environment and others. It also has to take into account science and engineering. Preliminary investigations has not indicated the cause," he told reporters Sunday.

However, he said the aircraft was in a good condition before the flight on Saturday and had undergone careful inspection while the pilot was healthy.

Gloom descended on the Songkla Nakharin Hospital, Hatyai when the family claimed the remains of pilot Captain Dilokrit Patawee, 35. -- Bernama