A Philippine air force helicopter crashed while preparing to land in the southern Philippines Sunday, injuring all seven people on board, an army spokesman said. The Huey chopper went down in the village of Bangayan in Kitcharao town in the province of Agusan del Norte, Major Eugenio Osias was quoted as saying by DPA. Osias said the aircraft was on a mission to evacuate a wounded soldier and deliver additional provisions to troops in the area. The cause of the accident was still unknown. The pilot, co-pilot and five passengers were in stable condition, Osias said.