 He immediately joined GAP 2 in the field on an operation along the Pavie Track to relieve the garrison at Mường Pồn.The operation was a failure; GAP 2 was repeatedly ambushed along the Pavie Track and reached Muong Pon after the garrison had been overrun.The return to Dien Bien Phu was harassed by frequent Viet Minh ambushes and artillery fire.