The continuing rocket fire and debris on the runways at Tan Son Nhut caused General Homer D. Smith, the U.S. defense attaché in Saigon, to advise Ambassador Martin that the runways were unfit for use and that the emergency evacuation of Saigon would need to be completed by helicopter. Originally, Ambassador Martin had intended to effect the evacuation by use of fixed-wing aircraft from the base. This plan was altered at a critical time when a South Vietnamese pilot decided to defect, and jettisoned his ordnance along the only runways still in use (which had not yet been destroyed by shelling).