PHILIPPINE AIRLINES, INC., PETITIONER, VS. ENRIQUE LIGAN, EDUARDO MAGDARAOG, JOLITO OLIVEROS, RICHARD GONCER, EMELITO SOCO, VIRGILIO P. CAMPOS, JR., LORENZO BUTANAS, RAMEL BERNARDES, NELSON M. DULCE, CLEMENTE R. LUMAYNO, ARTHUR M. CAPIN, ALLAN BENTUZAL, AND JEFFREY LLENES, RESPONDENTS