What was found
IMMEDIATELY AFTER TAKEOFF, NOTICED A MEDIUM PITCH AUDIBLE VIBRATION. INDICATION OF HIGH N1 VIBRATION ON NR 1 ENG & LOW OIL PRESS. REDUCED POWER ON NR 1 ENG & OIL PRESS INCREASED TO NORMAL RANGE MOMENTARILY THEN VARIED BETWEEN NORMAL & LOW YELLOW RANGE. LANDED IMMEDIATELY & SECURED NR 1 ENG BEFORE TAXING IN. THERE WERE NO ACCOMPANYING EIED, MINELCO, OR FADEC RELATED INDICATIONS. REMOVED AND REPLACED SIX EACH DAMAGED FAN BLADES P/N: 3050776-2, NSN. WORK DONE IAW LMM 72-70-02. COMPLIED WITH ENGINE RUN AND VIBRATION SURVEY PER CFE738 LMM 72-00-00. ALL CHECKS GOOD. REMOVED LT ENGINE OIL PRESSURE TRANSMITTER P/N: 3051103-1, S/N: 991533810003 AND INSTALLED A NEW CONDITION TRANSMITTER P/N: 3051103-2, S/N: 1316206700171. WORK DONE PER LMM 79-30-04. RAN LT ENGINE AND OPS AND LEAK CHECKS GOOD.