What was found
ITO - FLT 121 - CARGO SMOKE FIRE CAME ON FROM FORWARD CARGO COMPARTMENT. BOTTLE ONE DISCHARGED INDICATION CONTINUED HAD TO DISCHARGE NR 2 BOTTLE. PERFORMED BITE CHECK OF FORWARD CARGO PIT SMOKE DET SYSTEM FOUND DETS 1 AND 2 SHOWED FAULT ON SYSTEM ''B'' AND DET NR 3 FAULT SYSTEM ''A''. REMOVED AND REPLACED DET''S 1, 2, 3. BITE CHECK OK. REMOVED AND REPLACED AFT CARGO FIRE EXTINGUISHER BOTTLE AND SQUIBS. (M)