A DHC8-200 ACFT LEFT ENGINE FWD JET PIPE INSULATION BLANKET NOT INSTALLED DURING C-CHECK.

Narrative

L-HAND ENG FORWARD JET PIPE INSULATION BLANKET NOT INSTALLED DURING C-CHK. DURING ACFT A-CHK; A MECH NOTICED THE INSULATION BLANKETS WERE MISSING ON THE #1 ENG FORWARD JET PIPE. INVESTIGATION REVEALED THAT ALL STEPS FOR INSTALLATION OF THE JET PIPE AND SHROUDS WERE ACCOMPLISHED; EXCEPT A WARNING WAS OVERLOOKED TO MAKE SURE THE INSULATION BLANKETS WERE PROPERLY INSTALLED PRIOR TO INSTALLATION OF THE FORWARD JET PIPE. THE JET PIPE WAS REPLACED DURING THE (PREVIOUS) C-CHK AND THE REPLACEMENT (COMPONENT) DID NOT COME AS AN ASSEMBLY; IT CAME WITHOUT BLANKETS. A MAINT MANUAL 'WARNING' WAS MISSED; PERHAPS THE NEXT INSTALLATION STEP SHOULD HAVE REPEATED MOST OF THE WARNING. REMOVED AND REPLACED FORWARD #1 ENG JET PIPE ASSEMBLY; WHICH INCLUDES THE INSULATION BLANKET. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE JET PIPE IS ATTACHED TO THE ENGINE AFT CASE WITH A SPLIT FLANGE TYPE CLAMP ASSEMBLY. THE REPLACEMENT SHROUD AROUND THE JET PIPE NORMALLY COMES WITH INSULATION BLANKETS ATTACHED. THESE BLANKETS ARE SECURED WITH SAFETY WIRE TO THE SHROUD. HOWEVER; THIS SHROUD UNIT DID NOT COME WITH INSULATION INSTALLED. THIS ACFT FLEW APPROX FOR A WEEK BEFORE LINE INSPECTION NOTICED THE BLANKETS WERE MISSING. WHEN THE SHROUD WAS REPLACED; THE MAINT WARNING NOTICE WAS OVERLOOKED (NOT RECOGNIZED) AS PART OF THE INSTALLATION SIGN-OFFS ON THE WORK CARD.