A B737-300 HAD THE #1 ADC REPLACED AT A NON MAINT STATION. TECHNICIAN REPLACED COMPUTER AND TESTED PER THE MAINT MANUAL.

Narrative

FAA LETTER OF INVESTIGATION INDICATES THAT I FAILED TO RECEIVE AN RII SIGNOFF ON THE INSTALLATION OF THE ADC REMOVAL AND INSTALLATION. I WAS SENT BY MAINT CTL AND MY SUPVR TO ZZZ TO RECOVER ACFT X REQUIRING THE INSTALLATION OF THE #1 ADC. I WAS ADVISED IT ONLY REQUIRED A LAND VERIFY TEST. (ON-CALL) MAINT WAS ON THE SITE AND WAS GOING TO INSTALL IT BUT WAS UNABLE TO VERIFY THE CAT STATUS. WHEN I ARRIVED; THE PART WAS THERE AND (ON CALL) MAINT HAD LEFT. I HAD THE R&R PAPERWORK FROM THE MAINT MANUAL ALONG WITH THE TEST PAPERWORK AND PERFORMED R&R TEST. NOTIFIED MAINT CTL THAT I PERFORMED R&R AND TEST AND THE ACFT HAD PASSED. FAX THE PAPERWORK TO MAINT CTL FOR (COMPUTER SYS) ENTRY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ADC WAS REPLACED AT AN OFF-LINE NON MAINT STATION. THE INSPECTION THAT WAS NOT PERFORMED IS A GPM CHK OF THE ADC QUICK DISCONNECT STATIC AND PITOT FITTINGS FOR BEING INSTALLED. SINCE THE RPTR WAS WORKING THE JOB ALONE; NO ONE ELSE WAS AVAILABLE OR QUALIFIED TO CHK THE FITTINGS. THE PITOT AND STATIC SYS WAS CHKED PER THE MAINT MANUAL AND FOUND NOT LEAKING.