Two Mechanics who were assigned slide changes for doors 1-left and 1-right; report they never changed a slide on an A320; did not have any training and were unfamiliar with company policies regarding management sign-offs. Slide safety pins were found installed by downline maintenance station.

Narrative

Mr. X and I were assigned slide changes for doors 1L and 1R of Aircraft X. Neither he nor I had ever done a slide change on an Airbus; have had no training; and were unfamiliar with company policies regarding Management signoffs. Mr. Y was the Foreman on shift; and I believe Mr. Z to be the Operations Manager. Mr. Y has been on the job for about 1 month and is also unfamiliar with company policy. Mr. X and I followed the Maintenance Manual and installed both slides; called Inspection and signed off the job. At no time did I see any streamer to remove pins on either slide. If I had; I would have done so. I cannot believe that neither Mr. X nor the Inspector missed these streamers either. The bustles were installed after the inspection and Mr. X and I were very happy with the installation of the slides. We were on a tight schedule to get the plane back in service. Callback conversation with Reporter revealed the following information: Reporter stated that none of the four Mechanics involved; which include himself and an Inspector; could believe they all missed the safety pins on both cabin door slides. The downline station reported they found both safety pins installed with the colored streamers hanging down along the door. Reporter stated he believes the A320 had departed on a non-revenue position flight to another station that also had maintenance personnel. Reporter stated a specific job card for slide changes is issued whenever slide changes are scheduled. Because the slides he was involved with were changed as a result of non-routine write-ups; their procedures did not auto-generate that specific job card. They had worked from the Maintenance Manual. Even his Supervisor; who had been on the job for only a month; did not know of the special procedures that management was responsible for; and required to sign for; whenever a slide change occurred.