Maintenance Airframe; Maintenance Powerplant
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; Manuals; Procedure
During C-check on Aircraft X; Job Card# 731-XXX-XX-XX was performed. This Job Card requires the removal and reinstallation of both radio altimeter transceivers. During a normal C-Check the CAT III upgrade paperwork is automatically attached to the hangar work package to cover any Cat III items disturbed during the check. This zonal inspection did not have the CAT III paperwork attached to the package and I failed to notice the missing task card. The aircraft was then turned over to day shift who were unaware of the need for an upgrade and the aircraft left without a CAT III upgrade being accomplished. While working a phase check the following night I noticed that the aircraft also did not have a CAT III upgrade task card attached which reminded me of the aircraft from the previous night and caused me to look into the issue. This is where I realized the mistake and I reported to my supervisor. Supervisor from Maintenance Control was contacted and we were told the aircraft now parked would be downgraded by the flight crew and flown to ZZZ where it could be upgraded.Preventative Measures: The majority of checks done in the C-check environment automatically have CAT III upgrade paperwork attached. Some -800 Zonal and Phase checks do not have these task cards automatically attached to the package. Due to this in the C-check environment we are accustomed to the CAT III being automatic and when it was not in this case I missed it. I believe the best option would be for this task card to be automatically issued for any aircraft in the C-check environment or anytime a c-check; phase check; or zonal check is issued in any environment.
Technician reported missing a required CAT III upgrade after maintenance actions and the aircraft departed on a scheduled flight.