A Line Mechanic describes his efforts to locate information that would show a Multi-Mode Receiver (MMR) he installed on an A300 aircraft in March 2011 was 'Effective' for that aircraft; at that time.
Synopsis
A Line Mechanic describes his efforts to locate information that would show a Multi-Mode Receiver (MMR) he installed on an A300 aircraft in March 2011 was 'Effective' for that aircraft; at that time.
Narrative
Company A300 aircraft; Pilot write-up was GPS-1 fault on descent. [I] troubleshot problem to the Multi-Mode Receiver (MMR). The MMR Manufacturer Part Number (P/N) removed was 822-1152-122. The P/N installed was 822-1152-002. The problem was just brought to my attention. The A300 Illustrated Parts Catalog (IPC) shows at this time that P/N 822-1152-002 is not effective for this aircraft. The A300 aircraft has been flying since March 2011 with no problems noted in the system. In doing research on the part in question; the two MMR parts are interchangeable as per Boeing B767 IPC; but not shown to be in the A300 IPC with the current revision. The cause of the problem may be as simple as the [MMR unit] -002; was removed from the A300 IPC in a Manual Revision (M/R) between March 2011 and January 2012. But getting access to the previous revision is proving to be difficult. The [MMR unit] 822-1152-002 was removed from the A300 aircraft in January 2012 and replaced by P/N 822-1152-122; when part in question was discovered. If a suitable substitute part is installed on an aircraft the Revision Number/Date [should] be listed on Parts Tag so that if this issue arises again; there is additional reference to the part in question. If the cause of the problem was not a Manual Revision issue; I will take steps needed to ensure the correct part is being installed on any aircraft as I have done in the past 25-years without an incident. Please note if the past Revisions are found and [MMR] Part Number [-002] is on there; this will be a non-issue.
NASA callback
Reporter stated he was informed about a possible incorrect part installation when a Stores/Parts employee noticed he could not order a new -002 MMR unit to replace the one he had installed from Stores. Reporter than decided to do some back tracking research and with help from one of his Supervisors; he located two other Illustrated Parts Catalog (IPC) Manual Revisions from Engineering that had been issued after he had installed the Multi-Mode Receiver (MMR) unit -002 in the A300 aircraft in March 2011. The dates of the revisions clearly showed the MMR-002 unit he installed was 'Effective' for the A300 aircraft at that time. Reporter stated he was later informed that upgrade modifications; possibly GPS upgrades; to Multi-Mode Receivers -121 and -122 by the Manufacturer; Collins Avionics; are the units they now install in their A300s. But; there are A300s still flying around with -002 MMRs; even though they are currently not considered 'Effective' in their revised A300 IPC Manual.Reporter also stated that now; whenever they are installing a part that is considered a 'suitable substitute' part; they must attach a copy of the Illustrated Parts Catalog (IPC) information to the log page they are signing-off. MMR units -002; -121 and -122 are still 'Effective' for installation on Boeing B767 aircraft.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.