Narrative:

During cruise flight we had a fault light on ir number 2. We complied with the ECAM and referred to the FM and completed the additional steps. We did switch the ir to att mode and entered our heading per the FM but the ir seemed to remain completely inoperative. The mrm code for the malfunction was entered into ACARS. Approximately 55 miles out during descent ir number 3 faulted. This resulted in the loss of the a/T along with both autopilots and flight directors and the first officer's flight displays and put us into alternate law. I became the PF and the first officer completed the ECAM and referred to the FM. The ECAM kept repeating and was difficult to clear and step through. By this time we were with approach control and cleared direct to a fix on the ILS to intercept. Approach control advised us LLWAS was in effect with winds out the n-nw at 10-15 KTS and that there had been recent reports of west/south. We were less than 30 NM out and there were still more of the checklist to read through and also the approach/landing corrections for failures procedure to complete. Considering these factors and since I was hand flying on raw data and the first officer was very busy we decided it was prudent to declare an emergency and request delay vectors. The first officer completed the checklists; the landing procedure and landing distance calculations; and notified dispatch. The flight attendants and the passengers were briefed. I did not ask for cabin prep or request arff equipment. We completed an extended 270 degree right turn and landed uneventfully on the slightly longer runway. The airplane was in direct law for landing and flaps 3 per the FM. The wind was reported I think 350/11 with no recent west/south. The arff trucks were out and followed us to the gate. We briefed maintenance and the outbound flight crew. Had we been further out when the second ir failed we may not have declared an emergency. In that case we would have had plenty of time to do everything and this would have been more of a non-event. However this situation presented like it would have made a good traditional simulator training scenario happening so close to arrival. Over the years I have been advised that declaring an emergency helps buy time and reduce workload with the service ATC provides. We did not especially want to hold with raw data or be rushed in for landing. I also thought the risk of a pilot deviation was greater due to no autoflight at all and the workload as it was.

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Original NASA ASRS Text

Title: A320 flight crew experiences the loss of two IRU's. The first in cruise and the second an hour and a half later during descent. This results in Alternate Law flight controls and Direct Law when the gear is extended for landing. The time required to accomplish all checklists is long and the crew elects to declare an emergency to accomplish them.

Narrative: During cruise flight we had a fault light on IR Number 2. We complied with the ECAM and referred to the FM and completed the additional steps. We did switch the IR to ATT mode and entered our heading per the FM but the IR seemed to remain completely inoperative. The MRM code for the malfunction was entered into ACARS. Approximately 55 miles out during descent IR Number 3 faulted. This resulted in the loss of the A/T along with both autopilots and flight directors and the First Officer's flight displays and put us into alternate law. I became the PF and the First Officer completed the ECAM and referred to the FM. The ECAM kept repeating and was difficult to clear and step through. By this time we were with Approach Control and cleared direct to a fix on the ILS to intercept. Approach control advised us LLWAS was in effect with winds out the N-NW at 10-15 KTS and that there had been recent reports of W/S. We were less than 30 NM out and there were still more of the checklist to read through and also the Approach/Landing Corrections for Failures procedure to complete. Considering these factors and since I was hand flying on raw data and the First Officer was very busy we decided it was prudent to declare an emergency and request delay vectors. The First Officer completed the checklists; the landing procedure and landing distance calculations; and notified Dispatch. The flight attendants and the passengers were briefed. I did not ask for cabin prep or request ARFF equipment. We completed an extended 270 degree right turn and landed uneventfully on the slightly longer runway. The airplane was in direct law for landing and flaps 3 per the FM. The wind was reported I think 350/11 with no recent W/S. The ARFF trucks were out and followed us to the gate. We briefed Maintenance and the outbound flight crew. Had we been further out when the second IR failed we may not have declared an emergency. In that case we would have had plenty of time to do everything and this would have been more of a non-event. However this situation presented like it would have made a good traditional simulator training scenario happening so close to arrival. Over the years I have been advised that declaring an emergency helps buy time and reduce workload with the service ATC provides. We did not especially want to hold with raw data or be rushed in for landing. I also thought the risk of a pilot deviation was greater due to no autoflight at all and the workload as it was.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.