Date: 201403
Local time of day: 0001-0600
Location: TUS.Airport, AZ
Flight conditions: VMC
Light: Night
Aircraft: Airbus 318/319/320/321 Undifferentiated
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class C TUS
ATC / advisory: TRACON TUS
Aircraft component: GPWS
Component problem: Design
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Captain; Pilot Flying
Anomaly: No Specific Anomaly Occurred All Types
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Contributing factors: Procedure; Environment - Non Weather Related; Aircraft
Primary problem: Aircraft

Narrative: The Captain was the pilot flying; I (the First Officer) was the pilot not flying. We were cleared for the visual approach to Runway 11L in Tucson; Arizona. The Captain made a right downwind; then a right base; then intercepted the localizer for the visual approach (backed up by the ILS) to Runway 11L. After calling the field in sight and subsequently cleared for the visual approach; the Captain entered direct 'WASON' in the FMS and set 5;500 FT in the Altitude Window on the MCP; which I confirmed per the Approach Plate. As we were descending just outside of 'WASON' toward 5;500 FT and simultaneously intercepting the Localizer; we received a GPWS 'Terrain' 'Pull-Up'. The Captain immediately went TOGA and climbed over 1;000 FT. At this point; since we were still 8 or 9 miles from the runway and still in a normal position to continue the approach to a normal VFR landing (still with ILS backup); the Captain elected to continue the visual (ILS backup) approach to a normal landing and taxi-in. I believe the Captain flew all the correct altitudes; consistent with the ILS Runway 11L step-down altitudes listed on the Approach Plate. Further; what I believed triggered the GPWS was the 4565 FT obstacle located just outside of 'WASON' which we would've flown almost directly over during our controlled descent to 5;500 and 'dogleg' localizer intercept. Since the Enhanced GPWS is predictive in nature; I believe the software was projecting a 'continued' descent (i.e. below 5;500 FT) toward this database obstacle; even though we were subsequently going to 'level out' momentarily per the step-down altitude guidance on the Approach Plate. Therefore; GPWS issued the warning as a direct result of this 'descending projection'. Again; I believe the Captain complied with company SOP's and executed properly. The terrain outside of WASON (on the approach to Runway 11L) has been known to trigger GPWS; since the altitude clearances are so tight and the aircraft is normally descending for the approach. Enhanced GPWS is predictive and thus sometimes 'projects' continued descents on 'step-down' Approaches. Nonetheless; all GPWS Warnings must be obeyed and proper SOP's followed; and were followed in this event. I believe it would be helpful to include data on the TUS Airport Advisory Page with draws attention to the rising terrain around 'WASON' on the approach to Runway 11L; and the subsequent EGPWS potential (particularly on VFR Arrivals).


Second narrative: We were cleared for the visual approach to Runway 11L in Tucson; Arizona. I made a right downwind; then a right base; and then intercepted the localizer for the visual approach (backed up by the ILS) to Runway 11L. After calling the field in sight and subsequently cleared for the visual approach; I entered direct 'WASON' in the FMS and set 5;500 FT in the Altitude Window on the FCU; which I confirmed per the Approach Plate. As we were descending just outside of 'WASON' toward 5;000 FT and simultaneously intercepting the localizer; we received a GPWS 'Terrain' 'Pull-Up'. I immediately went TOGA and disconnected autopilot and climbed over 1;000 FT. At this point; since we were still 8 or 9 miles from the runway and still in a normal position to continue the approach to a normal VFR landing (still with ILS backup); I elected to continue the visual (ILS backup) approach to a normal landing and taxi-in. I believe I flew all the correct altitudes; consistent with the ILS Runway 11L step-down altitudes listed on the Approach Plate. Further; what I believed triggered the GPWS was the 4;565 FT obstacle located just outside of 'WASON' which we would've flown almost directly over during our controlled descent to 5;500 and 'dogleg' localizer intercept.Although I know about this issue and initially said to the First Officer that I wasn't going to call the field and have ATC vector me so that I would have the added barrier to keep clear of the terrain; I accepted the visual when ATC asked if I had the airport in sight. This set me up to get too close to the terrain. I was also fatigued from the long day and late hour and the night conditions. The pairing I was scheduled to do was a violation of the contract and possibly a violation of FAR 117 as scheduling extended us to the 14 hour limit as a matter of planning the pairing not as a matter of an 'unforeseen delay'.


Synopsis: A321 flight crew reports an EGPWS terrain warning approaching WASON on a visual ILS to TUS and takes evasive action. The FCU altitude had been correctly set to 5;500 FT but the EGPWS software was not aware of the planned level off and triggered the warning.