Narrative:

On takeoff roll; initially got a small airspeed split between captain's pfd and standby airspeed indication and first officer (first officer)'s pfd. Split was about 3-5 kts at 80; airspeed on captain's pfd kept increasing; the first officer called 'V1 and rotate'; I cross-checked with the standby airspeed and rotated normally. Captain pfd airspeed kept increasing; but as we were going faster; the split between pfd's got larger. Comparing captain and first officer airspeeds; we determined his was correct and raised the slats based upon first officer speed tape. Did the after takeoff checklist. Climbed and turned out using standby airspeed. First officer was looking at the 'unreliable airspeed' portion of the QRH when climbing through 3000 ft we got an engine 1 N1 fault; followed by an engine 2 N1 fault. I told the first officer; I'd fly the airplane while he ran the ECAM. Leveled at 7000 ft to trouble shoot the problem to get away from buildups that would have constantly required us to turn. Did the ECAM procedures; including turning off autothrottles. Called [operations] and [maintenance] to discuss the issue and determine whether to press on or not. I didn't get an air data computer fault; so I was reluctant to change air data computer systems without an ECAM or QRH requirement. After discussing the issue with [operations] and [maintenance]; first officer and I discussed the problems inherent with pressing on and I elected to return to ZZZ. Told departure that and we were vectored around for an uneventful landing to runway xy. There had to be some sort of pitot-static problem on the captain's side. There is probably some sort of linkage between the airspeed problems on the captain's pfd and the N1 faults on engine 1 and 2. While there was a small split between pfd speeds at 80kts; the speed split with increasing pfd speeds is insidious. My airspeed was increasing; and when the first officer called V1 and rotate; I was a bit surprised and I crossed checked the airspeed and decided not to reject because we were past V1 speed. On climb out; I kept my scan on my standby speed to not overspeed anything or exceed 250 below 10000 ft. The engine 1 & 2 N1 faults complicated the speed issue and trying to avoid the weather while troubleshooting made it a bit of a challenge. I think returning to ZZZ was still the right answer. We were reluctant to press on with the adverse weather enroute with a possible pitot-static problem. I thought I would receive an air data computer failure ECAM; if there were air data computer issues. I did not declare an emergency and in retrospect; I should have. While I had two good engines and good hydraulics; I should have declared in case there were any problems. Additionally; I will be more exacting in airspeed calls.

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Original NASA ASRS Text

Title: A300 Captain reported a pitot static system anomaly that resulted in an inaccurate airspeed indicator. Flight returned to departure airport.

Narrative: On takeoff roll; initially got a small airspeed split between Captain's PFD and standby airspeed indication and First Officer (FO)'s PFD. Split was about 3-5 kts at 80; airspeed on Captain's PFD kept increasing; the FO called 'V1 and Rotate'; I cross-checked with the standby airspeed and rotated normally. Captain PFD airspeed kept increasing; but as we were going faster; the split between PFD's got larger. Comparing Captain and FO airspeeds; we determined his was correct and raised the slats based upon FO speed tape. Did the after takeoff checklist. Climbed and turned out using standby airspeed. FO was looking at the 'unreliable airspeed' portion of the QRH when climbing through 3000 ft we got an Engine 1 N1 Fault; followed by an Engine 2 N1 fault. I told the FO; I'd fly the airplane while he ran the ECAM. Leveled at 7000 ft to trouble shoot the problem to get away from buildups that would have constantly required us to turn. Did the ECAM procedures; including turning off autothrottles. Called [operations] and [maintenance] to discuss the issue and determine whether to press on or not. I didn't get an ADC fault; so I was reluctant to change ADC systems without an ECAM or QRH requirement. After discussing the issue with [operations] and [maintenance]; FO and I discussed the problems inherent with pressing on and I elected to return to ZZZ. Told departure that and we were vectored around for an uneventful landing to Runway XY. There had to be some sort of pitot-static problem on the Captain's side. There is probably some sort of linkage between the airspeed problems on the Captain's PFD and the N1 faults on Engine 1 and 2. While there was a small split between PFD speeds at 80kts; the speed split with increasing PFD speeds is insidious. My airspeed was increasing; and when the FO called V1 and Rotate; I was a bit surprised and I crossed checked the airspeed and decided not to reject because we were past V1 speed. On climb out; I kept my scan on my standby speed to not overspeed anything or exceed 250 below 10000 ft. The Engine 1 & 2 N1 faults complicated the speed issue and trying to avoid the weather while troubleshooting made it a bit of a challenge. I think returning to ZZZ was still the right answer. We were reluctant to press on with the adverse weather enroute with a possible pitot-static problem. I thought I would receive an ADC failure ECAM; if there were ADC issues. I did not declare an emergency and in retrospect; I should have. While I had two good engines and good hydraulics; I should have declared in case there were any problems. Additionally; I will be more exacting in airspeed calls.

Data retrieved from NASA's ASRS site 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.