What was found
DURING FLIGHT 3036 WHILE CRUISING, FLIGHT AT 22,000 FT AND -20 DEGREES CELSIUS THE F/O AIRSPEED INDICATOR INCREASED SLOWLY TO 350 KIAS NO OVERSPEED WARNING WAS TRIGGERED, CAPT AND STBY AIRSPEED INDICATOR OPERATES NORMALLY. AIR RETURN TO MSP. MAINTENANCE DRAINED AND PURGED W/DRY NITROGEN NR 2 PITOT SYSTEM, REMOVED AND REPLACED NR 2 ASI. NR 2 PITOT STATIC SYSTEM AND NR 2 ASI TEST GOOD IAW SF340 MM CHAP 34. PITOT HEAT TEST GOOD.