What was found
THE AIRCRAFT WAS GROUNDED. 4 MIN AFTER TAKEOFF, BELOW 10000 FT, LARGE AGGRESSIVE RHYTHMIC BANGING AND VIBRATION FELT IN AREA OF NOSE GEAR - 250 KTS AT TIME OF EVENT. AFTER SLOWING TO 220 KTS, AND FOR REMAINDER OF FLT, NOTHING ELSE. FLIGHT DECLARED AN EMERGENCY AND RETURNED TO PHX WITHOUT FURTHER INCIDENT. REPLACED RIGHT NOSE WHEEL ASSY PER AMM 32-41-12. RAN ENGINES, PACKS, HYDRAULICS, GALLEY COFFEE MAKER, AND CHILLER. PERFORMED WALK-AROUND OF A/C, ALL DOORS AND FAIRINGS SECURE. (R). SEE SDR AALA201811129014 FOR LEFT WHEEL ASSY.