What was found
24 MONTH 91.411 & 91.413 TEST WAS DUE ON AIRCRAFT. WE PERFORM A PITOT LEAK CHECK PRIOR TO PERFORMING THE STATIC SYSTEM TESTS TO ENSURE OUR TEST EQUIPMENT WILL FUNCTION PROPERLY. WHEN SELECTING LEAK TEST MODE, I FOUND AN EXCESSIVE PITOT LEAK. TROUBLESHOOTING ISOLATED THE LEAK TO THE FORWARD NOSE AREA OF THE AIRCRAFT. WHEN I REMOVED THE PITOT TUBE, I FOUND THE RISER FROM THE PITOT TUBE TO BE CRACKED APPROXIMATELY 50% OF THE CIRCUMFERENCE OF THE TUBE. WE REPLACED THE TUBE WITH A SERVICEABLE UNIT AND THE PITOT SYSTEM TESTED SATISFACTORILY, PER MY TEST EQUIPMENT WE HAD A 0 KNOT PER MINUTE LEAK RATE. THE LOCATION OF THE PITOT TUBE AND PITOT LINE WERE LOCATED BELOW THE NOSE AVIONICS SHELF AND AHEAD OF AN AIR CONDITIONER CONDENSING COIL - THE CRACKED AREA WOULD NOT HAVE BEEN VISIBLE DURING A ROUTINE VISUAL INSPECTION.