What was found
WHILE HOVERING FOR TAKE OFF, A NOTICEABLE BANG CAME FROM THE ENGINE COMPARTMENT AND A RIGHT YAW OCCURRED. AIRCRAFT CONTROL WAS MAINTAINED AND SYSTEMS INSTRUMENTS WERE IN THE GREEN. AIRCRAFT WAS THEN HOVERED TO THE MAINTENANCE PAD AND SHUT DOWN. MAINTENANCE FOUND COMPRESSOR BLEED VALVE AIR LINE LOOSE, TIGHTEN AIR LINE AND COMPLIED WITH MFG PNEUMATIC AIR LINE CHECK. INSPECTED COMPRESSOR AREA FOR FOD DAMAGE FOUND NONE, AIRCRAFT WAS GROUND RUN AND LEAK CHECKED AND OPS CHECK FLOWN GOOD.