A huge eruptive prominence was observed on March 18 at 0506 UT,which extended to more than 500,000 km above the eastern limb.Several knots of material were observed to be ascending with very high velocities. This is an example of "disparition brusque" seen on the limb. The frame at 0513 UT shows a helical structure which gradually straightened out as seen at 0520 UT.