Hi, thank you for the help so far.
Its not, that I dont know how the reverse works.
What I ment was concerning the statement on this particular power point presentation, that during a low power setting on approach, ice can form on the fan blades either the forward or the aft side. Then when you land and pull the reverse, you increase the RPM N1 and N2 which is diffent to the low power setting and this might cause the formed ice to detach and then cause the damage.
Right ? Wrong?
Any other guesses