I think to answer the original question, in basic terms:
A check: daily inspection
B check: 50 hrs
C check: roughly every 12-14 months, requiring approximatly 3-6 weeks down time
D check: can't remember the interval here, 4-5 years rings a bell. Requires a reasonbly comprehensive rebuild.
Sorry for any errors, but I thought this got back to the original question. Mayby someone with more knowledge than me can flesh it out a little bit.
d.