Dependent upon type, model, and permitted aircraft weight variation, thresholds for repeated inspections occur between every 100 and 300 flight cycles and between every 400 and 1,500h (whichever comes first) for aircraft five years (or more) old on 24 September 2007. The most stringent requirement - every 200 cycles or 400h - covers certain China Southern Airlines A340-300s that are permitted to operate short flights at heavy weights between Chengdhu and Lhasa.
Source: Flight International