Section 75.223 - Evaluation and revision of roof control plan(a) Revisions of the roof control plan shall be proposed by the operator- (1) When conditions indicate that the plan is not suitable for controlling the roof, face, ribs, or coal or rock bursts; or(2) When accident and injury experience at the mine indicates the plan is inadequate. The accident and injury experience at each mine shall be reviewed at least every six months.(b) Each unplanned roof fall and rib fall and coal or rock burst that occurs in the active workings shall be plotted on a mine map if it- (1) Is above the anchorage zone where roof bolts are used;(3) Impedes passage of persons;(4) Causes miners to be withdrawn from the area affected; or(5) Disrupts regular mining activities for more than one hour.(c) The mine map on which roof falls are plotted shall be available at the mine site for inspection by authorized representatives of the Secretary and representatives of miners at the mine.(d) The roof control plan for each mine shall be reviewed every six months by an authorized representative of the Secretary. This review shall take into consideration any falls of the roof, face and ribs and the adequacy of the support systems used at the time.53 FR 2375, Jan. 27, 1988; 60 FR 33723, June 29, 1995