TM 10-1670-287-23&P   0048 00 0048 00-3 (2)  Record the span measurement for each cell along with the corresponding cell identifier (i.e. Cell 1, 2, 3, etc.). (3)  Calculate the average cell span for the canopy.  Record this value. (4)  The relevant cell span measurements are: CANOPY MODEL LOWER LIMIT DESIRED RANGE UPPER LIMIT MC-4 47-inches 48 to 50-inches 50-inches MTl-X 45-inches 46 to 48-inches 48-inches MTl-S 47-inches 48 to 50-inches 50-inches (5)  Any canopy, that has a cell span, that falls below the corresponding lower limit or exceeds the upper limit, will be deemed unacceptable and will be immediately and permanently removed from service. c.    Procedure number 3.  Measurement of Top/Bottom Surface Span Differential: (1)  This procedure requires use of a tape measure.  In the same manner as above, measure and record the nose tape span for each cell along the bottom surface of the canopy from loaded rib to loaded rib. (2)  Calculate the sum of all top surface nose tape span measurements to determine the total top surface span.  Record this value. (3)  Calculate the sum of all bottom surface nose tape span measurements to determine the total bottom surface span.  Record this value. (4)  Subtract the total bottom surface span from the total top surface span to obtain a top/bottom surface span differential.  Record this value. (5)  Top/bottom surface span differentials should fall within the following ranges: CANOPY MODEL LOWER LIMIT DESIRED RANGE UPPER LIMIT MC-4 5-inches 6 ¹/₈ to 17 ½-inches 19-inches MTl-X 5-inches 6 to15-inches 17-inches MTl-S 3-inches 4 to13-inches 15-inches CELL 1 CELL 5 CELL 4 CELL 3 CELL 2 CELL 6 CELL 7 CELL SPAN TOTAL TOP SURFACE SPAN TOTAL BOTTOM SURFACE SPAN