from Tom's original site:
Five cords on the pink parachute had cut lines:
Line #7 had 186 ¾ inches of cord removed
Line #11 had 169 ¾ inches of cord removed
Line #12 had 169 inches of cord removed
Line #15 had 213 inches of cord removed
Line #22 had 217 ¼ inches of cord removed
The length of an uncut cord (including the double-sewn cord used to tie into the cross-connector, the bundle of cords located between the butterfly snap-hook rings in the reserve container) is 218 inches (or 18.2 feet).
Exactly how much suspension line is currently missing from the pink parachute?
955 ¾ inches (or 79.6 feet).
Exactly how much suspension line did D.B. Cooper use to wrap the bundle of money to his waist?
If the investigative search of the plane was conducted a mere 24 minutes after the plane touched down in Reno, NV and the number of cut cords recorded by the search team at that time was two, it suggests that Cooper removed two shroud lines (suspension lines) from the pink parachute. Logically, it seems as though the hijacker would grab two cords at the same time and make only one cut, rather than choosing lines individually and cutting them separately. Lines #11 and #12 seem the most plausible two, being a mere ¼ inch difference in length and located next to each other on the canopy. If D.B. Cooper took these two lines, he took a total of 338 ¾ inches (28.2 feet) of cord with him. If he doubled-up the cords for extra security during the jump, he used 169 ¾ inches (or 14.1 feet) of cord.
Two cords vs. Three cords
Whether two cords or three cords were cut remains a debate. Tina Mucklow asked the hijacker during the flight to cut some of the chute cord for her to possibly use as a safety line when the aft stairs were lowered, so as to not be sucked out of the plane [2]. Mucklow stated that Cooper informed her that she didn't need a cord. Was an additional cord cut from the chute at the time for Mucklow, but never used?
This research was conducted by Carol Abraczinskas, University of Chicago.