A weakened zone of said tube section is automatically broken during lift off by {HEAD ~ a mechanism} applying {TAIL ~ a tensile stress} to the section 
A weakened zone of said tube section is automatically broken during lift off by { HEAD ~ a mechanism } applying { TAIL ~ a tensile stress } to the section
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH