of additional detailed analysis of actual flight data concerning
descent-stress thermal-gradient loads, torsional straps were added
to tie all the lower midfuselage stringers in bays 1 through 11
together in a manner similar to a box section. This eliminates rotational
(torsional) capabilities to provide positive margins of safety.
Also, because of the detailed analysis of actual descent flight
data, room-temperature vulcanizing silicone rubber material was
bonded to the lower midfuselage from bays 4 through 11 to act
as a heat sink, distributing temperatures evenly across the bottom
of the midfuselage, reducing thermal gradients and ensuring positive
margins of safety.