The main in-flight aerodynamic forces on each wing were carried by pairs of cables to the front spar from the forward skid mounting point, an arrangement that caused some concern over the transfer of landing loads to the wing.
22.
To cope with the higher operating weights, the MD-83 incorporates strengthened landing gear including new wheels, tires, and brakes, changes to the wing skins, front spar web and elevator spar cap, and strengthened floor beams and panels to carry the auxiliary fuel tanks.
23.
Some fire damage found on the TWA jet's right-wing section is near the area of the front spar, where cracking and fuel leaks are known to occur, but senior investigators have said any leaking fuel most probably would have been detected by the cockpit crew.
24.
Scott and his party work out that " the bear " could refer to a lake, Dancing Bear Water, 30 or 40 miles back along the flight path of the lost aircraft and there, in due course, they find the tailplane and its front spar root, reveals a classic fatigue fracture.
25.
The 707 had been designed to a'fail-safe'philosophy, and failure of the tailplane rear spar had been calculated to be insufficient to cause the loss of the aircraft, the remaining front spar being sufficiently strong to enable the aircraft to land safely, the damage then being expected to be repaired before the aircraft was re-flown.
26.
Further complicated strutting joined the upper fuselage to the wing centre section : a pair diverged gently from ahead of the forward cockpit to the front spar, another strut joined that spar on the starboard side to the port upper longeron between the cockpits and yet another joined the rear spar to the fuselage in the opposite direction behind the rear cockpit.
