scope:

Description of Driving Event:

On October 3, 1990, at approximately 0940 hours at the Vertical Assembly Building Transfer Aisle, the OV-104 Orbiter was being rotated toward the vertical position when three loud, thud noises were heard emanating from the Orbiter. IPR 38V-0182 was documented to investigate cause of the noise.

The three (3) thuds occurred in succession, not simultaneously. Discussions were held with Engineering, Operations, Technicians, and Quality personnel to determine possible causes of the noise.

A management decision was made to proceed with the soft mate of Orbiter to External Tank, visually inspect to verify Aft external tank attach nuts were in place prior to mate, mate Orbiter, remove weight of Orbiter from the attach sling (sling weight only on crane), open the Aft section and look for possible cause of noise.

All of the mate functions were accomplished and Aft Section 50-1 and 50-2 doors were removed to gain access to the Aft Compartment.

An avionics platform beam (G070-502677-001) was observed in the Aft Compartment.

Preliminary inspection indicated flight hardware had been damaged. Photographs were initially taken of the beam location and surrounding areas. As sufficient platforms were installed, additional photos were taken to document damage.

Beam G070-502677-001 was installed in the OPF by JC V35-00001 on August 15, 1990. This beam was verified as removed by Tech/Quality on October 1, 1990, prior to close-out of the Aft compartment to support roll-over from the OPF to the VAB for mating operations.