A specialist at the Air Force Astronautics Laboratory at Edwards AFB, Calif., believes there were no blunders documented when Thiokol manufactured the MX first stage that failed.

But John H. Clark wrote in an Oct. 24, 1988, briefing paper that the Air Force's manufacturing rules were "loose enough to allow vast amounts of operator discretion" and should be tightened."This was most noticeable in the area of shear ply insulation buffing, where the operator subjectively decided how much buffing was sufficient to allow continuance of the process."

He thought the manufacturing regulations might have been so loose that "processing blunders could have been made but not documented."

Clark watched the process of manufacturing motors and the skirt installation for the MX first stage.

"It is worth noting from observing these processes, I saw no major discrepancies whereby operators did not follow the procedures. . . . What was noticed was the subjectivity of the operator in determining the level to which tasks were completed (i.e., buffing, resin coating), the poor lighting in the winding areas during operation on the case and skirt, and the overall positive attitude the workers had toward their work."