v5p1196

Report of the PRESIDENTIAL COMMISSION on the Space Shuttle Challenger Accident

Volume 5 Index

Hearings of the Presidential Commission on the Space Shuttle Challenger Accident: February 26, 1986 to May 2, 1986.

MARCH 7, 1986 SESSION (part 2 of 2)

[1196] [Ref. 3/7-68 4 of 4] Failure Scenario 3.(continued).

FAILURE SCENARIO 3 (CONTINUED)

FINDINGS TO DATE:

DIFFICULTY EXPERIENCED IN MAKING 51-L AFT FIELD JOINT (4 TRYS)
- MECHANICAL ROUNDING FIXTURE REQUIRED

- WORSE CASE OCCURRENCE OF DATA REVIEWED TO DATE RELATIVE TO POTENTIAL FOR 0 RING/TANG INTERFERENCE

DIMENSIONAL TOLERANCE STACK-UP ANALYSIS COMPLETED
- METAL TO METAL INTERFERENCE (TANG ID WTIH CLEVIS INNER LEG SEALING SURFACES) WAS 0.0250 TO 0.209' BASED ON LAST MEASUREMENTS PRIOR TO MATE

THIS FAILURE MECHANISM REMAINS ACTIVE PENDING COMPLETION OF PAPER REVIEWS. CREW INTERVIEWS AND TESTS