With regard to 25 May 1979, Chicago, I stand corrected.
Full understanding of discussion of the aircraft systems performance in the NTSB report (middle of p. 51 - 55) is beyond my reach. It nevertheless can be seen that the Board did find the airframe was flyable. I regret the posted error (and meant, positively, no aspersion upon the crew, none whatsoever).
https://www.ntsb.gov/investigations/...ts/AAR7917.pdf